2010 Cadillac CTS Sedan AWD V6-3.6L Page 1922
* 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 engine coolant temperature (ECT) is warmer than 60掳C (140掳F).
* The intake air temperature (IAT) is colder than 61掳C (142掳F).
* The calculated amount of fuel metered into the engine is greater than 700 g.
* DTCs P2188 and P2190 run continuously when the above conditions are met for approximately 300 s, after Closed Loop fuel control is
enabled.
Conditions for Setting the DTC
P2178 or P2180
The Long Term Fuel Trim Cruise/Accel is less than -22 % for 4 s or for a cumulative of 30 s.
P2188 or P2190
The Long Term Fuel Trim Idle/Decel is less than -6 % for 4 s or for a cumulative of 30 s.
Action Taken When the DTC Sets
DTCs P2178, P2180, P2188, and P2190 are Type B DTCs.
Conditions for Clearing the MIL/DTC
DTCs P2178, P2180, P2188, and P2190 are Type B DTCs.
Diagnostic Aids
* An HO2S will not cause this DTC to set without the occurrence of circuit related HO2S DTCs. Do not replace an HO2S to address this DTC.
* Observing the LT FT Bn 1 and Bn 2 parameters, while driving the vehicle can determine whether the rich condition is effecting only one
bank , or is common to both banks of the engine.
* A fuel system delivery condition causes this DTC to set. Thoroughly inspect all items that cause a rich condition. Refer to Fuel System
Diagnosis (See: Powertrain Management/Computers and Control Systems/Testing and Inspection/Component Tests and General
Diagnostics/Fuel System Diagnosis).
* Review the Freeze Frame/Failure Records with a scan tool.
Reference Information
Schematic Reference
Engine Controls Schematics (LLT) (See: Diagrams/Electrical Diagrams/Powertrain Management/System Diagram)Engine Controls Schematics
(LF1) (See: Diagrams/Electrical Diagrams/Powertrain Management/System Diagram)
Connector End View Reference
Component Connector End Views (See: Diagrams/Connector Views)
Electrical Information Reference
* Circuit Testing (See: Testing and Inspection/Component Tests and General Diagnostics/Circuit Testing/Circuit Testing)
* Connector Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/Connector Repairs/Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (See: Testing and Inspection/Component Tests and General Diagnostics/Circuit
Testing/Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/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 P2178, P2180, P2188, or P2190 should not be set.
瀚慖f any other DTC is set, 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 barometric pressure (BARO) sensor 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
