Diagnostic Instructions

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

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.