2010 Cadillac CTS Sedan AWD V6-3.6L Page 1116
1. Ignition OFF, disconnect the harness connector at the G18 high pressure fuel pump.
Note: The DMM and test leads must be calibrated to 0 ohm in order to prevent misdiagnosis.
2. Test for 9-11 ohm at 25掳C (77掳F) between the low control circuit terminal 1 and the high control circuit terminal 2.
瀚慖f not within the specified range, replace the G18 high pressure fuel pump.
3. Measure the resistance between each terminal and the high pressure fuel pump housing. The DMM should display OL.
瀚慖f less than the specified value, replace the G18 high pressure fuel pump.
4. Ignition OFF, verify that a test lamp does not illuminate between B+ and the low control circuit terminal 1.
瀚慖f the test lamp illuminates, test the low control circuit for a short to ground. If the circuit tests normal, replace the K20 ECM.
5. Ignition ON, verify that a test lamp does not illuminate between ground and the high control circuit terminal 2.
瀚慖f the test lamp illuminates, test the high control circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM.
6. Ignition ON, command the Fuel Pressure Regulator ON with a scan too. Verify that the test lamp illuminates.
瀚慖f the test lamp does not illuminate, test the high control circuit for a short to ground or an open/high resistance. If the circuit tests normal,
replace the K20 ECM.
7. Ignition OFF, connect a test lamp between the low control circuit terminal 1 and B+.
8. Ignition ON, command the Fuel Pressure Regulator ON with a scan tool. Verify that the test lamp illuminates.
瀚慖f the test lamp does not illuminate, test the low control circuit for a short to voltage or an open/high resistance. If the circuit tests normal,
replace the K20 ECM.
9. If all circuits and the high pressure fuel pump test normal, replace the K20 ECM.
Repair Instructions
Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.
* Fuel Pump Replacement (See: Powertrain Management/Fuel Delivery and Air Induction/Fuel Pump/Service and Repair)
* Control Module References (See: Testing and Inspection/Programming and Relearning) for engine control module replacement, setup, and
programming
P167D
DTC P0601-P0604, P0606, P167D, or P2610 (ECM, LLT)
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic System
Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Strategy Based Diagnosis) for an
overview of the diagnostic approach.
* Diagnostic Procedure Instructions (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic Procedure
Instructions) provides an overview of each diagnostic category.
DTC Descriptors
DTC P0601
- Control Module Read Only Memory Performance
DTC P0602
- Control Module Not Programmed
DTC P0603
- Control Module Long Term Memory Reset
DTC P0604
- Control Module Random Access Memory Performance
