B1405

DTC B1405

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.

DTC Descriptor
DTC B1405 00
- Device Voltage Reference Output 2 Circuit - Battery Current Sensor

Diagnostic Fault Information





Typical Scan Tool Data





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. It directly inputs to the body control module (BCM). It creates a 5-volt pulse width modulation (PWM) signal of 128 Hz, and varies the duty cycle. The BCM supplies a 5-volt reference to the battery current sensor. If the BCM detects that the 5-volt reference circuit is shorted, then DTC B1405 sets.

Conditions for Running the DTC

The BCM is awake.

Conditions for Setting the DTC

The BCM detects that the 5-volt 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-volt reference circuit returns to the normal range for 5 seconds.

Reference Information
Schematic Reference

Starting and Charging Schematics ([1][2]Electrical Diagrams)
Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

Charging System Description and Operation (Description and Operation)
Electrical Information Reference

* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)

Scan Tool Reference

Control Module References (Programming and Relearning) 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 BCM 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 ohms 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 volts between the 5-volt reference circuit terminal A and ground.

• If less than the specified range , test the 5-volt 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-volt reference circuit for a short to voltage. If the circuit tests normal, then replace the BCM.

4. Verify the scan tool BCM 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 3A fused jumper wire between the signal circuit terminal C and the low reference circuit terminal B. Verify the scan tool BCM 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 (Verification Tests) after completing the diagnostic procedure.

* Battery Current Sensor Replacement (Service and Repair)
* Control Module References (Programming and Relearning) for BCM replacement, setup, and programming.