What it means
The supply rail to injector group C 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-C 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 C shares a supply circuit that provides the power needed for its injectors to operate. This code sets when the engine control module detects an open or missing supply path to group C, so the injectors in that group may not fire.
Common causes
Most likely first.
- Open supply wire or blown fuse
- Pin pushed back out of connector body
- Cracked solder joint inside the module or sensor
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 C supply fault occurs and which cylinders are affected.
- Inspect the group C fuse, relay, connectors, and harness for a blown fuse, disconnected plug, pushed-back pin, or broken wire.
- Check for supply voltage at the group C connector with the circuit active and compare the result with the manufacturer's specification.
- Test continuity through the group C supply wiring and fuse path with power safely isolated, looking for an open circuit.
- If the wiring and relay path are intact, check the relevant module connector and output using the vehicle's service information.
Common fixes
- Reconnect a loose group C supply connector or reseat a pushed-back terminal.
- Repair a broken or open group C supply wire.
- Replace a blown fuse after locating and correcting the cause.
- Replace a failed injector supply relay.
Can I keep driving?
If the engine is running on fewer cylinders or misfiring, avoid driving because unburned fuel can overheat and damage the catalytic converter. Arrange repair before normal use, particularly if the engine runs very roughly.
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.