Captiva |
||||||||
|
|
• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
• | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
• | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
---|---|---|---|---|
IAT Sensor Signal | P0112, P0114 | P0111, P0113, P0114 | P0113*, P0114 | P0111 |
Low Reference | - | P0111, P0113, P0114 | P0113*, P0114 | P0111 |
*Internal ECM or sensor damage may occur if the circuit is shorted to B+. |
Circuit | Short to Ground | Open or High Resistance | Short to Voltage |
---|---|---|---|
Operating Conditions: Engine Running Parameter Normal Range: Varies with ambient temperature | |||
IAT Sensor Signal | 150°C (302°F) | -40°C (-40°F) | -40°C (-40°F)* |
Low Reference | - | -40°C (-40°F) | -40°C (-40°F)* |
*Internal ECM or sensor damage may occur if the circuit is shorted to B+ |
Circuit | Short to Ground | Open or High Resistance | Short to Voltage |
---|---|---|---|
Operating Conditions: Engine Running Parameter Normal Range: Varies with coolant temperature | |||
ECT Sensor Signal | 150°C (302°F) | -40°C (-40°F) | -40°C (-40°F)* |
Low Reference | - | -40°C (-40°F) | -40°C (-40°F)* |
*Internal ECM or sensor damage may occur if the circuit is shorted to B+ |
The intake air temperature (IAT) sensor is integrated with the mass air flow (MAF) sensor. It is a variable resistor that measures the temperature of the air entering the engine. The IAT sensor has a signal circuit and a low reference circuit. The engine control module (ECM) supplies 5 volts to the IAT signal circuit and a ground for the IAT low reference circuit.
IAT | IAT Resistance | IAT Signal Voltage |
---|---|---|
Cold | High | High |
Warm | Low | Low |
• | DTCs P0112, P0113, P0117, P0118 are not set. |
• | The vehicle has been OFF at least 8 hours. |
• | The ignition is ON. |
• | This DTC runs once per ignition cycle when the enabling conditions are met. |
The ECM determines the absolute difference between IAT start-up temperature and the ECT start-up temperature is greater than 20°C (36°F).
DTC P0111 is a Type B DTC.
DTC P0111 is a Type B DTC.
• | An IAT sensor that is skewed, due to more resistance than is normal, can widen the spread between the 2 sensors and cause this DTC to set. Measure and record the resistance of the IAT sensor at various ambient temperatures, and then compare those measurements to the Temperature vs. Resistance Table. Refer to Temperature Versus Resistance - Intake Air Temperature Sensor . |
• | A slight to moderate resistance in the IAT sensor signal circuit or low reference circuit will increase the range between these two sensors. This condition results in a greater voltage on the IAT sensor signal circuit, which is interpreted by the ECM as a colder IAT. |
• | Inspect the mass air flow/inlet air temperature sensor terminals for corrosion. |
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Control Module References for scan tool information
Note: Perform Step 1 of this verification procedure only if the ignition has been OFF for 8 hours or more.
• | Start-Up IAT |
• | Start-Up ECT |
⇒ | If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the K20 ECM. |
⇒ | If warmer than the specified range, test the signal circuit for a short to ground. If the circuit tests normal, replace the K20 ECM. |
Note: If the fuse in the jumper wire opens, the signal circuit is shorted to a voltage and the ECM or the sensor may be damaged.
⇒ | If colder than the specified range, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the K20 ECM. |
Note: A thermometer can be used to test the sensor off the vehicle.
⇒ | If not within the specified range, B75B mass air flow/inlet air temperature sensor. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for ECM replacement, setup, and programming |
© Copyright Chevrolet. All rights reserved |