The BCM does not detect the accessory signal for more than 10 seconds in the current ignition cycle.
Action Taken When the DTC Sets
- The BCM stores DTC to memory.
- The BCM operates in a fail-safe power mode dependent on the last valid power mode detected and the state of the engine run flag data on the class 2 serial data communications circuits.
- The other modules on the vehicle operate in a fail-safe power mode dependent on the last valid power mode transmitted by the BCM and the state of the engine run flag on the class 2 serial data communications circuits.
Conditions for Clearing the DTC
- A current DTC clears on the next malfunction free cycle.
- A history DTC clears when the module ignition cycle counter reaches the reset threshold, without a repeat of the malfunction.
Diagnostic Aids
A history DTC may be caused by an intermittent short or open in the accessory circuit. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
- 3: This tests the ignition switch for a short circuit between the B+ supply circuit and the accessory circuit in the Off position.
- 4: This tests the wiring of the accessory circuit for a short to ground or voltage. This test may be expedited using the DTC to direct the testing. DTC B1382 short to ground or DTC B1383 short to voltage.
- 5: This tests the ignition switch for a closed circuit between the B+ supply circuit and the accessory circuit.
| Step | Action | Yes | No |
|---|---|---|---|
| Schematic Reference: Body Control System Schematics Connector End View Reference: Computer/Integrating Systems Connector End Views and Master Electrical Component List in Wiring Systems | |||
| 1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information |
| 2 | Install a scan tool. Turn the ignition ON, with the engine OFF. Check for DTCs in the range of B1382 to B1384 in the Body Control menu. Does the scan tool display DTC B1382 to DTC B1384 as current? | Go to Step 3 | Go to Diagnostic Aids |
| 3 | Disconnect the body control module (BCM) harness connectors C2 and C4. Place the ignition switch in the OFF position, leaving the key in the ignition. Test for a short to ground and a short to B+ between the accessory circuit and the ignition switch B+ supply circuit at the BCM harness connector. Refer to Body Control System Schematics and Circuit Testing in Wiring Systems. Did you find a short between the two circuits? | Go to Step 4 | Go to Step 5 |
| 4 | Disconnect the ignition switch harness connector. Test the accessory ignition switch circuit and the ignition switch B+ supply circuit for a short to ground or voltage at the BCM harness connector. Refer to the following: Body Control System Schematics Circuit Testing in Wiring Systems Wiring Repairs in Wiring Systems Did you find and correct the condition? | Go to Step 9 | Go to Step 7 |
| 5 | Turn the ignition switch to the RUN position. Test for continuity between the accessory terminal and the ignition switch B+ supply terminal on the BCM harness connector. Can you measure continuity? | Go to Step 8 | Go to Step 6 |
| 6 | Test the accessory and the ignition switch B+ supply terminals of the ignition switch harness connector, for intermittent or poor connections, and an open condition. Did you find and correct the condition? | Go to Step 9 | Go to Step 7 |
| 7 | Replace the ignition switch. Refer to Ignition Lock Cylinder Case Replacement in Steering Wheel and Column. Did you complete the replacement? | Go to Step 9 | |
| 8 | Replace the BCM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | Go to Step 9 | |
| 9 | Connect all disconnected connectors. Install the scan tool. Turn the ignition ON, with the engine OFF. Use the scan tool in order to clear the DTCs. Operate the vehicle within the conditions for running the DTCs as specified in the supporting text. Does the DTC reset? | Go to Step 1 | System OK |
DTC B1382, B1383, or B1384
Scheme 13
Circuit Description
The body control module (BCM) monitors the inputs Off/Run/Crank, Run/Crank and the Accessory signals supplied from the ignition switch. The BCM uses the sequence that the signals appear and their voltage levels to determine the power mode called for by the vehicle operator and the ignition switch. A +5 volt regulated voltage source is supplied by the BCM to the ignition switch over a discrete circuit. The ignition switch uses this voltage for Off/Run/Crank signal discrimination and the anti theft reference voltage generation. A constant battery positive voltage is also supplied to the ignition switch to generate the Run/Crank, Accessory and Key In signals. These signals are transmitted to the BCM over discrete circuits. The Accessory signal is also routed to the vehicles electronic control unit (ECU) and is used as a digital signal reference. The Run/Crank signal in conjunction with being supplied to the BCM is sent directly to the Run/Crank relay control coil.
DTC Descriptors
This diagnostic procedure supports the following DTCs
- DTC B1441 Device Ignition OFF, RUN, and CRANK Circuit
- DTC B1442 Device Ignition OFF, RUN, and CRANK Circuit Low
- DTC B1443 Device Ignition OFF, RUN, and CRANK Circuit High
Conditions for Running the DTC
- The BCM must be powered and must detect a change in the ignition switch circuit states.
- The vehicle battery must be fully charged.