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 B1405 03: Device Voltage Reference Output 2 Circuit Low Voltage - Battery Current Sensor
DTC B1405 07: Device Voltage Reference Output 2 Circuit High Voltage - Battery Current Sensor

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
5 V Reference | B1405 03, B1516 08 | B1516 08 | B1405 07 | --
Signal | B1516 08 | B1516 08 | B1516 08 | B1516 08, B1516 66
Low Reference | -- | B1516 08 | -- | --

### Typical Scan Tool Data

#### Battery Current

Circuit | Short to Ground | Open | Short to Voltage
--- | --- | --- | ---
Operating Conditions: Ignition ON, engine OFF. Headlamps and all accessories OFF. Parameter Normal Range: -5 amps to -10 amps
5 V Reference | -59.9 amps | -59.9 amps | --
Signal | -59.9 amps | 59.9 amps | 59.9 amps
Low Reference | -- | 59.9 amps | --

### Circuit/System Description

The battery current sensor is a 3-wire hall effect current sensor. The battery current sensor monitors the current through the negative battery cable. The BCM supplies a 5 V reference to the battery current sensor. The BCM monitors the voltage on the 5 V reference circuit, to ensure that it is in the correct range.

### Conditions for Running the DTC

The BCM is awake.

### Conditions for Setting the DTC

The BCM detects that the 5 V reference circuit is shorted to ground or shorted to voltage.

### Action Taken When the DTC Sets

The regulated voltage control (RVC) is disabled.

### Conditions for Clearing the DTC

The DTC passes when the voltage on the 5 V reference circuit returns to the normal range for 5 seconds.

### Reference Information

#### Schematic Reference

Starting and Charging 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. Ignition ON, engine OFF, turn off the headlamps and all accessories. Do not connect a battery charger.
2. Observe the scan tool Battery Current parameter. The reading should be between -5 and -10 amps, and change with the amount of current draw from the battery.

### Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the battery current sensor.
2. Ignition OFF and scan tool disconnected, open and close the driver door, and wait 1 minute. Test for less than 5 Ω between the low reference circuit terminal B and ground.

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

3. Ignition ON, test for 4.8-5.2 V between the 5 V reference circuit terminal A and ground.

⇒ | If less than the specified range, test the 5 V reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, then replace the BCM.

⇒ | If greater than the specified range, test the 5 V reference circuit for a short to voltage. If the circuit tests normal, then replace the BCM.

4. Verify the scan tool Battery Current is greater than 50 amps.

⇒ | If less than the specified range, test the signal circuit terminal C for a short to ground. If the circuit tests normal, replace the BCM.

5. Install a 3 A fused jumper wire between the signal circuit terminal C and the low reference circuit terminal B. Verify the scan tool Battery Current is less than -50 amps.

⇒ | If greater than the specified range, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM.

6. If all circuits test normal, replace the battery current sensor.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Battery Negative Cable Replacement

• | Control Module References - for BCM replacement, setup, and programming.