2010 Cadillac Truck SRX FWD V6-3.0L Page 2007
* Circuit Testing (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Circuit
Testing/Circuit Testing)
* Connector Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic
Procedures/Connector Repairs/Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (See: Testing and Inspection/Component Tests and General Diagnostics/General
Electrical Diagnostic Procedures/Circuit Testing/Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Wiring
Repairs/Wiring Repairs)
DTC Type Reference
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 Verification
1. Observe the DTC information with a scan tool. DTC P2177 or P2187 should not be set.
瀚慖f there are other DTCs set besides DTC P2177 or P2187 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 BARO 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/Altitude Versus
Barometric Pressure).
瀚慖f the BARO pressure is not within the range specified for your altitude, refer to DTC P2227, P2228, or P2229 (LAU) ( See: P Code
Charts/P2227).
3. Engine at normal operating temperature, observe the Average Total Fuel Trim parameter with a scan tool. The Average Total Fuel Trim
should be between -22 to +23 %.
瀚慖f not within the specified range, verify none of the following conditions exist:
* A mass air flow sensor signal that is skewed-If the Short Term Fuel Trim parameter changes greater than 20 % when the MAF sensor is
disconnected, refer to DTC P0101 (LAU) (See: P Code Charts/P0101)DTC P0101 (LF1) (See: P Code Charts/P0101).
* The air intake system after the MAF sensor for vacuum leaks
* Fuel contamination-Refer to Alcohol/Contaminants-in-Fuel Diagnosis (Special Tool) (See: Powertrain Management/Fuel Delivery and
Air Induction/Fuel/Testing and Inspection/Alcohol/Contaminants-in-Fuel Diagnosis (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).
* Splits, kinks, or improper connections at the vacuum hoses.
* The fuel system is operating lean. Refer to Fuel System Diagnosis (LF1 China) (See: Powertrain Management/Fuel Delivery and Air
Induction/Fuel Pump/Testing and Inspection/Fuel System Diagnosis (China))Fuel System Diagnosis (LF1 Except China) (See:
Powertrain Management/Fuel Delivery and Air Induction/Fuel Pump/Testing and Inspection/Fuel System Diagnosis (Except China))Fuel
System Diagnosis (LAU China) (See: Powertrain Management/Fuel Delivery and Air Induction/Fuel Pump/Testing and Inspection/Fuel
System Diagnosis (China))Fuel System Diagnosis (LAU Except China) (See: Powertrain Management/Fuel Delivery and Air
Induction/Fuel Pump/Testing and Inspection/Fuel System Diagnosis (Except China)).
* Vacuum leaks at the intake manifold or throttle body
* Leaking crankcase ventilation system
* The engine control module grounds for being clean, tight, and in the correct locations
* A high engine oil level condition-A high engine oil level causes oil residue to form on the mass air flow sensor, causing a lean indication.
The MAF sensor does not need to be replaced.
* Vacuum leaks that only affect one bank of the engine-For example, the intake manifold, the injector O-rings.
* Lean injectors-Refer to Fuel Injector Solenoid Coil Test (LAU) (See: Powertrain Management/Fuel Delivery and Air Induction/Fuel
Injector/Testing and Inspection)Fuel Injector Solenoid Coil Test (LF1, LFW) (See: Powertrain Management/Fuel Delivery and Air
Induction/Fuel Injector/Testing and Inspection).
* Missing, restricted, or leaking exhaust components-Refer to Symptoms - Engine Exhaust (See: Engine, Cooling and Exhaust/Exhaust
System/Testing and Inspection/Symptoms - Engine Exhaust).
* The heated oxygen sensor (HO2S) is installed securely and the electrical connector is not contacting the exhaust system.
* 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.
