2010 Cadillac Truck SRX AWD V6-3.0L Page 2005

2010 Cadillac Truck SRX AWD V6-3.0L Page 2005

Engine Performance Checks/Air Cleaner Housing/Air Filter Element/Service and Repair)Air Cleaner Element Replacement (LAU) (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.

* Excessive fuel in the crankcase-Change the oil as necessary.

* 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).

* The engine control module grounds for being clean, tight, and in the correct locations

* Rich 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).

* 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.

P2187

DTC P2177 or P2187

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 P2177

- Fuel Trim System Lean at Cruise or Acceleration

DTC P2187

- Fuel Trim System Lean at Idle

Circuit Description

The engine control module (ECM) controls the air/fuel metering system in order to provide the best possible combination of driveability, fuel

economy, and emission control. Fuel delivery is controlled differently during Open and Closed Loop. During Open Loop, the ECM determines fuel

delivery based on sensor signals without heated oxygen sensor (HO2S) input. During Closed Loop, the HO2S inputs are added and used by the

ECM to calculate short and long term fuel delivery adjustments. If the HO2S indicate a lean condition, fuel trim values will be above 0 %. If the

HO2S indicate a rich condition, fuel trim values will be below 0 %. Short term fuel trim values change rapidly in response to the HO2S signals.

Long term fuel trim makes coarse adjustments in order to maintain an air/fuel ratio of 14.7:1.

Conditions for Running the DTC

P2177

* Before the ECM can report DTC P2177 failed, DTCs P0008, P0009, P0010, P0011, P0013, P0014, P0016, P0017, P0018, P0019, P0020,

P0021, P0023, P0024, P0101, P0121, P0122, P0123, P0133, P0201, P0202, P0203, P0204, P0205, P0206, P0221, P0222, P0223, P0261,

P0262, P0264, P0265, P0267, P0268, P0270, P0271, P0273, P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0335, P0336, P0338,

P0443, P0458, P0459, P0461, P0462, P0463, P2068 P2088, P2089, P2090, P2091, P2092, P2093, P2094, and P2095 must run and pass.

* The engine speed is between 1,200-3,400 RPM.

* The mass air flow is between 7-83 g/s.

* The throttle angle is less than 100 %.

* The engine load is between 17-55 %.

* The fuel system is in Closed Loop.

* The engine is not in decel fuel cut-off.