B1428
DTC B1428
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 B1428 00
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Ignition Switched Power Relay 1 Circuit
Diagnostic Fault Information
Circuit/System Description
The body control module (BCM) controls the ignition relay through the run/crank ignition circuit by applying voltage to the circuit. The ignition relay is energized when the ignition switch is in the RUN or CRANK position, or when a remote start is requested.
Conditions for Running the DTC
* The system voltage is between 9-16 V.
* The ignition 1 relay control output is active.
Conditions for Setting the DTC
The BCM detects a short to ground on the ignition circuit.
Action Taken When the DTC Sets
The BCM disables the ignition output driver.
Conditions for Clearing the DTC
* The condition responsible for setting the DTC no longer exists.
* A history DTC will clear once 50 consecutive malfunction-free ignition cycles have occurred.
Reference Information
Schematic Reference
Power Moding Schematics Power Moding Schematics
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 Testing
1. Ignition OFF, disconnect the KR73 ignition main relay.
2. Test for less than 10 omhs between the ground circuit terminal 86 and ground.
• If greater than the specified range, test the ground circuit for an open/high resistance.
3. Connect a test lamp between the B+ circuit terminal 85 and the ground circuit terminal 86.
4. Cycle the ignition ON and OFF. The test lamp should turn ON and OFF when changing between ON and OFF.
• If the test lamp is always ON, test the B+ circuit for a short to voltage. If the circuit tests normal, replace the BCM.
• If the test lamp is always OFF, test the B+ circuit for a 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 KR73 ignition main relay.
Component Testing
1. Ignition OFF, disconnect the KR73 ignition main relay.
2. Test for 60 - 180 omhs between the B+ terminal 85 and the ground terminal 86 of the KR73 ignition main relay.
• If not within the specified range, replace the KR 73 ignition main relay.
3. Test for infinite resistance between the following terminals:
* 30 and 86
* 30 and 87
* 30 and 85
* 85 and 87
• If not the specified value, replace the KR73 ignition main relay.
4. Install a 3 A fused jumper wire between relay terminal 85 and 12 V. Install a jumper wire between relay terminal 86 and ground. Test for less than 2 omhs between terminals 30 and 87.
• If greater than specified range, replace the KR73 ignition main relay.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.
Control Module References Control Module References for BCM replacement, setup, and programming