Service Manual2011 Aveo DIAGNOSIS

Aveo

DIAGNOSIS

SYSTEM DIAGNOSIS

Diagnostic Aids

If an intermittent problem is evident, follow the guidelines below.

Preliminary Checks

Before using this section you should have already performed the "On-Board Diagnostic System Check."

Perform a thorough visual inspection. This inspection can often lead to correcting a problem without further checks and can save valuable time. Inspect for the following conditions:

Engine control module (ECM) grounds for being clean, tight, and in their proper location.
Vacuum hoses for splits, kinks, collapsing and proper connections as shown on the Vehicle Emission Control Information label. Inspect thoroughly for any type of leak or restriction.
Air leaks at the throttle body mounting area and the intake manifold sealing surfaces.
Ignition wires for cracks, hardness, proper routing, and carbon tracking.
Wiring for proper connections.
Wiring for pinches or cuts.

Diagnostic Trouble Code Tables

Do not use the Diagnostic Trouble Code (DTC) tables to try to correct an intermittent fault. The fault must be present to locate the problem.

Incorrect use of the DTC tables may result in the unnecessary replacement of parts.

Faulty Electrical Connections or Wiring

Most intermittent problems are caused by faulty electrical connections or wiring. Perform a careful inspection of suspect circuits for the following:

Poor mating of the connector halves.
Terminals not fully seated in the connector body.
Improperly formed or damaged terminals. All connector terminals in a problem circuit should be carefully inspected, reformed, or replaced to insure contact tension.
Poor terminal-to-wire connection. This requires removing the terminal from the connector body.

Road Test

If a visual inspection does not find the cause of the problem, the vehicle can be driven with a voltmeter or a scan tool connected to a suspected circuit. An abnormal voltage or scan tool reading will indicate that the problem is in that circuit.

If there are no wiring or connector problems found and a DTC was stored for a circuit having a sensor, except for DTC P0171 and DTC P0172, replace the sensor.

Fuel System

Some intermittent driveability problems can be attributed to poor fuel quality. If a vehicle is occasionally running rough, stalling, or otherwise performing badly, ask the customer about the following fuel buying habits:

Do they always buy from the same source? If so, fuel quality problems can usually be discounted.
Do they buy their fuel from whichever fuel station that is advertising the lowest price? If so, check the fuel tank for signs of debris, water, or other contamination.

Idle Learn Procedure

The following idle learn procedure must be performed whenever one or more of the actions listed below are taken;

- Replacement of new ECM

- Replacement of new IAC valve

- Cleaning of carbon deposit on the throttle body

Turn the ignition ON.
Turn the ignition OFF for 15 seconds.
Turn the ignition ON for 5 seconds.
Turn the ignition OFF for 15 seconds.
Start the engine in park/neutral.
If the vehicle is equipped with an automatic transaxle, apply the parking brake. While pressing the brake pedal, place the transaxle in D (Drive) for 1 second and return to P (Park). (Siemens ECM only).
Allow the engine to run until the engine coolant is above 85°C (185°F).
Turn the A/C ON for 10 seconds, if equipped.
If the vehicle is equipped with an automatic transaxle, apply the parking brake. While pressing the brake pedal, place the transaxle in D (drive) for 10 seconds.
Turn the A/C OFF for 10 seconds, if equipped.
If the vehicle is equipped with an automatic transaxle, while pressing the brake pedal, place the transaxle in park/neutral.
Turn the ignition OFF. The idle learn procedure is complete.
Wait for 15 seconds before restarting the engine (Siemens ECM only).

TEC (TOOTH ERROR CORRECTION) Learn Procedure

When an ECM is reflashed, initialized or replaced, and driveplate of fly wheel has been replaced, follow these procedures to relearn the crankshaft position (CKP) system variation :

Caution : To avoid personal injury when performing the TEC learn procedure, always set the vehicle parking brake and block the drive wheels. Release the throttle immediately when the engine starts to decelerate. Once the learning procedure is completed, engine control will be learned to the operator, and the engine will respond to throttle position.

Place the gear position in park or neutral.
Install the scan tool and select "TEC (Toth Error Correction) LEARN" menu.
Start the engine with A/C off.
Keep the engine coolant temperature above 65°C (149° F)
Put the acceleration pedal above 4000 RPM until the fuel cut-off occurs.
Wait 10-15 seconds.
Fulfill this procedure again if the scan tool does not display "OK" message.
Turn the ignition switch OFF.
Turn the ignition swtich ON and then clear the DTC code.

ON-Board Diagnostic System Check (1.2L DOHC)

Circuit Description

The On-Board Diagnostic system check is the starting point for any driveability complaint diagnosis. Before using this procedure, perform a careful visual/physical check of the engine control module (ECM) and the engine grounds for cleanliness and tightness.

The OBD system check is an organized approach to identifying a problem created by an electronic engine control system malfunction.

Diagnostic Aids

An intermittent may be caused by a poor connection, rubbed-through wire insulation or a wire broken inside the insulation. Check for poor connections or a damaged harness. Inspect the ECM harness and connections for improper mating, broken locks, improperly formed or damaged terminals, poor terminal-to-wire connection, and damaged harness.

Test Description

Numbers below refer to the step number on the Diagnostic Chart:

The Malfunction Indicator Lamp (MIL) should be ON steady with the ignition ON and the engine OFF. If not, go to "Diagnostic Aids".
Checks the Class 2 data circuit and ensures that the ECM is able to transmit serial data.
This test ensures that the ECM is capable of controlling the MIL and the MIL driver circuit is not shorted to ground.
If the engine will not start, refer to "Engine Cranks But Will Not Run" in this section.
A scan tool parameter which is not within the typical range may help to isolate the area which is causing the problem.
This vehicle is equipped with a ECM which utilizes an Electrically Erasable Programmable Read Only Memory (EEPROM). The replacement ECM must be programmed. Refer to the latest Techline procedure for ECM reprogramming.

On-Board Diagnostic System Check (1.2L DOHC)

Step	Action	Value(s)	Yes	No
1	Turn the ignition switch to ON. Observe the Malfunction Indicator Lamp (MIL). Is the MIL illuminate?	-	Go to Step 2	Go to "No Malfunction Indicator Lamp"
2	Turn the ignition switch to LOCK. Install the scan tool to the Data link Connector (DLC). Turn the ignition switch to ON. Attempt to display the Engine Control Module (ECM) engine data with the scan tool. Does the scan tool display the ECM engine data?	-	Go to Step 3	Go to Step 8
3	Using the scan tool output test function, select the MIL lamp control and command the MIL off. Observe the MIL. Does the MIL turn OFF?	-	Go to Step 4	Go to "Malfunction Indicator Lamp on Steady"
4	Attempt to start the engine. Does the engine start and continue to run?	-	Go to Step 5	Go to "Engine Cranks But Will Not Run"
5	Select DISPLAY DTC with the scan tool. Are any Diagnostic Trouble Codes (DTCs) stored?	-	Go to Step 6	Go to Step 7
6	Check the display for DTCs P0107, P0108, P0113, P0118, P0122, P0123, P0712, P1392. Are two or more of the following DTCs stored?	-	Go to "Multiple ECM Information Sensor DTCs Set"	Go to applicable DTC table
7	Compare the ECM data values displayed on the scan tool to the typical engine scan data values. Are the displayed values normal or close to the typical values?	-	Go to "ECM Output Diagnosis"	Go to indicated component system check
8	Turn the ignition switch to LOCK. Disconnect the ECM connector. Turn the ignition switch to ON. Check the serial data circuit for an open, short to ground, or short to voltage. Also check the DLC ignition feed circuit for an open or short to ground, and check the DLC ground circuits for an open. Is a problem found?	-	Go to Step 9	Go to Step 10
9	Repair the open, short to ground, or short to voltage in the serial data circuit or the DLC ignition feed circuit. Is the repair complete?	-	System OK	-
10	Attempt to reprogram the ECM. Attempt to display the ECM data with the scan tool. Does the scan tool display ECM engine data?	-	Go to Step 2	Go to Step 11
11	Replace the ECM. Is the replacement complete?	-	System OK	-

Multiple ECM Information Sensor DTCs Set

Circuit Description

The Engine Control Module (ECM) monitors various sensors to determine engine operating conditions. The ECM controls fuel delivery, spark advance, transaxle operation, and emission control device operation based on the sensor inputs.

The ECM provides a sensor ground to all of the sensors. The ECM applies 5 volts through a pull-up resistor and monitors the voltage present between the sensor and the resistor to determine the status of the Engine Coolant Temperature (ECT) sensor, the Intake Air Temperature (IAT) sensor. The ECM provides the Exhaust Gas Recirculation (EGR) Pintle Position Sensor, the Throttle Position (TP) sensor, the Manifold Absolute Pressure (MAP) sensor, and the Fuel Tank Pressure Sensor with a 5 volt reference and a sensor ground signal. The ECM monitors the separate feedback signals from these sensors to determine their operating status.

Diagnostic Aids

Be sure to inspect the ECM and the engine grounds for being secure and clean.

A short to voltage in one of the sensor circuits can cause one or more of the following DTCs to be set: P0108, P0113, P0118, P0123, P0463, P0533.

If a sensor input circuit has been shorted to voltage, ensure that the sensor is not damaged. A damaged sensor will continue to indicate a high or low voltage after the affected circuit has been repaired. If the sensor has been damaged, replace it.

An open in the sensor ground circuit between the ECM and the splice will cause one or more of the following DTCs to be set: P0107, P0108, P0113, P0118, P0122, P0123, P0462, P0532.

A short to ground in the 5 volt reference circuit or an open in the 5 volt reference circuit between the ECM and the splice will cause one or more of the following DTCs to be set: P0107, P0112, P0117, P0122, P0462, P0532.

Check for the following conditions:

Inspect for a poor connection at the ECM. Inspect harness connectors for backed-out terminals, improper mating, broken locks, improperly formed or damaged terminals, and poor terminal-to-wire connection.
Inspect the wiring harness for damage. If the harness appears to be OK, observe an affected sensor's displayed value on the scan tool with the ignition ON and the engine OFF while moving connectors and wiring harnesses related to the affected sensors. A change in the affected sensor's displayed value will indicate the location of the fault.

Test Description

Number(s) below refer to the step number(s) on the Diagnostic Table.

The Powertrain On-Board Diagnostic System Check prompts the technician to complete some basic checks and store the freeze frame and failure records data on the scan tool if applicable. This creates an electronic copy of the data taken when the malfunction occurred. The information is then stored on the scan tool for later reference.
A faulty EGR valve can leak a small amount of current from the ignition feed circuit to the 5 volt reference circuit. If the problem does not exist with the EGR valve disconnected, replace the EGR valve.
If a sensor input circuit has been shorted to voltage, ensure that the sensor has not been damaged. A damaged IAT or ECT sensor will continue to indicate a high voltage or low temperature after the affected circuit has been repaired. A damaged ACT, TP, MAP, Fuel Tank Pressure, or EGR Pintle Position sensor will indicate a high or low voltage or may be stuck at a fixed value after the affected circuit has been repaired. If the sensor has been damaged, replace it.
The replacement ECM must be reprogrammed. Refer to the latest Techline procedure for ECM reprogramming.

Multiple ECM Information Sensor DTCs Set

Step	Action	Value(s)	Yes	No
1	Perform an On-Board Diagnostic system check. Is the check complete.	-	Go to Step 2	Go to "On-Board Diagnostic System Check"
2	Turn the ignition switch to LOCK. Disconnect the Engine Control Module (ECM) connector. Turn the ignition switch to ON. Check the 5V reference circuit for the following conditions: Poor connection at the ECM. Open between the ECM connector affected sensors shorted to ground or voltage. If a problem is found, locate and repair the open or short circuit as needed. Is a problem found?	-	Go to Step 19	Go to Step 3
3	Check the sensor ground circuit for the following conditions: Poor connection at the ECM or affected sensors. Open between the ECM connector and the affected sensors. If a problem is found, repair it as needed. Is a problem found?	-	Go to Step 19	Go to Step 4
4	Measure the voltage of the Exhaust Gas Recirculation (EGR) Pintle Position Sensor signal circuit between ECM harness connector and ground. Does the voltage near the specified value?	0 V	Go to Step 5	Go to Step 9
5	Measure the voltage of the Manifold Absolute Pressure (MAP) sensor signal circuit between the ECM harness connector and ground. Does the voltage near the specified value?	0 V	Go to Step 6	Go to Step 12
6	Measure the voltage of the Throttle Position (TP) sensor signal circuit between the ECM harness connector and ground. Does the voltage near the specified value?	0 V	Go to Step 7	Go to Step 12
7	Measure the voltage of the Intake Air Temperature (IAT) sensor signal circuit between the ECM harness connector and ground. Does the voltage near the specified value?	0 V	Go to Step 8	Go to Step 13
8	Measure the voltage of the Engine Coolant Temperature (ECT) sensor signal circuit between the ECM harness connector and ground. Does the voltage near the specified value?	0 V	Go to Step 16	Go to Step 14
9	Disconnect the EGR valve connector. Measure the voltage of the EGR Pintle Position sensor signal circuit between the ECM harness connector and ground. Does the voltage near the specified value?	0 V	Go to Step 10	Go to Step 15
10	Replace the EGR valve. Is the replacement complete?	-	Go to Step 19	-
11	Locate and repair the short to voltage in the MAP sensor signal circuit. Is the repair complete?	-	Go to Step 19	-
12	Locate and repair the short to voltage in the TP sensor signal circuit. Is the repair complete?	-	Go to Step 19	-
13	Locate and repair the short to voltage in the IAT sensor signal circuit. Is the repair complete?	-	Go to Step 19	-
14	Locate and repair the short to voltage in the ECT sensor signal circuit. Is the repair complete?	-	Go to Step 19	-
15	Locate and repair the short to voltage in the EGR Pintle Position sensor circuit. Is the repair complete?	-	Go to Step 19	-
16	Measure the voltage of the fuel tank pressure sensor signal circuit between the ECM harness connector and ground. Does the voltage near the specified value?	0 V	Go to Step 18	Go to Step 17
17	Locate and repair the short to voltage in the fuel tank pressure sensor signal circuit. Is the replacement complete?	-	Go to Step 19	-
18	Replace the ECM. Is the repair complete?	-	Go to Step 19	-
19	Using the scan tool, clear the Diagnostic Trouble Codes (DTCs). Start the engine and idle at normal operating temperature. Operate the vehicle within the conditions for setting the DTCs as specified in the supporting text. Does the scan tool indicate that this diagnostic ran and passed?	-	Go to Step 20	Go to Step 2
22	Check if any additional DTCs are set. Are any DTCs displayed that have not been diagnosed?	-	Go to applicable DTC table	System OK

Engine Cranks But Will Not Run (1.2L DOHC)

Test Description

The number(s) below refer to step(s) on the diagnostic table.

The On-Board Diagnostic System Check prompts the technician to complete some basic checks and store the freeze frame and failure records data on the scan tool if applicable. This creates an electronic copy of the data taken when the occurred. The information is then stored on the scan tool for later reference.
The On-Board Diagnostic System Check prompts the technician to complete some basic checks and store the freeze frame and failure records data on the scan tool if applicable. This creates an electronic copy of the data taken when the occurred. The information is then stored on the scan tool for later reference.
By performing a compression test, it can be determined if the engine has the mechanical ability to run.
By performing a compression test, it can be determined if the engine has the mechanical ability to run.
It is important to check for the presence of spark from all of the ignition wires. If spark is present from one to three of the ignition coil terminals, the Crankshaft Position (CKP) sensor is OK.
It is important to check for the presence of spark from all of the ignition wires. If spark is present from one to three of the ignition coil terminals, the Crankshaft Position (CKP) sensor is OK.

In checking the engine control module (ECM) outputs for the electronic spark timing signal, it recommended to use an oscilloscope to view the varying voltage signals. In measuring these outputs with a voltmeter, intermittent errors may occur that cannot be seen by a voltmeter.
This step checks for proper operation of the ECM's control of the fuel pump circuit.
This step checks for a ground signal being supplied by the ECM to operate the fuel injectors. If there is no ground present during the cranking of the engine, and the fuel injector wiring is OK, the ECM is at fault.

Engine Cranks But Will Not Run (1.2L DOHC)

Caution : Use only electrically insulated pliers when handling ignition wires with the engine running to prevent an electrical shock.

Caution : Do not pinch or restrict nylon fuel lines. Damage to the lines could cause a fuel leak, resulting in possible fire or personal injury.

Step	Action	Value(s)	Yes	No
1	Perform an On-Board Diagnostic System Check. Is the check complete.	-	Go to Step 2	Go to "On-Board Diagnostic System Check"
2	Crank the engine. Does the engine start and continue to run?	-	System OK	Go to Step 3
3	Perform a cylinder compression test. Is the cylinder compression for all of the cylinders at or above the value specified?	689 kPa (100 psi)	Go to Step 7	Go to Step 4
4	Inspect the timing belt alignment. Is the timing belt in alignment?	-	Go to Step 6	Go to Step 5
5	Align or replace the timing belt as needed. Is the repair complete?	-	Go to Step 2	-
6	Repair internal engine damage as needed. Is the repair complete?	-	Go to Step 2	-
7	Inspect the fuel pump fuse. Is the problem found?	-	Go to Step 8	Go to Step 9
8	Replace the fuse. Is the repair complete?	-	Go to Step 2	-
9	Check for the presence of spark from all of the ignition wires while cranking the engine. Is spark present from all of the ignition wires?	-	Go to Step 23	Go to Step 10
10	Measure the resistance of the ignition wires. Replace any of the ignition wire(s) with a resistance above the value specified. Check for the presence of spark from all of the ignition wire. Is spark present from all of the ignition wires?	30000 Ω	Go to Step 2	Go to Step 11
11	Turn the ignition OFF. Disconnect the crankshaft position (CKP) sensor connector. Turn the ignition ON. Measure the voltage between following terminals: Terminal 1 and 3 of the CKP sensor connector. Terminal 2 and 3 of the CKP sensor connector. Terminal 1 of the CKP sensor connector and ground. Terminal 2 of the CKP sensor connector and ground. Are the voltage measure within the value specified?	≈ 1.4 V	Go to Step 13	Go to Step 12
12	Check for an open or short in the wires between CKP sensor connector and ECM connector and repair as need. Is the repair complete?	-	Go to Step 2	-
13	Disconnect electronic Ignition (EI) system ignition coil connector to prevent the vehicle from starting. Measure the voltage at ECM connector terminal 85 and 54 by backprobing the ECM connector. Are the voltage readings near the value specified?	1.4V with ignition ON, 1.6V during cranking	Go to Step 15	Go to Step 14
14	Replace the CKP sensor. Is the repair complete?	-	Go to Step 2	-
15	Turn the ignition OFF. Disconnect the electrical connector at EI system ignition coil. Connect a test light between terminal B of the EI system ignition coil connector and ground. Turn the ignition ON. Is the test light on?	-	Go to Step 17	Go to Step 16
16	Check for open in wire between the battery and EI system ignition coil connector terminal B and repair as needed. Is the repair complete?	-	Go to Step 2	-
17	Turn the ignition OFF. Disconnect ECM connect and EI system ignition coil connector. Measure the resistance between following terminals: Terminal A of ignition coil and terminal 31 of ECM connector. Terminal C of ignition coil and terminal 32 of ECM connector. Are the resistance within the value specified?	0 Ω	Go to Step 19	Go to Step 18
18	Check for open circuit and repair as needed. Is the repair complete?	-	Go to Step 2	-
19	Measure the resistance between following terminals: Terminal A and B of ignition coil. Terminal B and C of ignition coil. Are the resistance within the value specified. Remove the high tension cable. Measure the resistance between second coil. Between 1 and 4 Between 2 and 3 Are the resistance within the value specified.	0.9 Ω 5.3 kΩ	Go to Step 21	Go to Step 20
20	Replace the EI system ignition coil. Is the repair complete?	-	Go to Step 2	-
21	Check for any damages or poor connection in ignition wires and repair as needed. Connect the EI system ignition coil connector and ECM connector. Check for the presence of spark from all of the ignition wires. Is the spark present from all of the ignition wires?	-	Go to Step 2	Go to Step 22
22	Replace ECM. Is the repair complete?	-	Go to Step 2	-
23	Turn the ignition OFF. Connect a fuel pressure gauge. Crank the engine. Is any fuel pressure present?	-	Go to Step 26	Go to Step 24
24	Turn the ignition OFF. Disconnect the electrical connector at the fuel pump. Connect a test light between the fuel pump terminals 2 and 3. Turn the ignition ON. With the ignition ON, the test light should light for the time specified. Is the test light on?	2 sec.	Go to Step 25	Go to Step 34
25	Replace the fuel pump. Is the repair complete?	-	Go to Step 2	-
26	Is the fuel pressure within the value specified?	283-324 kPa (41-47 psi)	Go to Step 27	Go to Step 29
27	Check the fuel for contamination. Is the fuel contaminated?	-	Go to Step 28	Go to Step 41
28	Remove the contaminated fuel from the fuel tank. Clean the fuel tank as needed. Is the repair complete?	-	Go to Step 2	-
29	Check the fuel filter for restriction. Inspect the fuel lines for kinks and restrictions. Repair or replace as needed. Measure the fuel pressure. Is the fuel pressure within the value specified?	283-324 kPa (41-47 psi)	Go to Step 2	Go to Step 30
30	Disconnect vacuum line from the fuel pressure regulator. Inspect the vacuum line for the presence of fuel. Inspect the fuel pressure regulator vacuum port for the presence of fuel. Is any fuel present?	-	Go to Step 31	Go to Step 32
31	Replace the fuel pressure regulator. Is the repair complete?	-	Go to Step 2	-
32	Remove the fuel pump assembly from the fuel tank. Inspect the fuel pump sender and the fuel coupling hoses for a restriction. Inspect the in-tank fuel filter for restriction. Is the problem found?	-	Go to Step 33	Go to Step 25
33	Replace the fuel pump sender, the in-tank fuel filter, and/or the fuel coupling hoses as needed. Is the repair complete?	-	Go to Step 2	-
34	Turn the ignition OFF. Disconnect the electric connector at the fuel pump. Connect a test light between fuel pump connector terminal 3 and ground. Turn the ignition ON. With the ignition ON, the test light should illuminate for the time specified. Is the test light on?	2 sec	Go to Step 35	Go to Step 36
35	Repair the open circuit between the fuel pump connector terminal 2 and ground. Is the repair complete?	-	Go to Step 2	-
36	Turn the ignition OFF. Disconnect the fuel pump relay. Turn the ignition ON. Measure the voltage at terminal 30 and 85 of fuel pump relay. Is the voltage within the value specified?	11-14 V	Go to Step 38	Go to Step 37
37	Repair open or short circuit for power supply. Is the repair complete?	-	Go to Step 2	-
38	Turn the ignition OFF. Disconnect ECM connector. Using an ohmmeter, measure the resistance between following terminals. Terminal 6 of ECM and terminal 86 of fuel pump relay. Terminal 87 of fuel pump relay and terminal 3 of fuel pump. Does the resistance within the value specified?	0 Ω	Go to Step 40	Go to Step 39
39	Repair the open or short circuit the following terminals. Terminal 6 of ECM and terminal 85 of fuel pump relay. Terminal 87 of fuel pump relay and terminal 3 of fuel pump. Is the repair complete?	-	Go to Step 2	-
40	Replace the fuel pump relay. Is the repair complete?	-	Go to Step 2	-
41	Turn the ignition OFF. Disconnect the fuel inject harness connectors from all of the fuel injectors. Turn the ignition ON. Connect test light between fuel injector harness connector 2 and ground. Repeat step 4 for each of the remaining fuel injectors. Does the test light on at all of the fuel injectors?	-	Go to Step 42	Go to Step 45
42	Turn the ignition OFF. Connect test light between fuel injector harness connector 1 and battery positive. Crank the engine. Repeat step 2 and 3 for each of the remaining fuel injectors. Does the test light flash for all of the fuel injectors?	-	Go to Step 43	Go to Step 46
43	Measure the resistance of each fuel injectors. Is the resistance within the value specified. Notice : the resistance will increase slightly at higher temperature.	11.6-12.4Ω	System OK	Go to Step 44
44	Replace any of the fuel injectors with a resistance out of specification. Is the repair complete?	-	Go to Step 2	-
45	Inspect the fuse Ef13 in engine fuse block. Check for an open between the circuit from terminal 2 of the four fuel injectors and terminal 87 of main relay. Is the problem found?	-	Go to Step 48	Go to "Main Relay Circuit Check"
46	Measure the resistance between following terminals. Terminal 2 of injector 1 connector and terminal 59 of ECM connector. Terminal 2 of injector 2 connector and terminal 89 of ECM connector. Terminal 2 of injector 3 connector and terminal 90 of ECM connector. Terminal 2 of injector 4 connector and terminal 60 of ECM connector. Does the resistance within the specified value?	0 Ω	Go to Step 49	Go to Step 47
47	Repair the open fuel injector harness wire(s). Is the repair complete?	-	Go to Step 2	-
48	Replace the fuse or repair the wiring as needed. Is the repair complete?	-	Go to Step 2	-
49	Replace the ECM. Is the repair complete?	-	Go to Step 2	-

No Malfunction Indicator Lamp (1.2L DOHC)

Circuit Description

When the ignition is turned ON, the Malfunction Indicator Lamp (MIL) will be turned ON and remain ON until the engine is running, if no Diagnostic Trouble Codes (DTCs) are stored. Battery voltage is supplied through the ignition switch directly to the MIL telltale. The Engine Control Module (ECM) controls the MIL by providing a ground path through the MIL control circuit to turn ON the MIL.

Diagnostic Aids

An open ignition fuse F3 will cause the entire cluster to be inoperative.

Check the battery and ignition feed circuits for poor connections if the MIL is intermittent.

Any circuitry, that is suspected as causing an intermittent complaint, should be thoroughly checked for backed-out terminals, improper mating, broken locks, improperly formed or damaged terminals, poor terminal-to-wiring connections or physical damage to the wiring harness.

No Malfunction Indicator Lamp (1.2L DOHC)

Step	Action	Value(s)	Yes	No
1	Attempt to start the engine. Does the engine start?	-	Go to Step 2	Go to "Engine Cranks But Will Not Run"
2	Turn the ignition switch to LOCK. Disconnect the Engine Control Module (ECM) connector. Turn the ignition switch to ON. Connect a test light between the ECM connector terminal 39 and ground. Is the test light illuminate?	-	Go to Step 3	Go to Step 6
3	Check terminals for damage or poor connection. Does any problem found?	-	Go to Step 5	Go to Step 4
4	Replace the ECM. Is the replacement complete?	-	Go to "On-Board Diagnostic System Check"	-
5	Repair any damaged terminals or poor connection. Is the repair complete?	-	Go to "On-Board Diagnostic System Check"	-
6	Check the fuse F3. Is the fuse open?	-	Go to Step 7	Go to Step 8
7	Check for a short to ground in the circuit and repair as needed. Replace the fuse F3. Is the repair or replacement complete?	-	Go to "On-Board Diagnostic System Check"	-
8	Check for an open circuit between fuse F3 and the ECM connector terminal 39 and repair as needed. Check the MIL bulb and replace if open. Is the repair or replacement complete?	-	Go to "On-Board Diagnostic System Check"	-

Malfunction Indicator Lamp On Steady (1.2L DOHC)

Circuit Description

When the ignition switch is turned ON, the Malfunction Indicator Lamp (MIL) will be turned ON and remain ON until the engine is running, if no Diagnostic Trouble Codes (DTCs) are stored. Battery voltage is supplied through the ignition switch directly to the MIL telltale. The Engine Control Module (ECM) controls the MIL by providing a ground path through the MIL control circuit to turn ON the MIL.

Test Description

Number(s) below refer to the step number(s) on the diagnostic table.

The On-Board Diagnostic System Check prompts the technician to complete some basic checks and store the freeze frame and failure records data on the scan tool, if applicable. This creates an electronic copy of the data taken when the malfunction occurred. The information is stored in the scan tool for later reference.
When the ignition is turned ON, the MIL should be turned on and remain on until the engine is running or if an emission related DTC is stored. This step checks the ability of the ECM to control the MIL. The scan tool has the ability to command the MIL on and off.
A shorted MIL circuit can be diagnosed with a scan tool.
The replacement ECM must be reprogrammed. Refer to the latest Techline information for reprogramming procedures.

Malfunction Indicator Lamp On Steady (1.2L DOHC)

Step	Action	Value(s)	Yes	No
1	Perform an On-Board Diagnostic system check. Is the check complete.	-	Go to Step 2	Go to "On-Board Diagnostic System Check"
2	Turn the ignition switch to LOCK. Install the scan tool to the Data Link Connector (DLC). Command the Malfunction Indicator Lamp (MIL) ON and OFF. Does the MIL turn ON and OFF when commanded?	-	Go to Step 7	Go to Step 3
3	Turn the ignition switch to LOCK. Disconnect the Engine Control Module (ECM) connector. Turn the ignition switch to ON. Is the MIL off?	-	Go to Step 6	Go to Step 4
4	Check the MIL control circuit for a short to ground and repair as needed. Is the repair complete?	-	Go to Step 7	Go to Step 5
5	Replace the instrument panel cluster. Refer to Section 9E, Instrumentation/Driver Information. Is the repair complete?	-	Go to Step 7	-
6	Replace the ECM. Is the repair complete?	-	Go to Step 7	-
7	Using the scan tool, clear the Diagnostic Trouble Codes(DTCs). Attempt to start the engine. Does the engine start and continue to run?	-	Go to Step 8	Go to Step 1
8	Allow the engine to idle until normal operating temperature is reached. Check if any DTCs are set. Are any DTCs displayed that have not been diagnosed?	-	Go to Applicable DTC table	System OK

Fuel System Diagnosis (1.2L DOHC)

Circuit Description

The fuel pump is an in-tank type mounted to a fuel sender assembly. The fuel pump will remain on as long as the engine is cranking or running and the Engine Control Module (ECM) is receiving reference pulses from the crankshaft position (CKP) sensor. If there are no reference pulses, the ECM will turn off the fuel pump two seconds after the ignition switch is turned ON or two seconds after the engine stops running. The fuel pump delivers fuel to the fuel rail and the fuel injectors, where the fuel system pressure is controlled from 379 to 393 kPa (55 to 57 psi) by the fuel pressure regulator. The excess fuel is returned to the fuel tank.

Test Description

The number(s) below refer to step(s) on the diagnostic table.

When the engine is idling, the intake manifold vacuum is high. This vacuum is applied to the fuel pressure regulator diaphragm, offsetting the spring pressure inside the fuel pressure regulator and lowering the fuel pressure.
If there is fuel bleeding back through the fuel return outlet, this is due to a faulty fuel pressure regulator.
Another symptom often present when the fuel injectors are leaking is hard starting. Leaking fuel injectors can cause a flooding condition.
Fuel leaking from the fuel pump inlet is due to a faulty one-way check valve in the fuel pump.

Caution : The fuel system is under pressure. To avoid fuel spillage and the risk of personal injury or fire, it is necessary to relieve the fuel system pressure before disconnecting the fuel lines.

Caution : Do not pinch or restrict nylon fuel lines to avoid damage that could cause a fuel leak, resulting in possible fire or personal injury.

Fuel Pressure Relief Procedure

Remove the fuel cap.
Remove the fuel pump fuse EF11 from the engine fuse box.
Start the engine and allow the engine to stall.
Crank the engine for an additional 10 seconds.

Fuel System Diagnosis

Step	Action	Value(s)	Yes	No
1	Relieve the fuel system pressure. Install a fuel pressure gauge. Turn the ignition ON. Is the fuel pressure within the values specified and holding steady?	379~393 kPa (55~57 psi)	-	Go to Step 2
2	Inspect the fuel lines for a leak. Is the problem found?	-	Go to Step 3	Go to Step 4
3	Replace the fuel line(s) as needed. Install a fuel pressure gauge. Turn the ignition ON. Is the fuel pressure within the values specified and holding steady?	379~393 kPa (55~57 psi)	System OK	-
4	Remove the fuel pump assembly. With the fuel pump under pressure, inspect the fuel pump coupling hoses for leaking. Is the problem found?	-	Go to Step 5	Go to Step 6
5	Tighten or replace the fuel pump coupling hoses as needed. Install a fuel pressure gauge. Turn the ignition ON. Is the fuel pressure within the values specified and holding steady?	379~393 kPa (55~57 psi)	System OK	-
6	With the fuel system under pressure, inspect the fuel inlet for leaking. Is the problem found?	-	Go to Step 7	Go to Step 8
7	Replace the fuel pump assembly. Install a fuel pressure gauge. Turn the ignition ON. Is the fuel pressure within the values specified and holding steady?	379~393 kPa (55~57 psi)	System OK	-
8	With the fuel system under pressure, inspect the fuel return outlet for leaking. Is the problem found?	-	Go to Step 9	Go to Step 10
9	Replace the fuel pump assembly. Install a fuel pressure gauge. Turn the ignition ON. Is the fuel pressure within the values specified and holding steady?	379~393 kPa (55~57 psi)	System OK	-
10	Remove the fuel rail and the fuel injectors as an assembly. With the fuel system under pressure, inspect all of the fuel injectors for leaking. Is the problem found?	-	Go to Step 11	-
11	Replace the leaking fuel injector(s). Install a fuel pressure gauge. Turn the ignition ON. Is the fuel pressure within the values specified and holding steady?	379~393 kPa (55~57 psi)	System OK	-

Fuel Pump Relay Circuit Check (1.2L DOHC)

Circuit Description

When the ignition switch is turned ON, the Engine Control Module (ECM) will supply battery voltage to activate the fuel pump relay and run the in-tank fuel pump. The fuel pump will operate as long as the engine is cranking or running and the ECM is receiving ignition reference pulses.

If there are no reference pulses, the ECM will shut off the fuel pump within 2 seconds after the ignition switch is turned ON.

Diagnostic Aids

An intermittent problem may be caused by a poor connection, rubbed through wire insulation, or a broken wire inside the insulation.

Test Description

The number(s) below refer to step(s) on the diagnostic table.

This step checks for the ECM providing a ground for the operation of the fuel pump relay.
By confirming that the wiring is OK using Steps 2 through 6, it can be determined that the fuel pump relay is at fault.
After determining that there is no ground being provided by the ECM to the fuel pump relay, the fault is either the ECM or the wiring between the ECM and the fuel pump relay.

Fuel Pump Relay Circuit Check (1.2L DOHC)

Step	Action	Value(s)	Yes	No
1	Turn the ignition OFF for 10 seconds. Turn the ignition ON. Listen for in-tank fuel pump operation. Does the fuel pump operate for the time specified?	2 sec	System OK	Go to Step 2
2	Turn the ignition OFF. Disconnect the fuel pump relay. Connect a test light between the fuel pump relay connector terminal 30 and ground. Turn the ignition ON. Is the test light on?	-	Go to Step 3	Go to Step 8
3	Turn the ignition OFF. Connect a test light between the fuel pump relay connector terminal 85 and battery positive. Turn the ignition ON. With the ignition ON, the test light should light for the time specified. Is the test light on?	2 sec	Go to Step 4	Go to Step 9
4	Turn the ignition OFF. Connect a test light between the fuel pump relay connector terminal 30 and ground. Is the test light on?	-	Go to Step 5	Go to Step 11
5	Check for an open or short to ground in the wire between the fuel pump relay connector terminal 87 and the fuel pump connector terminal 3. Is the problem found?	-	Go to Step 6	Go to Step 7
6	Repair the wire between the fuel pump relay connector terminal 87 and the fuel pump connector terminal 3. Install the fuel pump relay. Turn the ignition OFF for 10 seconds. Turn the ignition ON. Does the fuel pump operate for the time specified?	2 sec	System OK	-
7	Replace the fuel pump relay. Turn the ignition OFF for 10 seconds. Turn the ignition ON. Does the fuel pump operate for the time specified?	2 sec	System OK	-
8	Check for an open wire between the fuel pump relay connector terminal 30 and the battery. Is the problem found?	-	Go to Step 13	-
9	Check for an open wire between the fuel pump relay connector terminal 85 to the engine control module (ECM) connector terminal 6. Is the problem found.	-	Go to Step 10	Go to Step 12
10	Repair the wire between the fuel pump relay connector terminal 85 to the ECM connector terminal 6. Install the fuel pump relay. Turn the ignition OFF for 10 seconds. Turn the ignition ON. Does the fuel pump operate for the time specified?	2 sec	System OK	-
11	Replace the fuse Ef11 or repair the wire between the fuel pump relay connector terminal 30 and the battery. Install the fuel pump relay. Turn the ignition OFF for 10 seconds. Turn the ignition ON. Does the fuel pump operate for the time specified?	2 sec	System OK	-
12	Turn the ignition OFF. Replace the ECM. Turn the ignition ON. Does the fuel pump operate for the time specified?	2 sec	System OK	-
13	Replace the fuse Ef11 or repair the wire between the fuel pump relay connector terminal 30 and the ignition system Install the fuel pump relay. Turn the ignition OFF for 10 seconds. Turn the ignition ON. Does the fuel pump operate for the time specified?	2 sec	System OK	-