P2157
Fuel Injector Group D Supply Voltage Circuit High
The supply voltage on injector group D is above the upper limit. Overvoltage on the group-D 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-D supply to a higher voltage.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: medium
Symptoms
- Check engine light on
- Misfire or rough idle on the affected cylinder
- Increased fuel consumption
- Possible fuel smell or smoke from exhaust
Common causes
Ordered by how often each turns out to be the cause.
- Charging system overvoltageCommon
- Connector pins corroded - high contact resistanceLess likely
- Supply wire pinched against B+ sourceLess likely
Parts involved
- Fuel Injector Group D
P2157 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.