What it means
The supply voltage on injector group G is above the upper limit. Overvoltage on the group-G supply can mis-time or damage the injectors. Causes: charging-system overvoltage, a stuck supply relay or regulator, or a wiring fault shorting the group-G supply to a higher voltage.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
This code concerns the shared supply-voltage circuit for fuel injector group G. The control module monitors that feed for voltage above its expected range. P217C sets when the group-G supply is too high, which can disrupt injector operation and may damage electrical components.
Common causes
Most likely first.
- Charging system overvoltage
- Connector pins corroded - high contact resistance
- Supply wire pinched against B+ source
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 scan for charging-system and injector codes to determine whether the high reading appeared alongside a broader voltage problem.
- Inspect the group-G supply harness and connectors for a pinched wire or contact with a higher-voltage source.
- Measure system charging voltage under the manufacturer's specified conditions, since charging-system overvoltage can affect the injector supply.
- Using the wiring diagram, measure group-G feed voltage and inspect the relay or regulator for a stuck or incorrect output.
- If charging and external wiring are within specification, check module connectors and the circuit monitoring path for a fault.
Common fixes
- Repair a group-G wire shorted to a higher-voltage source.
- Repair a loose or damaged connector that is causing an abnormal circuit reading.
- Replace a faulty supply relay or regulator after confirming its output is stuck high.
- Repair the charging-system fault if system voltage exceeds the manufacturer's specification.
- Repair a confirmed module circuit fault after external causes are ruled out.
Can I keep driving?
Avoid unnecessary driving until the high supply voltage is diagnosed, especially if the engine misfires or other electrical warnings appear. Overvoltage can worsen injector or control-circuit damage; stop if the engine runs severely rough or smoke appears.
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.