2010 Cadillac CTS Sedan AWD V6-3.0L Page 1755
* An open/high resistance in the high voltage supply circuit
* An open/high resistance in the high voltage control circuit
* A short to ground in the high voltage control circuit
* A short to voltage in the high voltage supply circuit
瀚慖f the circuits test normal, replace the K20 ECM.
Note: Testing for the following steps is performed on the fuel injector side of the multi-way harness connector. It may be necessary to
remove the intake manifold to isolate the condition.
4. Ignition OFF, measure the resistance between the appropriate high voltage supply circuit and ground. The DMM should display OL ohm.
瀚慖f less than the specified range, test the high voltage supply circuit and the high voltage control circuit for a short to ground. If the
circuits/connections test normal, test or replace the appropriate Q17 fuel injector(s).
5. Test for 2-3 ohm between the appropriate high voltage supply circuit and high voltage control circuit.
瀚慖f less than the specified range, test for a short between the high voltage supply circuit and high voltage control circuit. If the
circuits/connections test normal, test or replace the appropriate Q17 fuel injector(s).
瀚慖f greater than the specified range, test the high voltage supply circuit and high voltage control circuit for an open/high resistance. If the
circuits/connections test normal, test or replace the appropriate Q17 fuel injector.
Component Testing
Note: The DMM and test leads must be calibrated to 0 ohm in order to prevent misdiagnosis.
1. Remove the intake manifold and disconnect the appropriate Q17 fuel injector.
2. Test for 1.9-2.3 ohm at 20掳C (68掳F) between the high voltage supply circuit terminal 2 and the high voltage control circuit terminal 1 at the
Q17 fuel injector.
瀚慖f not within the specified range, replace the Q17 fuel injector.
3. Measure the resistance between each terminal at the Q17 fuel injector and the Q17 fuel injector housing/case. The DMM should display OL
ohm.
瀚慖f less than the specified value, replace the Q17 fuel injector.
Repair Instructions
Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.
* Fuel Injector Replacement (See: Powertrain Management/Fuel Delivery and Air Induction/Fuel Injector/Service and Repair/Fuel Injector
Replacement)
* Control Module References (See: Testing and Inspection/Programming and Relearning) for ECM replacement, setup, and programming
P1249
DTC P1248, P1249, P124A, P124B, P124C, or P124D (w/LF1)
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 P1248
- Cylinder 1 Injector High Control Circuit Shorted to Control Circuit
DTC P1249
- Cylinder 2 Injector High Control Circuit Shorted to Control Circuit
DTC P124A
- Cylinder 3 Injector High Control Circuit Shorted to Control Circuit
