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• | 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 | B144B 02* | B144B 04* | B144B 01* | - |
Control | B144B 02** | 1 | 2 | -- |
1. No Start 2. Engine will continue to run after the ignition is turned OFF * DTC set in keyless entry control module ** DTC Set in BCM |
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 energised when the vehicle is in Service Mode, the vehicle is ON or when a remote start is requested. This is part of the BCM's primary function in controlling the vehicle power mode.
The keyless entry control module controls the back-up power for the ignition run relay through the control circuit by applying voltage to the ignition circuit. This circuit is a pass-thru in the BCM and will energise the ignition circuit when the vehicle is in Service Mode, the vehicle is ON or when a remote start is requested.
System voltage is greater than 9 V
The ignition output is not active and a short-circuit to battery is detected 3 consecutive times on the ignition voltage circuit
A short-circuit to earth is detected on the ignition run relay coil control circuit
The ignition output is active and a short-circuit to earth is detected 3 consecutive times on the ignition voltage circuit
The ignition output is not active and an open-circuit is detected 20 consecutive times on the ignition voltage circuit
No action is taken
The ignition relay is deactivated when the fault is set. After 100 ms, the ignition run relay will be activated. If the fault is still set, the relay will be deactivated. The ignition run relay will again be activated after 100 ms. If this also results in a fault, the ignition run relay will be deactivated until a new ignition request is received.
• | The current DTC will clear when the malfunction is no longer present and an ignition request is received. |
• | A history DTC will clear after 40 malfunction-free ignition cycles. |
A short-circuit to voltage on the ignition run relay coil control will cause the engine to remain running after the vehicle mode is changed to OFF.
Power Mode Description and Operation
Control Module References for scan tool information
Vehicle in Service Mode, verify DTC B1330 is not set.
⇒ | If the DTC is set, refer to DTC B1325, B1330, B1517, C0800, C0899, C0900, C12E1, C12E2, P0562, P0563, P1A0C, P1A0D, or P1EFC . |
⇒ | If the test lamp does not illuminate, test the B+ circuit for an open-circuit/high resistance. If the B+ circuit fuse is open, test the B+ circuit for a short-circuit to earth. |
⇒ | If greater than the specified range, test the ignition circuit for a short-circuit to voltage. If the circuit tests normal, replace the K84 keyless entry control module. |
⇒ | If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K84 keyless entry control module. |
⇒ | If greater than the specified range, test the ground circuit for an open/high resistance. |
⇒ | If the test lamp is always ON, test the control circuit for a 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 a short to ground or open/high resistance. If the circuit tests normal, replace the K9 body control module. |
⇒ | If the resistance is not within the specified range, replace the KR74 ignition run relay. |
• | 30 and 86 |
• | 30 and 87 |
• | 30 and 85 |
• | 85 and 87 |
⇒ | If less than specified, replace the KR74 ignition run relay. |
⇒ | If greater than specified, replace the KR74 ignition run relay. |
Perform the Diagnostic Repair Verification after completing the repair.
• | Relay Replacement : Within an Electrical Center → Attached to Wire Harness |
• | Control Module References for BCM or keyless entry control module replacement, programming and set-up |
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