2010 Cadillac CTS Sedan AWD V6-3.6L Page 1074
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 (LLT) (See: Diagrams/Electrical Diagrams/Powertrain Management/System Diagram)Engine Controls Schematics
(LF1) (See: Diagrams/Electrical Diagrams/Powertrain Management/System Diagram)
Connector End View Reference
Component Connector End Views (See: Diagrams/Connector Views)
Description and Operation
* Electronic Ignition System Description (See: Powertrain Management/Computers and Control Systems/Description and
Operation/Electronic Ignition System Description)
* Engine Control Module Description (See: Powertrain Management/Computers and Control Systems/Description and Operation/Engine
Control Module Description)
Electrical Information Reference
* Circuit Testing (See: Testing and Inspection/Component Tests and General Diagnostics/Circuit Testing/Circuit Testing)
* Connector Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/Connector Repairs/Connector Repairs)
* Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/Wiring Repairs/Wiring Repairs)
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions (See: Diagnostic Trouble Code Descriptions/Powertrain Diagnostic Trouble Code
(DTC) Type Definitions)
Scan Tool Reference
Engine Control Module Scan Tool Information (V6) (See: Powertrain Management/Computers and Control Systems/Testing and Inspection/Scan
Tool Testing and Procedures)Engine Control Module Scan Tool Information (V8) (See: Powertrain Management/Computers and Control
Systems/Testing and Inspection/Scan Tool Testing and Procedures)Engine Control Module Scan Tool Information (LF1) (See: Powertrain
Management/Computers and Control Systems/Testing and Inspection/Scan Tool Testing and Procedures) 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
瀚慐ach 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.
1. Ignition OFF, disconnect the harness connector at the appropriate T8 ignition coil.
2. Ignition ON, verify that a test lamp illuminates between the ignition voltage circuit terminal D and ground of each T8 ignition coil.
瀚慖f the test lamp does not illuminate, test the circuit for a short to ground or an open/high resistance.
瀚慖f 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.
3. Ignition OFF, disconnect the K20 ECM harness connector X1.
4. 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.
