B270A

DTC B270A

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Diagnostic Procedure Instructions) provides an overview of each diagnostic category.

DTC Descriptors
DTC B270A 01
- Park Lock Solenoid Control Circuit Short to Voltage

DTC B270A 02
- Park Lock Solenoid Control Circuit Short to Ground

DTC B270A 04
- Park Lock Solenoid Control Circuit Open

Diagnostic Fault Information





Circuit/System Description

The body control module controls the automatic transmission park lock control solenoid by providing a battery positive voltage to the solenoid. The body control module controls the voltage supply circuit to the automatic transmission park lock control solenoid. The BCM monitors the voltage and current flow of the control circuit.

Conditions for Running the DTC

* The ignition switch is in the ON position.
* The brake pedal is pressed.
* The transmission is in the PARK position.
* The DTC runs continuously once the above conditions are met.

Conditions for Setting the DTC

B270A 01

The body control module detects a short to voltage in the automatic transmission park lock control solenoid control circuit for 1 second.

B270A 02

The body control module detects a short to ground in the automatic transmission park lock control solenoid control circuit for 1 second.

B270A 04

The body control module detects an open in the automatic transmission park lock control solenoid control circuit for 1 second.

Action Taken When the DTC Sets

The body control module will not attempt to enable the voltage supply circuit of the automatic transmission park lock control solenoid until the next key cycle.

Conditions for Clearing the DTC

* A current DTC B270A will clear when the malfunction is no longer present and the ignition switch is cycled.
* A history DTC will clear after 100 ignition cycles with no current DTC active during the 100 ignition cycles.

Reference Information
Schematic Reference

Shift Lock Control Schematics (Electrical Diagrams)
Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

Automatic Transmission Shift Lock Control Description and Operation (Description and Operation)
Electrical Information Reference

* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)

Scan Tool Reference

Control Module References (Programming and Relearning) for scan tool information

Circuit/System Verification

1. Ignition ON, observe the scan tool Brake Pedal Switch parameter while pressing and releasing the brake pedal. The parameter should change from ON to OFF when the brake pedal is depressed.

• If the parameter does not change, refer to Stop Lamps Malfunction (Stop Lamps Malfunction).

2. While pressing the brake pedal, the vehicle operator should be able to move the shifter lever out of the park position.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the M7 transmission shift lock control solenoid actuator.
2. Ignition OFF, test for less than 1.0 Ohms between the ground circuit terminal 1 and ground.

• If greater than the specified range, test the ground circuit for an open/high resistance.

3. Install a test lamp between the ground circuit terminal 1 and the control circuit terminal 3.
4. Ignition ON, command the scan tool Shift Lock Solenoid Actuator ON and OFF. The test lamp should turn ON and OFF when changing between the commanded states.

• If the test lamp is always ON, test the control circuit for short to voltage. If the circuit tests normal, replace the K9 body control module.
• If the test lamp is always OFF, test the control circuit for short to ground or an open/high resistance. If the circuit tests normal, replace the K9 body control module.

5. If all circuits test normal, test or replace the M7 transmission shift lock control solenoid actuator.

Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

* Transmission Control Replacement (Transmission Control Replacement)
* Control Module References (Programming and Relearning) for BCM replacement, setup, and programming