2010 Cadillac Truck SRX FWD V6-3.0L Page 1876
parameters display OK.
5. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the
conditions that you observed from the Freeze Frame/Failure Records data.
Circuit/System Testing
1. Ignition OFF, disconnect the appropriate multi-way harness connector X198 or X199, at the rear of the intake manifold.
2. Ignition ON, observe the appropriate scan tool Cylinder 1-6 Injector Control Circuit Status. The parameter should display Open.
瀚慖f not the specified value, test the appropriate high voltage supply circuit, ECM side, for a short to ground or the appropriate high voltage
control circuit, ECM side, for a short to voltage. If the circuits test normal, replace the K20 ECM.
3. Ignition ON, connect a test lamp between the appropriate high voltage supply circuit and the high voltage control circuit. The Injector
Control Circuit Status should transition from Open to OK.
瀚慖f not the specified value, test for the following conditions in the ECM side of the harness:
* 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
* Fuel Injector Solenoid Coil Test (LAU) (See: Powertrain Management/Fuel Delivery and Air Induction/Fuel Injector/Testing and Inspection
)Fuel Injector Solenoid Coil Test (LF1, LFW) (See: Powertrain Management/Fuel Delivery and Air Induction/Fuel Injector/Testing and
Inspection)
* Fuel Injector Balance Test (LAU) (See: Powertrain Management/Computers and Control Systems/Testing and Inspection/Component Tests
and General Diagnostics/Fuel Injector Balance Test)Fuel Injector Balance Test (LF1, LFW) (See: Powertrain Management/Computers and
Control Systems/Testing and Inspection/Component Tests and General Diagnostics/Fuel Injector Balance Test)
Repair Instructions
Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.
* Fuel Injection Fuel Rail Assembly Replacement - Bank 1 (LF1) (See: Powertrain Management/Fuel Delivery and Air Induction/Fuel
Rail/Service and Repair/Fuel Injection Fuel Rail Assembly Replacement - Bank 1)
* Fuel Injection Fuel Rail Assembly Replacement - Bank 2 (LF1) (See: Powertrain Management/Fuel Delivery and Air Induction/Fuel
Rail/Service and Repair/Fuel Injection Fuel Rail Assembly Replacement - Bank 2)
* 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 (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.
