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 B3006 5A: Hood Ajar Circuit Plausibility Failure

Circuit/System Description

The body control module (BCM) monitors the voltage input of the hood open switch signal circuit and the hood open closed switch signal circuit. With the hood open, the hood ajar portion of the switch is closed, grounding the Hood Ajar Switch Signal circuit from the BCM, and the hood closed portion of the switch is open. With the hood closed, the hood closed portion of the switch is closed, grounding the Hood Closed Switch Signal circuit from the BCM, and the hood ajar portion of the switch is open. During proper operation, the 2 separate voltage signals at the BCM should never be at the same voltage with the hood opened or closed.

Conditions for Running the DTC

This DTC shall run when the Run/Crank Relay is enabled.

Conditions for Setting the DTC

If both the hood open switch signal circuit and the hood closed switch signal circuit are simultaneously in an active or inactive state.

Action Taken When the DTC Sets

    • Remote start functions will be disabled.
    • The hood ajar switch inputs will be ignored by content theft deterrent (CTD).

Conditions for Clearing the DTC

The DTC will clear when conditions for setting the DTC are no longer present.

Reference Information

Schematic Reference

Remote Function Schematics

Connector End View Reference

Remote Function Connector End Views

Description and Operation

Keyless Entry System Description and Operation

Electrical Information Reference

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

Scan Tool Reference

    •  Scan Tool Data List
    •  Scan Tool Data Definitions

Circuit/System Verification

Ignition ON, observe the scan tool Hood Open Switch and Hood Closed Switch parameters. With the hood open, the Hood Open Switch parameter should read Active and the Hood Closed Switch parameter should read Inactive. With the hood closed, the Hood Open Switch parameter should read Inactive and the Hood Closed Switch parameter should read Active.

Circuit/System Testing

  1. Ignition OFF, disconnect the harness connector at the hood ajar switch.
  2. Ignition OFF, test for less than 1.0 ohm of resistance between the ground circuit terminal C and ground.
  3. If greater than the specified value, test the ground circuit for an open/high resistance.
  4. Ignition ON, verify the scan tool BCM Hood Closed Switch and Hood Open Switch parameters are Inactive.
  5. If not the specified value, test the applicable signal circuit for a short to ground. If the circuit tests normal, replace the BCM.
  6. Install a 3A fused jumper wire between the signal circuit terminal A and ground. Verify the scan tool Hood Open Switch parameter is Active.
  7. If not the specified value, test the signal circuit for a short to voltage or and open/high resistance. If the circuit tests normal, replace the BCM.
  8. Install a 3A fused jumper wire between the signal circuit terminal B and ground. Verify the scan tool Hood Closed Switch parameter is Active.
  9. If not the specified value, test the signal circuit for a short to voltage or and open/high resistance. If the circuit tests normal, replace the BCM.
  10. If all circuits test normal, test or replace the hood ajar switch.

Component Testing

Hood Ajar Switch

  1. Ignition OFF, disconnect the harness connector at the hood ajar switch.
  2. With the switch in the hood closed position, test for infinite resistance between the ground terminal C and the signal terminal A.
  3. If not the specified value, replace the hood ajar switch.
  4. Test for less than 2.0 ohms of resistance between the ground terminal C and the signal terminal B.
  5. If greater than the specified range, replace the hood ajar switch.
  6. With the switch in the hood open position, test for infinite resistance between the ground terminal C and the signal terminal B.
  7. If not the specified value, replace the hood ajar switch.
  8. Test for less than 2.0 ohms of resistance between the ground terminal C and the signal terminal A.
  9. If greater than the specified range, replace the hood ajar switch.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Hood Primary and Secondary Latch Replacement
    •  Control Module References for BCM replacement, programming and setup