2010 Cadillac Truck Escalade RWD V8-6.0L Hybrid Page 2877

2010 Cadillac Truck Escalade RWD V8-6.0L Hybrid Page 2877

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

Special Tools

* J-23738-A Mityvac

* J-35555 Metal Mityvac

Circuit/System Verification

1. Ignition OFF, open the hood to disable the Auto-Stop function. Refer to Hybrid Modes of Operation Description ( See: Hybrid Drive

Systems/Description and Operation/Hybrid Modes of Operation).

2. Ignition ON, verify the scan tool hood position parameter displays Open.

瀚慖f the hood position does not display Open, refer to Diagnostic Trouble Code (DTC) List - Vehicle (See: Diagnostic Trouble Code

Descriptions/Diagnostic Trouble Code (DTC) List - Vehicle) for DTC P254F.

3. Ignition ON, observe the scan tool DTC information. Verify that DTCs P0641 or P0651 are not set.

瀚慖f a DTC is set, refer to DTC P0641 or P0651 (See: P Code Charts/P0641).

4. Ignition ON, observe the scan tool BARO parameter and compare the value to the Altitude Versus Barometric Pressure (See: Powertrain

Management/Computers and Control Systems/Specifications/Altitude Versus Barometric Pressure) table. The parameter should be within the

range specified in the table for the current altitude.

5. 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 BARO sensor.

2. Ignition OFF for 2 minutes and scan tool powered OFF, 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 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 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 ECM.

4. Verify the scan tool BARO sensor parameter is less than 2 kPa.

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 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 126 kPa.

瀚慖f less than the specified range, test the signal circuit for an open/high resistance or a short to ground. If the circuit tests normal, replace

the ECM.

6. If all circuits test normal, test or replace the BARO sensor.

Component Testing

Note: You must perform the Circuit/System Testing before proceeding with the Component Testing.

1. Ignition OFF, remove the BARO sensor.

2. Install a 3 A fused jumper wire between the 5 V reference circuit terminal 1 and the corresponding terminal of the BARO sensor.

3. Install a jumper wire between the low reference circuit terminal 2 of the BARO sensor and ground.

4. Install a jumper wire at terminal B of the BARO sensor.

5. Connect a DMM between the jumper wire from terminal 3 of the BARO sensor and ground.

6. Ignition ON, with the J-23738-A or J-35555, slowly apply vacuum to the sensor while observing the voltage on the DMM. The voltage

should vary between 0-5.2 V without any spikes or dropouts.

瀚慖f the voltage reading is erratic, replace the BARO sensor.