What does it mean?
P1268 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: Cylinder 8 High To Low Side Short .
Symptoms
- The MIL is on, flashing if the misfire is heavy enough to threaten the catalyst
- Misfire on cylinder 8 with vibration at idle and under light load
- Power loss and hesitation when accelerating
- Raw fuel smell from the exhaust and higher consumption
- Uneven idle that may improve at higher engine speeds
- Possible extra exhaust noise or a popping sound
Likely causes
- Rubbed through insulation letting the cylinder 8 injector wires touch each other
- Shorted winding inside the cylinder 8 injector
- Water or oil in the connector providing a leakage path between the terminals
- Loom pinched or melted where it passes close to the exhaust manifold
- Corroded or spread terminals no longer holding the pins securely
- Previous repair with unsuitable wire or poor insulation
- Injector driver in the module damaged by the shorted circuit
How to fix it
- Check misfire counters and confirm cylinder 8 is the affected cylinder
- Disconnect the injector and examine the connector for contamination, corrosion and heat damage
- Measure the injector winding resistance and compare it with the other cylinders
- Test the two wires for a short to each other and for insulation to ground with both ends disconnected
- Trace the harness for chafe or heat damage near the exhaust and along brackets
- Fit a known good injector in cylinder 8 to confirm whether the injector or the wiring is at fault
- Repair the harness or replace the injector, then clear the code and confirm balanced cylinder contribution after a road test