2010 Cadillac Truck SRX FWD V6-3.0L Page 1117

2010 Cadillac Truck SRX FWD V6-3.0L Page 1117

Control Module References (See: Testing and Inspection/Programming and Relearning) for scan tool information

Special Tools

J 38522 Variable Signal Generator

Circuit/System Verification

1. Verify that DTCs P0685, P0690 or B1380 are not set.

瀚慖f any of the DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle (See: Diagnostic Trouble Code

Descriptions/Diagnostic Trouble Code (DTC) List - Vehicle).

2. Engine running, observe the scan tool MAF Sensor Signal parameter. The reading should be between 1,700-3,800 Hz depending on the

engine coolant temperature (ECT).

3. A wide open throttle (WOT) acceleration from a stop should cause the MAF sensor parameter on the scan tool to increase rapidly. This

increase should be from 2-6 g/s at idle to greater than 180 g/s at the time of the 1-2 shift.

4. 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. Verify that DTCs P0685, P0690 or B1380 are not set.

瀚慖f any of the DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle (See: Diagnostic Trouble Code

Descriptions/Diagnostic Trouble Code (DTC) List - Vehicle).

2. Verify the integrity of the air induction system by inspecting for the following conditions:

* Loose or improper installation

* Water intrusion

3. Ignition OFF, disconnect the harness connector at the B75B MAF/IAT sensor.

4. Remove the fuse that supplies B+ to terminal 52 X1 of the ECM.

5. Ignition OFF and all vehicle systems OFF. It may take up to 2 minutes for all vehicle systems to power down. Test for less than 5 ohm

between the ground circuit terminal B and ground.

瀚慖f greater than the specified range, test the ground circuit for an open/high resistance.

6. Install the fuse that supplies B+ to terminal 52 X1 of the ECM.

7. Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal C and ground.

瀚慖f the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance.

瀚慖f the circuit tests normal and the fuse is open, test all the components connected to the circuit, and repair or replace as necessary.

8. Ignition ON, test for 4.8-5.2 V between the signal circuit terminal A and ground.

瀚慖f less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace

the K20 ECM.

瀚慖f greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM.

9. Ignition OFF, connect the red lead of the J 38522 to the signal circuit terminal A at the B75B MAF/IAT sensor harness connector. Connect

the battery voltage supply to B+, and the black lead to ground.

10. Set the J 38522 signal to 5 V, the Frequency to 5K, and the Duty Cycle to Normal.

11. Engine idling, observe the scan tool MAF Sensor parameter. The scan tool MAF Sensor parameter should be between 4,950-5,050 Hz.

瀚慖f the MAF Sensor parameter is not within the specified range, replace the K20 ECM.

12. If all other circuits test normal, replace the B75B MAF/IAT sensor.

Repair Instructions

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

* Mass Airflow Sensor with Intake Air Temperature Sensor Replacement (LF1) (See: Powertrain Management/Computers and Control

Systems/Air Temperature Sensor ( Ambient / Intake )/Service and Repair)Mass Airflow Sensor with Intake Air Temperature Sensor

Replacement (LAU) (See: Powertrain Management/Computers and Control Systems/Air Temperature Sensor ( Ambient / Intake )/Service

and Repair)

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