• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
• | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
• | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
---|---|---|---|---|
Ignition Main Relay Control | B144B 02 | 1 | 2 | -- |
1. No Start. 2. Vehicle will start and continue to run after the ignition key is removed. |
The body control module (BCM) controls the ignition main relay through the control circuit by applying voltage to the circuit. The ignition main relay is energized when the ignition switch is in ON or START, or when a remote start is requested.
• | The system voltage is between 9-16 V. |
• | The DTC can only run when the output is activated. |
The BCM detects a short to ground in the ignition main relay control circuit.
The module output driver will be shut down and not supply voltage to the ignition main relay control circuit.
• | 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. |
Short to voltage in the ignition main relay control circuit will cause the malfunction indicator lamp (MIL) to illuminate with the ignition key OFF, and the engine will remain running if started and the ignition key is removed.
Power Mode Description and Operation
Control Module References for scan tool information
⇒ | If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the K9 BCM. |
⇒ | If the test lamp is always OFF, test the control circuit for a short to ground or open/high resistance. If the circuit tests normal, replace the K9 BCM. |
⇒ | If the resistance is not within the specified range, replace the KR73 ignition main relay. |
• | 30 and 86 |
• | 30 and 87 |
• | 30 and 85 |
• | 85 and 87 |
⇒ | If less than specified, replace the KR73 ignition main relay. |
⇒ | If greater than specified, replace the KR73 ignition main relay. |
Perform the Diagnostic Repair Verification after completing the repair.
Refer to Control Module References for BCM replacement, setup, and programming