2010 Cadillac CTS Sedan AWD V6-3.6L Page 997
Circuit/System Testing
1. Verify that DTCs P0685, P0689, P0690 or B1380 are not set.
瀚慖f any of the DTCs are set, refer to Powertrain Diagnostic Trouble Code (DTC) Type Definitions (See: Diagnostic Trouble Code
Descriptions/Powertrain Diagnostic Trouble Code (DTC) Type Definitions).
2. Ignition OFF, disconnect the harness connector at the B75B MAF/IAT sensor.
3. Ignition OFF, test for less than 5 ohm between the ground circuit terminal C and the battery ground.
瀚慖f greater than the specified range, test the ground circuit for an open/high resistance.
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.
4. Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal B 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.
5. Test for 4.8-5.2 V between the signal circuit terminal A and the ground circuit terminal C.
瀚慖f less than the specified range, test the signal circuit for an open/high resistance or a short to ground. If the circuit/connections test
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/connections test normal, replace the K20
ECM.
6. 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 ground the black lead.
7. Set the J 38522 Signal switch to 5 V, the Frequency switch to 5K, and the Duty Cycle switch to Normal.
8. Ignition ON, observe the scan tool MAF Sensor frequency parameter. The parameter should be between 4,950-5,025 Hz.
瀚慖f the parameter is not within the specified range, replace the K20 ECM.
9. If all circuits/connections 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 (LLT) (See: Powertrain Management/Computers and Control
Systems/Air Temperature Sensor ( Ambient / Intake )/Service and Repair)Mass Airflow Sensor with Intake Air Temperature Sensor
Replacement (LSA) (See: Powertrain Management/Computers and Control Systems/Air Temperature Sensor ( Ambient / Intake )/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)
* Control Module References (See: Testing and Inspection/Programming and Relearning) for engine control module replacement, setup, and
programming
P0101
DTC P0101 (w/LLT)
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 P0101
- Mass Air Flow (MAF) Sensor Circuit Performance
Diagnostic Fault Information
