2010 Cadillac CTS Sedan AWD V6-3.6L Page 188

2010 Cadillac CTS Sedan AWD V6-3.6L Page 188

2. Observe the scan tool LGM Secondary Obstacle Detection parameter while pressing and releasing the B71R liftgate object sensor - right. The

reading should change from 3V-3.5V to 2.25-2.75V as the sensor is pressed and released.

瀚慖f the value does not change, test or replace the B71R liftgate object sensor - right.

3. Observe the scan tool LGM Secondary Obstacle Detection parameter while pressing and releasing the B71L liftgate object sensor - left. The

reading should change from 3V-3.5V to 2.25-2.75V as the sensor is pressed and released.

瀚慖f the value does not change, test or replace the B71L liftgate object sensor - left.

4. 4. If the B71 liftgate object sensors function normally and the liftgate will not power close or if the DTC is history, replace both B71 liftgate

object sensors.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the B71L liftgate object sensor - left.

2. Test for less than 30 ohm between the low reference circuit terminal A and ground.

瀚慖f greater than the specified range, test the low reference circuit for a short to voltage or an open/high resistance. If the circuit tests

normal, replace the K39 liftgate module.

3. Disconnect the harness connector at the B71R liftgate object sensor - right.

4. Ignition ON, test for 4.75-5.25 V between the signal circuit terminal B and ground.

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 K39 liftgate module.

瀚慖f greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the K39 liftgate module.

5. Test for less than 10 ohm between the signal circuit terminal A at the B71R liftgate object sensor - right and the signal circuit terminal B at

the B71L liftgate object sensor - left.

瀚慖f greater than the specified range, test the signal circuit for an open/high resistance.

6. Test for 8K-12K ohm between the signal terminal B and the low reference terminal A at the B71R liftgate object sensor - right.

瀚慖f not within the specified range, replace the B71R liftgate object sensor - right.

7. Test for 8K-12K ohm between the signal terminal B and the low reference terminal A at the B71L liftgate object sensor - left.

瀚慖f not within the specified range, replace the B71L liftgate object sensor - left.

8. If all circuits test normal, replace the K39 liftgate module.

Repair Instructions

Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the repair.

* Liftgate Side Upper Sensor Replacement (See: Body and Frame/Doors, Hood and Trunk/Trunk / Liftgate/Trunk / Liftgate Position

Sensor/Service and Repair)

* Control Module References (See: Testing and Inspection/Programming and Relearning) for liftgate module replacement, setup and

programming

B0158

DTC B0158 or B0163

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 B0158 03

- Outside Air Temperature Sensor Voltage Below Threshold