What does it mean?
P1215 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: Cylinder 3 Fuel Injection Circuit Short to B+ .
Symptoms
- Check engine lamp on with a misfire counted on cylinder 3
- Very rough idle and vibration through the body
- Overfuelling on that cylinder: black smoke, fuel odour, sooty or wet plug
- Loss of power and hesitation, sometimes a rich running condition on the whole bank
- Difficult starting after the engine has stood for a while
Likely causes
- Chafed injector wire touching a live terminal, a fuse box feed or an unprotected stud
- Corrosion or damp inside the injector connector shorting supply to control
- Injector with an internal short between coil and supply terminal
- Heat damage where the loom passes close to the exhaust manifold, melting the insulation
- Poorly insulated repair joint or a taped splice that has opened up
- Injector driver in the module destroyed by the fault
How to fix it
- Check whether the fault is on one cylinder or several, which separates an injector problem from a harness problem
- With the injector unplugged and the ignition on, measure the control wire; battery voltage confirms a short to battery
- Inspect the loom near the exhaust and any bracket for melted, hardened or rubbed insulation
- Open the connector and look for corrosion, coolant residue and pushed-back terminals
- Ohm the injector and compare it with the others, including a check from winding to supply pin
- Repair or reroute the damaged section of harness and retest the circuit
- Assess the module output stage last, after the wiring is proven clean