What it means
Disable line A voltage below expected range. A communication loss with this module breaks any function relying on its data — diagnostic tools may show 'no response' and dependent modules can fall into limp mode.
At a glance
- Usually lights the warning light of the system that lost communication
How it works
The disable line carries a request from the gateway or master module to put Control Module A into a safe state. This code means the line voltage is lower than expected, commonly because it is shorted to ground; the module may fail to receive the request or lose communication.
Common causes
Most likely first.
- Wiring shorted to ground
- Gateway module routing CAN messages incorrectly
- CAN terminating resistor (120 Ω) drifted out of spec
Symptoms
- Multiple warning lights may illuminate
- Affected modules may go into limp mode or shut down
- Specific functions inoperative depending on module
- Diagnostic tools may show communication faults
How to diagnose it
- Record all module codes and freeze-frame details, looking for other low-voltage or communication faults that appeared at the same time.
- Use a scan tool to check whether Control Module A responds and whether the gateway's disable command and module status agree.
- Inspect the disable-line harness and connectors for chafing, crushed insulation, moisture, or contact with ground.
- Follow the manufacturer's isolation procedure, then test the disable line for a short to ground and check its voltage against specification.
- If the line tests correctly, assess gateway routing and CAN termination using the manufacturer's network test procedure.
Common fixes
- Repair chafed wiring or a connector causing the disable line to short to ground.
- Secure the harness away from grounded edges and moving parts.
- Correct a confirmed gateway routing or configuration fault.
- Repair a CAN termination fault if measured outside the manufacturer's specification.
Can I keep driving?
If the vehicle is in limp mode, a module has shut down, or an essential function is unreliable, do not continue driving. Otherwise, limit driving to a necessary short trip because the fault can interrupt functions that depend on Control Module A.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.