For 1990-2009 cars

### Diagnostic Instructions

• | 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.

### DTC Descriptor

DTC B1428: Ignition Switched Power Relay 1 Circuit

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
Relay Control | B1428 | 1 | 2 | --
Ground | -- | 1 | -- | --
1. Ignition 1 Relay will not Energize 2. Ignition 1 Relay is Always Energized

### Circuit/System Description

The instrument panel cluster (IPC) controls the ignition 1 relay through the relay coil control circuit by applying voltage to the circuit. The ignition 1 relay is energized when the ignition switch is in ON or START, or when a remote start is requested.

### Conditions for Running the DTC

Battery voltage must be between 9-16 volts.

### Conditions for Setting the DTC

The ignition 1 relay control circuit is shorted to ground.

### Action Taken When the DTC Sets

The ignition 1 relay control will be disabled.

### Conditions for Clearing the DTC

The current DTC clears when the fault is no longer present.

### Reference Information

#### Schematic Reference

Power Distribution Schematics

#### Connector End View Reference

Component Connector End Views

#### Description and Operation

Power Mode Description and Operation

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

### Circuit/System Testing

1. Ignition OFF, disconnect the ignition 1 relay.
2. Test for less than 1 ohm between the ground circuit terminal 85 and ground.

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

3. Connect a test lamp between the control circuit terminal 86 and ground.
4. Turn the ignition switch 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 a short to voltage. If the circuit tests normal, replace the IPC.

⇒ | If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the IPC.

5. If all circuits test normal, test or replace the ignition 1 relay.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for IPC replacement, programming, and setup.