2010 Cadillac Truck SRX FWD V6-3.0L Page 1887

2010 Cadillac Truck SRX FWD V6-3.0L Page 1887

Turn OFF the ignition before inserting fingers into the throttle bore. Unexpected movement of the throttle blade could cause personal injury.

1. Ignition OFF, verify the following conditions do not exist with the Q38 throttle body assembly:

* A throttle blade that is not in the rest position

* A throttle blade that is binding open or closed

* A throttle blade that is free to move open or closed without spring pressure

瀚慖f a condition is found, replace the Q38 throttle body assembly.

Note: Disconnecting the throttle body harness connector may cause additional DTCs to set.

2. Ignition OFF, disconnect the harness connector at the Q38 throttle body assembly.

3. Ignition ON, verify that a test lamp does not illuminate between each motor control circuit listed below and ground.

* Motor control circuit terminal A

* Motor control circuit terminal B

瀚慖f test lamp illuminates, test the motor control circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM.

4. Ignition ON, verify that a test lamp does not illuminate between each motor control circuit listed below and B+.

* Motor control circuit terminal A

* Motor control circuit terminal B

瀚慖f the test lamp illuminates, test the motor control circuit for a short to ground. If the circuit tests normal, replace the K20 ECM.

5. Ignition OFF, set the DMM to the 40 V scale, select the Min/Max Recording Mode, and set the Peak Min/Max response time to 1 ms.

Note:

* The DMM Min/Max Recording Mode and the response time of 1 ms must be reset after testing each circuit.

* The ignition must be OFF and the ECM completely powered down before testing each circuit.

6. Ignition OFF, measure the voltage using the DMM Min/Max Recording Mode function on each circuit listed below as the ignition is turned

ON. The Max voltage should be within 1 V of B+.

* Motor control circuit terminal A

* Motor control circuit terminal B

瀚慖f not within the specified range, test the circuit for an open/high resistance. If the circuit tests normal, replace the K20 ECM.

7. If all circuits and connections test normal, replace the Q38 throttle body assembly.

Repair Instructions

Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the repair.

* Throttle Body Assembly Replacement (LF1) (See: Powertrain Management/Fuel Delivery and Air Induction/Throttle Body/Service and

Repair/Removal and Replacement)Throttle Body Assembly Replacement (LAU) (See: Powertrain Management/Fuel Delivery and Air

Induction/Throttle Body/Service and Repair/Removal and Replacement)

* Control Module References (See: Testing and Inspection/Programming and Relearning) for ECM replacement, programming, and setup

P1551

DTC P1551

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 Descriptor

DTC P1551

- Throttle Valve Rest Position Not Reached During Learn