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 B1529 00: Device Voltage Reference Output 5 Below/Above Threshold

Circuit/System Description

The body control module (BCM) provides a 5-volt reference voltage to the cruise control switch and the touch up touch down (TUTD) selector for the transmission.

Conditions for Running the DTC

    • The ignition is ON.
    • The cruise switch is ON.

Conditions for Setting the DTC

    • The BCM detects an invalid voltage signal on the cruise control/TUTD switch signal circuit.
    • The above condition is present for 0.5 second.

Action Taken When the DTC Sets

The BCM stores the DTC information into memory when the diagnostic runs and fails.

Conditions for Clearing the DTC

    • The condition for setting the DTC is no longer present.
    • A history DTC clears after 40 fault-free ignition cycles.
    • The DTC can be cleared using a scan tool.

Reference Information

Schematic Reference

    •  Cruise Control Schematics
    •  Body Control System Schematics
    •  Steering Wheel Secondary/Configurable Control Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

Scan Tool Reference

Control Module References

Circuit/System Testing

  1. Verify that no other DTCs are not set.
  2. If any other DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle
  3. Ignition OFF, disconnect the harness connector at the TUTD selector.
  4. Ignition ON, Connect a DMM between the reference circuit terminal of the TUTD harness connector and a known ground.
  5. If the DMM does not read 5 volts test the reference circuit for a open/high resistance or short to ground.
    If all circuits test normal replace the BCM.

Repair Instructions

Perform the Diagnostic Repair Verification .

Control Module References