Faulty ignition switch with worn internal contacts for the run/start circuit; Damaged or corroded wiring harness or connector at the ignition switch or BCM; Blown fuse or poor connection in the run/start circuit power supply; Failed body control module (BCM) or ignition switch module; Aftermarket alarm or remote start system improperly spliced into the ignition circuit; Loose or damaged ground connection for the ignition switch or BCM

DTC codes / B09xx · Airbags, seats, doors, lights and comfort systems / B0980

B0980Ignition Switch Run/Start Position Circuit

Q: What does code B0980 mean?

Ignition Switch Run/Start Position Circuit. B0980 indicates that the body control module (BCM) or ignition switch module has detected an unexpected voltage condition on the ignition switch run/start position circuit, meaning the signal does not match the expected state for the current ignition mode. The computer sets this code when the voltage on the run/start circuit is out of range, stuck, or inconsistent with other ignition inputs, which can affect power distribution to multiple systems.

B0980 indicates that the body control module (BCM) or ignition switch module has detected an unexpected voltage condition on the ignition switch run/start position circuit, meaning the signal does not match the expected state for the current ignition mode. The computer sets this code when the voltage on the run/start circuit is out of range, stuck, or inconsistent with other ignition inputs, which can affect power distribution to multiple systems.

SystemBody

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaAirbags, seats, doors, lights and comfort systems

Symptoms you may notice

The engine may not crank or start when the key is turned to the start position
The warning light for the ignition system or a general body fault may illuminate
Accessories may remain powered on after the key is turned off, or may not power on in the run position
Intermittent stalling or sudden loss of electrical power while driving
Often no symptoms besides the warning light, especially if the fault is intermittent

Common causes, most likely first

Faulty ignition switch with worn internal contacts for the run/start circuit
Damaged or corroded wiring harness or connector at the ignition switch or BCM
Blown fuse or poor connection in the run/start circuit power supply
Failed body control module (BCM) or ignition switch module
Aftermarket alarm or remote start system improperly spliced into the ignition circuit
Loose or damaged ground connection for the ignition switch or BCM

How to diagnose and fix it

Verify the battery voltage and condition, as low voltage can cause false ignition circuit codes
Inspect the ignition switch connector and wiring for corrosion, looseness, or damage
Check all fuses related to the ignition run/start circuit and replace any that are blown
Use a scan tool to monitor ignition switch position data and compare with actual key position
Perform a voltage drop test on the run/start circuit from the ignition switch to the BCM
If the switch is faulty, replace the ignition switch and clear the code
If wiring and switch are good, test the BCM and replace if internal failure is confirmed

Before you replace the ignition switch

A common misdiagnosis is replacing the ignition switch when the real problem is a corroded connector or chafed wire hidden under the dash.
Aftermarket accessories like remote starters or alarm systems often back-probe the ignition circuit and can introduce voltage irregularities that set B0980.
The code can be set by a weak battery or poor ground even if the ignition switch itself is perfectly functional.
On some vehicles, the run/start signal is transmitted over a data bus rather than a dedicated wire, so a communication fault can mimic an ignition switch failure.
Always check for technical service bulletins (TSBs) for the specific vehicle, as some models have known issues with the ignition switch or BCM software.

Can I keep driving with B0980?

If the engine starts and runs normally, you can drive to a repair shop, but avoid turning the engine off if restarting is uncertain. If the engine will not start or electrical power is intermittent, do not drive and have the vehicle towed to prevent safety risks.

Tools that help

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.