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 Descriptors

DTC B1325 03 : Device Power 1 Circuit Voltage Below Threshold
DTC B1325 07: Device Power 1 Circuit Voltage Above Threshold

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
IGN I | B1325 | B1325 | -- | --
Ground | -- | B1325 | -- | --

### Circuit/System Description

The sensing and diagnostic module (SDM) monitors the system voltage through the ignition voltage signal circuit. If the SDM senses that system voltage is outside of its normal range, DTC B1325 will set. Damage to components, and incorrect data may occur when the voltage is out of range.

### Conditions for Running the DTC

• | The voltage supplied to the SDM are in the range of 7-26 V.

• | The ignition is ON.

• | The engine is running.

### Conditions for Setting the DTC

#### B1325 03

The SDM detects a system voltage below 9 V for 5 seconds.

#### B1325 07

The SDM detects a system voltage above 18 V for 5 seconds.

### Action Taken When the DTC Sets

• | The SDM commands the AIR BAG indicator ON

• | The SIR system is disabled and no deployments are allowed.

### Conditions for Clearing the DTC

The DTC clears when the system voltage returns to a normal range.

### Diagnostic Aids

• | A high or low voltage DTC set in multiple control modules indicates a concern in the charging system.

• | A possible cause of this DTC could be overcharging with a battery charger or jump starting.

• | A high or low voltage value in multiple control modules indicates a concern in the charging system.

### Reference Information

#### Schematic Reference

SIR Schematics

#### Connector End View Reference

Component Connector End Views

#### Description and Operation

Charging System Description and Operation

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### Scan Tool Reference

Control Module References for scan tool information

### Circuit/System Verification

1. Engine running measure and record the voltage at the battery terminals.
2. . Verify that the battery voltage is 12.6-15.5 V.

⇒ | If the battery voltage is not within the specified range, refer to Charging System Test

3. Engine running, observe the scan tool SDM Battery Positive Voltage parameter.
4. Verify that the scan tool displays a value that is within 2 V of the battery terminal voltage.

### Circuit/System Testing

Caution: Refer to SIR Service Precautions in the Preface section.

1. Ignition OFF. Disconnect the harness connectors at the SDM.
2. Verify that there is less than 3.0 Ω between the ground circuit terminal 16 X2 and ground

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

3. Ignition ON, verify a test lamp illuminates between the ignition 1 voltage circuit terminal 29 X2 and ground

⇒ | If test lamp did not illuminate, test the ignition 1 voltage circuit for a short to ground or an open/high resistance.

4. If all the circuits test normal, replace the SDM.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

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