2010 Cadillac CTS Sedan AWD V6-3.6L Page 1918
* Any of the conditions above exist, then a 5 second delay for MIL ON.
Action Taken When the DTC Sets
DTC P2176 is a Type A DTC.
Conditions for Clearing the DTC
DTC P2176 is a Type A DTC.
Circuit/System Verification
1. Ignition ON, rapidly depress the accelerator pedal from the rest position to the wide open throttle position (WOT) and release the pedal.
Repeat the procedure several times. Observe the DTC information with a scan tool. Verify that DTC P0121, P0122, P0123, P0221, P0222,
P0223, P0638, or P2101 do not set.
瀚慖f a DTC is set, refer to Diagnostic Trouble Code (DTC) List - Vehicle (See: Diagnostic Trouble Code Descriptions/Diagnostic Trouble
Code (DTC) List - Vehicle)DTC P0121-P0123 or P0221-P0223 (Without LF1) (See: P Code Charts/P0121) for further diagnosis.
2. DTC P2176 is an informational DTC. Perform the throttle learn procedure, refer to Throttle/Idle Learn (LF1) (See: Engine, Cooling and
Exhaust/Engine/Tune-up and Engine Performance Checks/Idle Speed/Testing and Inspection)Throttle/Idle Learn (Without LF1) (See:
Engine, Cooling and Exhaust/Engine/Tune-up and Engine Performance Checks/Idle Speed/Testing and Inspection).
瀚慖f DTC P2176 resets after performing the throttle learn procedure, replace the throttle body.
3. 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.
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)
P2177
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.
DTC Descriptors
DTC P2177
- Fuel Trim System Lean at Cruise or Acceleration Bank 1
DTC P2179
- Fuel Trim System Lean at Cruise or Acceleration Bank 2
DTC P2187
- Fuel Trim System Lean at Idle Bank 1
DTC P2189
- Fuel Trim System Lean at Idle Bank 2
Circuit Description
The fuel trim control system monitors the range of the air/fuel ratio in order to maintain the desired ratio for optimum emissions performance. The
system performs tests during certain operating conditions to detect unmetered air or unmetered fuel. The fuel trim control system operation can be
observed by monitoring the scan tool Short Term and Long Term Fuel Trim parameters.
