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 C0914 03: Device Voltage Reference Output 1 Circuit Voltage Below Threshold

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

B+

C0914

C0914

--

--

Ground

--

C0914

--

--

Circuit/System Description

The adaptive cruise module (ACM) monitors the system voltage to ensure that the voltage stays within the proper range. Damage to components, and incorrect data may occur when the voltage is out of range.

Conditions for Running the DTC

    • The vehicle speed is above 8 km/h (5 mph).
    • The system voltage is between 9.0-18 volts.

Conditions for Setting the DTC

The ACM detects a system voltage below 8.5 volts for 1 second.

Action Taken When the DTC Sets

    • The ACM will command the RADAR NOT READY warning message to be illuminated on the driver information center (DIC).
    • The Cruise Control will be disabled.

Conditions for Clearing the DTC

    • The history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
    • Using the scan tool Clear DTC Information function can clear the DTC.
    • The system voltage is greater than 9.0 volts.

Reference Information

Schematic Reference

Cruise 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 for scan tool information

Circuit/System Verification

  1. Engine running, measure and record the voltage at the battery terminals.
  2. Verify that the battery voltage is 12.6-15.5 volts.
  3. If the battery voltage is not within the specified range, refer to Charging System Test
  4. Engine running, observe the scan tool battery voltage signal parameter. The reading should be between 12.6 and 15.5 volts.

Circuit/System Testing

  1. Ignition OFF, disconnect the harness connector at the adaptive cruise module (ACM).
  2. Ignition OFF, test for less than 3 ohms between the ground circuit terminal 12 and ground.
  3. If greater than the specified value, test the ground circuit for an open/high resistance.
  4. Ignition ON, verify a test lamp illuminates between the B+ circuit terminal 15 and ground.
  5. If the test lamp did not illuminate , test the circuit for an open/high resistance.
  6. If all circuits test normal, test or replace the ACM.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for ACM replacement, setup, and programming