What it means
The supply rail to injector group D is open, so none of the injectors in this group can fire. The affected cylinders produce no power and the engine runs rough or on reduced cylinders. Causes: a broken supply wire, an open relay or fuse, or a disconnected group-D supply connector.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
Injector group D shares a power supply that provides the energy needed for its injectors to operate. This code sets when the engine control module detects an open supply path to group D, so those injectors may receive no usable power and their cylinders may misfire.
Common causes
Most likely first.
- Open supply wire or blown fuse
- Loose or disconnected connector
- Failed injector power supply relay
Symptoms
- Check engine light on
- Misfire or rough idle on the affected cylinder
- Increased fuel consumption
- Possible fuel smell or smoke from exhaust
How to diagnose it
- Record freeze-frame data and check live misfire counts to identify when the group D supply fault occurs and which cylinders are affected.
- Inspect the group D fuse, relay, connectors, and harness for a blown fuse, disconnected plug, loose terminal, or broken wire.
- Check for supply voltage at the group D connector with the circuit active and compare it with the manufacturer's specification.
- Test continuity through the group D supply wire and fuse path with power safely isolated to locate an open.
- If the supply wiring is intact, test the relay and check the relevant module connector and output using the vehicle's service information.
Common fixes
- Reconnect a loose or disconnected group D supply connector.
- Repair an open or broken group D supply wire.
- Replace a blown fuse after identifying and correcting its cause.
- Replace a failed injector power supply relay.
Can I keep driving?
If the engine is misfiring badly or running on fewer cylinders, avoid driving because unburned fuel can damage the catalytic converter. Have the group D open circuit repaired before returning to normal use.
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.