B144A

DTC B144A

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 Descriptor

DTC B144A 02
- Run Power Relay Circuit Short to Ground

Diagnostic Fault Information






Circuit/System Description

The body control module (BCM) controls the ignition run relay through the control circuit by applying voltage to the ignition run relay coil control circuit. The ignition run relay is energized when the ignition switch is in ON or Start, or when a remote start is requested.

Conditions for Running the DTC

* The system voltage is between 9-16 V.

* The DTC can only run when the output is activated.

Conditions for Setting the DTC

The BCM detects a short to ground in the ignition run relay control circuit.

Action Taken When the DTC Sets

The module output driver will be shut down and not supply voltage to the ignition run relay control circuit.

Conditions for Clearing the DTC

* The current DTC will clear when the module request for the output is removed or the malfunction is no longer present.

* A history DTC clears when the module ignition cycle counter reaches the reset threshold of 50, without a repeat of the malfunction.

Diagnostic Aids

Short to voltage in the ignition run relay control circuit will cause the malfunction indicator lamp (MIL) to illuminate with the ignition key OFF.

Reference Information

Schematic Reference

Power Distribution Schematics Power Distribution Schematics

Connector End View Reference

Component Connector End Views Fuel Pump and Level Sensor Assembly

Description and Operation

Power Mode Description and Operation Power Mode

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 Control Module References for scan tool information

Circuit/System Verification

1. Ignition ON.

2. Verify the KR32E blower motor relay turns ON and OFF when commanding the run relay ON and OFF with a scan tool.

• If the KR32E blower motor relay does not turn ON and OFF
Refer to Circuit/System Testing

• If the KR32E blower motor relay turns ON and OFF

3. All OK.

Circuit/System Testing

1. Ignition OFF, disconnect the KR32E blower motor relay, ignition ON.

2. Connect a test lamp between the control circuit terminal 2 and ground.

3. Verify the test lamp turns ON and OFF when commanding the run relay ON and OFF with a scan tool.

• If the test lamp is always OFF

1. Ignition OFF, disconnect the harness connector at the K9 body control module.

2. Test for infinite resistance between the control circuit and ground.

• If less than infinite resistance, repair the short to ground on the circuit.

• If infinite resistance

3. Test for less than 2 ohms in the control circuit end to end.

• If 2 ohms or greater, repair the open/high resistance in the circuit.

• If less than 2 ohms, replace the K9 body control module.

• If the test lamp is always ON

1. Ignition OFF, disconnect the harness connector at the K9 body control module, ignition ON.

2. Test for less than 1 V between the control circuit and ground.

• If 1 V or greater, repair the short to voltage on the circuit.

• If less than 1 V, replace the K9 body control module.

• If the test lamp turns ON and OFF

4. Test or replace the KR32E blower motor relay.

Repair Instructions

Perform the Diagnostic Repair Verification Verification Tests after completing the repair.

* Relay Replacement (Within an Electrical Center) Relay Replacement (Within an Electrical Center)Relay Replacement (Attached to Wire Harness) Relay Replacement (Attached to Wire Harness)

* Control Module References Control Module References for the body control module replacement, programming and setup