2010 Cadillac CTS Sedan AWD V6-3.6L Page 1933
Control Module References (See: Testing and Inspection/Programming and Relearning) for scan tool information
Circuit/System Verification
1. Observe the DTC information with a scan tool. DTC P2178, P2180, P2188, or P2190 should not be set.
瀚慖f any other DTC is set, refer to Diagnostic Trouble Code (DTC) List - Vehicle (See: Diagnostic Trouble Code Descriptions/Diagnostic
Trouble Code (DTC) List - Vehicle) to diagnosis the applicable DTC.
2. Ignition ON, observe the barometric pressure (BARO) sensor pressure parameter and compare the reading on the scan tool to the barometric
pressure table. Refer to Altitude Versus Barometric Pressure (See: Powertrain Management/Computers and Control Systems/Specifications
).
瀚慖f the BARO sensor pressure is not within the range specified for your altitude, refer to DTC P2227, P2228, or P2229 (LLT) ( See: P
Code Charts/P2227).
3. Engine at normal operating temperature, observe the scan tool Long Term Fuel Trim parameters. The LT FT Cruise/Accel parameters should
be greater than -23 %. The LT FT Idle/Decel parameters should be greater than -7 %.
瀚慖f not within the specified range, inspect for the following conditions:
* A mass air flow (MAF) sensor signal that is skewed. If the Short Term FT parameters for both banks changes greater than 20 % when the
MAF sensor is disconnected, refer to DTC P0101 (w/LLT) (See: P Code Charts/P0101)DTC P0101 (LF1) (See: P Code Charts/P0101).
* A collapsed air intake duct
* A restricted air filter element-Refer to 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).
* The MAF sensor for foreign objects-Refer to 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).
* Excessive fuel in the crankcase-Change the oil as necessary.
* Fuel contamination-Refer to Alcohol/Contaminants-in-Fuel Diagnosis (with Special Tool) (See: Powertrain Management/Computers
and Control Systems/Testing and Inspection/Component Tests and General Diagnostics/Alcohol/Contaminants-in-Fuel Diagnosis (with
Special Tool))Alcohol/Contaminants-in-Fuel Diagnosis (without Special Tool) (See: Powertrain Management/Computers and Control
Systems/Testing and Inspection/Component Tests and General Diagnostics/Alcohol/Contaminants-in-Fuel Diagnosis (without Special
Tool)) and Fuel System Cleaning (See: Powertrain Management/Fuel Delivery and Air Induction/Service and Repair).
* The engine control module grounds for being clean, tight, and in the correct locations
* Rich injectors-Refer to Fuel Injector Solenoid Coil Test (w/LLT) (See: Powertrain Management/Computers and Control
Systems/Testing and Inspection/Component Tests and General Diagnostics/Fuel Injector Solenoid Coil Test)Fuel Injector Solenoid Coil
Test (w/LF1) (See: Powertrain Management/Fuel Delivery and Air Induction/Fuel Injector/Testing and Inspection).
* Restricted exhaust system-Refer to Symptoms - Engine Exhaust (See: Engine, Cooling and Exhaust/Exhaust System/Testing and
Inspection/Symptoms - Engine Exhaust).
* An engine mechanical condition-Refer to Symptoms - Engine Mechanical (See: Engine, Cooling and Exhaust/Engine/Testing and
Inspection/Symptom Related Diagnostic Procedures/Symptoms - Engine Mechanical).
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.
Repair Instructions
Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.
P2189
DTC P2177, P2179, P2187, or P2189 (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.
