2010 Cadillac Truck Escalade/ESV RWD V8-6.2L Page 1746
J 38522 Variable Signal Generator
Circuit/System Verification
* Engine idling, observe the scan tool MAF Sensor parameter. The reading should be between 2,000-3,900 Hz, depending on the engine
coolant temperature (ECT).
* 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 4-9 g/s at idle to greater than 180 g/s at the time of the 1-2 shift.
* 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 harness connector at the MAF/IAT sensor.
2. Ignition OFF, all vehicle systems OFF, this may take up to 2 min, test for less than 5 ohm between the ground circuit terminal E and ground.
瀚慖f greater than the specified range, test the ground circuit for an open/high resistance.
3. Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal D 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.
4. Ignition ON, test for 4.8-5.2 V between the MAF signal circuit terminal C and ground.
瀚慖f less than the specified range, test the MAF signal circuit for a short to ground or an open/high resistance. If the circuit tests normal,
replace the ECM.
瀚慖f greater than the specified range, test the MAF signal circuit for a short to voltage. If the circuit tests normal, replace the ECM.
5. Ignition OFF, connect the red lead of the J 38522 to the MAF signal circuit terminal C at the MAF/IAT sensor harness connector. Connect
the battery voltage supply to B+, and the black lead to ground.
6. Set the J 38522 signal to 5 V, the Frequency to 5K, and the Duty Cycle to Normal.
7. Engine idling, observe the scan tool MAF Sensor parameter. The reading should be between 4,950-5,050 Hz.
瀚慖f not within the specified range, replace the ECM.
8. If all circuits test normal, replace the 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 (See: Powertrain Management/Computers and Control Systems/Air
Flow Meter/Sensor/Service and Repair)
* Control Module References (See: Testing and Inspection/Programming and Relearning) for ECM replacement, setup and programming
P0103
DTC P0102 or P0103
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 P0102
- Mass Air Flow (MAF) Sensor Circuit Low Frequency
DTC P0103
- Mass Air Flow (MAF) Sensor Circuit High Frequency
Diagnostic Fault Information
