2010 Cadillac CTS Sedan AWD V6-3.6L Page 1931
Systems/Testing and Inspection/Component Tests and General Diagnostics/Fuel System Diagnosis).
* 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 (MAF) 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 (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).
* 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.
P2188
DTC P2178, P2180, P2188, or P2190 (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 P2178
- Fuel Trim System Rich at Cruise or Acceleration Bank 1
DTC P2180
- Fuel Trim System Rich at Cruise or Acceleration Bank 2
DTC P2188
- Fuel Trim System Rich at Idle Bank 1
DTC P2190
- Fuel Trim System Rich 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.
Conditions for Running the DTC
P2178 or P2180
* Before the ECM can report DTC P2178 or P2180, failed, DTCs P000A, P000B, P000C, P000D, P0008, P0009, P0010, P0011, P0013,
P0014, P0016, P0017, P0018, P0019, P0020, P0021, P0023, P0024, P0101, P0121, P0122, P0123, P0133, P0153, 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, P2095 P2146, P2149, P2152, P2155, P216A, and P216D must run and pass.
* The engine speed is between 1,200-3,400 RPM.
* The engine load is between 13-40 %.
* The throttle angle is less than 100 %.
* The cold start fuel control is not active.
* The Closed Loop fuel control is enabled.
* The engine is not in decel fuel cut-off.
* The intake air temperature (IAT) is colder than 60掳C (140掳F).
* The calculated amount of fuel metered into the engine is greater than 700 g.
