Service Information

Captiva

DTC P135A or P135B - LF1, LFW or LFX

Diagnostic Instructions

•	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.

DTC Descriptors

DTC P135A: Ignition Coil Supply Voltage Circuit Bank 1

DTC P135B: Ignition Coil Supply Voltage Circuit Bank 2

Diagnostic Fault Information

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
Ignition Coil Supply Voltage Bank 1	P0201, P0203, P0205, P0300, P0351, P0353, P0355, P135A	P0201, P0203, P0205, P0300, P0351, P0353, P0355, P135A	-	-
Ignition Coil Supply Voltage Bank 2	P0202, P0204, P0206, P0300, P0352, P0354, P0356, P135B	P0202, P0204, P0206, P0300, P0352, P0354, P0356, P135B	-	-

The ignition system on this engine uses an individual module/coil for each cylinder. The engine control module (ECM) monitors the ignition voltage from the fuse of each bank of coils to the ECM. The ECM uses this information to determine if the misfire is ignition coil voltage related.

Conditions for Running the DTC

•	The ignition is ON.

•	The ignition module supply voltage is less than 2.5 V.

•	The DTCs run continuously when the above condition is met.

Conditions for Setting the DTC

The ECM detects a fault in an ignition coil control circuit for 50 out of 63 samples. Each sample runs on a 6.25 ms loop.

Action Taken When the DTC Sets

DTCs P135A and P135B are Type A DTCs.

Conditions for Clearing the DTC

DTCs P135A and P135B are Type A DTCs.

Reference Information

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

•	Electronic Ignition System Description

•	Engine Control Module Description

Electrical Information Reference

•	Circuit Testing

•	Connector Repairs

•	Wiring Repairs

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Engine Control Module Scan Tool Information : LNQ → LE5 w/GDS → LF1 w/GDS for scan tool information

Circuit/System Verification

With the ignition ON, observe the following scan tool parameters for each cylinder:

•	Ignition Coil Supply Voltage Bank 1

•	Ignition Coil Supply Voltage Bank 2

⇒	Each parameter should display ON.

Circuit/System Testing

Note: The ignition circuit supplies voltage to other components. Make sure you test all circuits for a short to ground or test all components for being shorted that share the ignition circuit.

Ignition OFF, disconnect the harness connector at the appropriate T8 ignition coil.
Ignition ON, verify that a test lamp illuminates between the ignition voltage circuit terminal D and ground of each T8 ignition coil.

⇒	If the test lamp does not illuminate, test the circuit for a short to ground or an open/high resistance.

⇒	If the circuit tests normal, with the ignition OFF, disconnect the harness connector at each T8 ignition coil and monitor the fuse while individually connecting each T8 ignition coil. If the fuse opens, replace the appropriate T8 ignition coil.

Ignition OFF, disconnect the K20 ECM harness connector X1.
Ignition ON, connect a test lamp between the following ignition voltage circuits and ground:

•

X1 67

•

X1 62

The test lamp should illuminate on each circuit.

⇒	If the test lamp does not illuminate, test the ignition circuit for an open/high resistance.

If all circuits/connections test normal, replace the K20 ECM.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

•	T8 Ignition Coil Replacement - Bank 1

•	T8 Ignition Coil Replacement - Bank 2

•	Control Module References for K20 ECM replacement, setup, and programming