What it means
Ignition D control signal stuck low — short to ground. Wiring faults of this kind typically come from chafing, water ingress at connector seals, or pin push-back — a wiggle test on the harness while the code is active often confirms the location.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
The PCM sends Ignition D control signals to the ignition hardware and monitors the circuit's electrical state. This code sets when the Ignition D line is held near ground rather than switching as expected, potentially disabling the associated ignition channel.
Common causes
Most likely first.
- Short to ground
- Connector pins corroded - high contact resistance
- Harness chafing through insulation
Symptoms
- Rough running or misfire
- Hard starting or no start
- Reduced engine power
How to diagnose it
- Record freeze-frame data and review live misfire or ignition data to see whether the fault is active and linked to rough running.
- Inspect the Ignition D wire and connector for chafing through insulation, moisture, corrosion, pushed-back pins, or contact with ground.
- Using the vehicle wiring information, test whether the Ignition D signal is being pulled to ground and trace any short in the harness.
- Wiggle the Ignition D harness and connector while monitoring the signal to check for a movement-related change.
- If wiring and terminals are sound, test the Ignition D ignition component and PCM driver following the manufacturer's procedure.
Common fixes
- Repair the Ignition D wire where it is shorted to ground.
- Clean or replace corroded terminals and restore connector pin fit.
- Repair a damaged seal and secure the harness away from rubbing or grounding points.
- Replace a confirmed faulty ignition component or PCM driver.
Can I keep driving?
If the engine runs roughly or misfires, avoid hard acceleration and long trips because the affected ignition channel may worsen misfiring and emissions. If the engine stalls or is hard to start, avoid driving until diagnosed.
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.