2010 Cadillac CTS Sedan AWD V6-3.6L Page 972
Powertrain Diagnostic Trouble Code (DTC) Type Definitions (See: Diagnostic Trouble Code Descriptions/Powertrain Diagnostic Trouble Code
(DTC) Type Definitions)
Scan Tool Reference
Control Module References (See: Testing and Inspection/Programming and Relearning) for scan tool information
Circuit/System Testing
1. Verify none of the following conditions exist:
* The air intake duct system for loose clamps, cracks, or other damage
* The air intake duct system for being collapsed or restricted
* The B75 mass airflow sensor is installed correctly.
* Restricted air filter
* Q38 throttle body for dirt, debris, and coking. Also, throttle body blade or shaft damage. Refer to Throttle Body Inspection and Cleaning
(See: Powertrain Management/Fuel Delivery and Air Induction/Throttle Body/Service and Repair/Procedures) for further diagnosis.
* Splits, kinks, or improper connections at the vacuum hoses
* Missing, restricted, or leaking exhaust components-Refer to Symptoms - Engine Exhaust (See: Engine, Cooling and Exhaust/Exhaust
System/Testing and Inspection/Symptoms - Engine Exhaust).
* Vacuum leaks at the intake manifold and Q38 throttle body.
瀚慖f a condition exists, repair as necessary.
2. Ignition ON, observe the diagnostic trouble code (DTC) information with a scan tool. Verify that DTC P0641, P0651, P0697, or P06A3 is
not set.
瀚慖f any of the above DTCs are set, refer to DTC P0641, P0651, P0697, or P06A3 (ECM, LF1) ( See: P Code Charts/P0641) for further
diagnosis.
3. Determine the current vehicle testing altitude. Compare the MAP Sensor pressure parameter to the reading in the Altitude Versus Barometric
Pressure (See: Powertrain Management/Computers and Control Systems/Specifications) table. The MAP sensor pressure parameter should
be within the specified range indicated in the table.
瀚慖f the MAP sensor pressure is not within the range specified for your altitude, refer to DTC P0106 (w/LF1) (See: P Code Charts/P0106).
4. Engine idling, observe the MAP Sensor kPa parameter. The reading should be between 26-52 kPa (3.8-7.5 psi).
瀚慖f not within the specified range, refer to DTC P0106 (w/LF1) (See: P Code Charts/P0106).
5. Use the scan tool snapshot function to take a snapshot of the engine data list while performing the actions listed below.
1. Engine idling
2. Increase the engine speed slowly to 3,000 RPM and then back to idle.
3. Exit from the scan tool snapshot and review the data.
4. Observe the MAF Sensor g/s parameter frame by frame with a scan tool. The MAF Sensor g/s parameter should change smoothly and
gradually as the engine speed is increased and then returned to idle.
瀚慖f the MAF Sensor g/s parameter does not change smoothly and gradually, refer to DTC P0101 (w/LLT) (See: P Code Charts/P0101
)DTC P0101 (LF1) (See: P Code Charts/P0101) for further diagnosis.
6. If all conditions test normal, test the engine for a mechanical condition. Refer to Symptoms - Engine Mechanical (See: Engine, Cooling and
Exhaust/Engine/Testing and Inspection/Symptom Related Diagnostic Procedures/Symptoms - Engine Mechanical).
Repair Instructions
Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.
* 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 (LLT) (See: Powertrain Management/Fuel Delivery and Air
Induction/Throttle Body/Service and Repair/Removal and Replacement)
* Air Cleaner Element Replacement (LLT) (See: Engine, Cooling and Exhaust/Engine/Tune-up and Engine Performance Checks/Air Cleaner
Housing/Air Filter Element/Service and Repair)Air Cleaner Element Replacement (LSA) (See: Engine, Cooling and
Exhaust/Engine/Tune-up and Engine Performance Checks/Air Cleaner Housing/Air Filter Element/Service and Repair)Air Cleaner Element
Replacement (LF1) (See: Engine, Cooling and Exhaust/Engine/Tune-up and Engine Performance Checks/Air Cleaner Housing/Air Filter
Element/Service and Repair)
