2010 Cadillac Truck SRX AWD V6-2.8L Turbo Page 1853
percent. If the O2S indicate a rich condition, fuel trim values will be below 0 percent. 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
P2178
* Before the ECM can report DTC P2178 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 grams/second.
* The throttle angle is less than 100 percent.
* The engine load is between 17-55 percent.
* The fuel system is in closed loop.
* The engine is not in decel fuel cut-off (DEFCO).
* The long term fuel trim is active.
* The engine coolant temperature (ECT) is greater than 60掳C (140掳F).
* The intake air temperature (IAT) is less than 61掳C (142掳F).
* The evaporative emission (EVAP) canister purge solenoid valve is not enabled.
* The fuel level is greater than 12 percent.
* The amount of air flow into the engine is greater than 7,000 grams.
* DTC P2178 run continuously once the above conditions are met for at least 300 seconds.
P2188
* Before the ECM can report DTC P2188 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 480-1,001 RPM.
* The engine load is between 7-32 percent.
* The MAF is between 1-8 grams per second.
* The fuel system is in closed loop.
* The engine is not in decel fuel cut-off (DEFCO).
* The long term fuel trim is active.
* The engine coolant temperature (ECT) is greater than 60掳C (140掳F).
* The intake air temperature (IAT) is less than 61掳C (142掳F).
* The evaporative emission (EVAP) canister purge solenoid valve is not enabled.
* The fuel level is greater than 12 percent.
* The amount of air flow into the engine is greater than 7,000 grams.
* DTC P2188 run continuously once the above conditions are met.
Conditions for Setting the DTC
P2178
The Total Fuel Trim Avg. is less than -22 percent. The condition exists for 4 seconds or for a cumulative of 30 seconds.
P2188
The Total Fuel Trim Avg. is less than -40 percent. The LT FT Idle/Decel is less than -6 percent. The condition exists for 4 seconds or for a
cumulative of 30 seconds.
Action Taken When the DTC Sets
DTCs P2178 and P2188 are Type B DTCs.
Conditions for Clearing the MIL/DTC
DTCs P2178 and P2188 are Type B DTCs.
Diagnostic Aids
* A fuel system delivery condition causes this DTC to set. Thoroughly inspect all items that cause a rich condition. 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)).
