2010 Cadillac CTS Sedan AWD V6-3.0L Page 1920
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. Ignition ON, observe the DTC information with a scan tool. Verify that DTC P0641 is not set.
瀚慖f a DTC is set, refer to DTC P0641, P0651, P0697, or P06A3 (ECM, LF1) (See: P Code Charts/P0641) for further diagnosis.
2. Ignition ON, observe the scan tool BARO parameter. Compare the parameter to the Altitude Versus Barometric Pressure (See: Powertrain
Management/Computers and Control Systems/Specifications) table. The BARO parameter should be within the specified range indicated in
the table.
3. Engine running observe the DTC information with a scan tool. DTCs P2227, P2228, P2229, or P2230 should not set.
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.
Circuit/System Testing
1. Ignition OFF, disconnect the harness connector at the B17 BARO sensor.
2. Ignition OFF and all vehicle systems OFF. It may take up to 2 minutes for all vehicle systems to power down. Test for less than 5 ohm
between the low reference circuit terminal 2 and ground.
瀚慖f greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the K20
ECM.
3. Ignition ON, test for 4.8-5.2 V between the 5 V reference circuit terminal 1 and ground.
瀚慖f less than the specified range, test the 5 V reference circuit for a short to ground or an open/high resistance. If the circuit tests normal,
replace the K20 ECM.
瀚慖f greater than the specified range, test the 5 V reference circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM.
4. Verify the scan tool BARO Sensor parameter is less than 1 kPa (0.2 psi).
瀚慖f greater than the specified range, test the signal circuit terminal 3 for a short to voltage. If the circuit tests normal, replace the K20 ECM.
5. Install a 3 A fused jumper wire between the signal circuit terminal 3 and the 5 V reference circuit terminal 1. Verify the scan tool BARO
Sensor parameter is greater than 127 kPa (18.4 psi).
瀚慖f less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace
the K20 ECM.
6. If the circuits test normal, replace the B17 BARO sensor.
Repair Instructions
Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.
* Barometric Pressure Sensor Replacement (LF1) (See: Powertrain Management/Computers and Control Systems/Barometric Pressure
