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 Descriptors

DTC B1E3A 03: Sensor Power Circuit Voltage Below Threshold

DTC B1E3A 07: Sensor Power Circuit Voltage Above Threshold

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

8-Volt Reference

B0958 06, B0959 06, B0960 06, B0961 06, B1E3A 07

B0958 06, B0959 06, B0960 06, B0961 06

B1E3A 07

--

Left Rear Object Sensor Signal

B0958 06

B0958 06

B0958 01

B0958 08, B0958 21

Left Middle Rear Object Sensor Signal

B0959 06

B0959 06

B0959 01

B0959 08, B0959 21

Right Middle Rear Object Sensor Signal

B0960 06

B0960 06

B0960 01

B0960 08, B0960 21

Right Rear Object Sensor Signal

B0961 06

B0961 06

B0961 01

B0960 08, B0960 21

Low Reference

--

B0958 06, B0959 06, B0960 06, B0961 06

--

--

Circuit/System Description

The object sensors are 3-wire sensors that are used to determine the distance between the vehicle and an object of interest. The object alarm module supplies 8 volts to the object sensors via the 8 volt reference circuit and provides ground via the low reference circuit. The object alarm module triggers the sensors in a sequential loop. After each sensor transmits, the object alarm module uses the sensor ring received though the signal circuit to calculate the distance and position of an object.

Conditions for Running the DTC

    • DTC B1325 is not set
    • Ignition voltage is between 9-16 volts
    • The vehicle is in REVERSE

Conditions for Setting the DTC

B1E3A 03

The object alarm module has detected the 8-volt reference circuit is less than 7.2 volts.

B1E3A 07

The object alarm module has detected the 8-volt reference circuit is greater than 9.2 volts.

Action Taken When the DTC Sets

    • Parking assist is disabled.
    • The object alarm module commands the red indicator ON.
    • The object alarm module sends a serial data message to the instrument panel cluster (IPC) to display SERVICE PARK ASSIST message in the driver information center (DIC) and a chime will sound.

Conditions for Clearing

    • The DTC will transition to history when the fault is no longer present.
    • A history DTC will clear after 100 malfunction-free ignition cycles.

Reference Information

Schematic Reference

Object Detection Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Object Detection 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

Ignition ON, transmission in REVERSE, verify that the scan tool Sensor Voltage Feed Output parameter is 7.2-9.2 volts.

Circuit/System Testing

  1. Ignition OFF, disconnect the harness connector at each of the object sensors.
  2. Ignition ON, verify DTC B1E3A is not set as current.
  3. If the DTC is set, test the 8-volt reference circuit terminal 1 for a short to voltage, short to ground, or an open/high resistance. If circuit tests normal, replace the object alarm module.
  4. Install each sensor harness connector one at a time, checking DTCs after each sensor is connected. Verify DTC B1E3A is not set as current.
  5. If the DTC is set, replace the object sensor that was connected immediately before the DTC set.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Rear Object Sensor Replacement
    •  Control Module References for object alarm module replacement, setup, and programming.