2010 Cadillac Truck SRX AWD V6-2.8L Turbo Page 1043

2010 Cadillac Truck SRX AWD V6-2.8L Turbo Page 1043

* An air flow restriction

* Any vacuum leaks

* Water intrusion

* In cold climates, inspect for any snow or ice buildup

* Inspect the B75 MAF sensor element for contamination.

2. Ignition OFF, disconnect the harness connector at the B75 MAF sensor.

3. Remove the fuse that supplies B+ to terminal 56 X2 of the ECM.

4. 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 2 and ground.

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

5. Install fuse that supplies B+ to terminal 56 X2 of the ECM.

Caution: Do NOT use the low reference circuit in the component harness connector for this test. Damage to the control module may occur

due to excessive current draw.

6. Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal 4 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. If the circuit tests normal and

the ignition circuit fuse is open, test all the components connected to the ignition circuit and replace as necessary.

7. Ignition ON, test for 4.8-5.2 V between the signal circuit terminal 5 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.

8. Ignition OFF, connect the red lead of the J 38522 to the signal circuit terminal 5 at the B75 MAF sensor harness connector. Connect the

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

9. Set the J 38522 Signal switch to 5 V, the Frequency switch to 5K, and the Duty Cycle switch to Normal.

10. Engine idling, observe the scan tool MAF Sensor Hz parameter. The 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.

11. If all circuits test normal, test or replace the B75 MAF sensor.

Repair Instructions

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

* Engine Coolant Temperature Sensor Replacement (LF1) (See: Engine, Cooling and Exhaust/Cooling System/Engine - Coolant Temperature

Sensor/Switch/Coolant Temperature Sensor/Switch (For Computer)/Service and Repair)Engine Coolant Temperature Sensor Replacement

(LAU) (See: Engine, Cooling and Exhaust/Cooling System/Engine - Coolant Temperature Sensor/Switch/Coolant Temperature

Sensor/Switch (For Computer)/Service and Repair)

* 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

P0102

DTC P0100-P0103 (LAU)

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 P0100

- Mass Air Flow (MAF) Sensor Circuit