GM Service Manual Online
For 1990-2009 cars only

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 00: Device Voltage Reference Output 2 Circuit - Battery Current Sensor

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

5-Volt Reference

B1405 00, B1516 08

B1516 08

B1405 00

--

Signal

B1516 08

B1516 08

B1516 08

B1516 08, B1516 66

Low Reference

--

B1516 08

--

--

Typical Scan Tool Data

Battery Current - BCM

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-Volt 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. 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

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 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.
  3. If greater than the specified range, test the low reference circuit for an open/high resistance.
  4. Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal A and ground.
  5. 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.
  6. Verify the scan tool BCM Battery Current is greater than 50 amps.
  7. 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.
  8. 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.
  9. 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.
  10. If all circuits test normal, replace the battery current sensor.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Battery Current Sensor Replacement
    •  Control Module References for BCM replacement, setup, and programming.