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DTC codes / Ford codes / P1268

P1268 · FordCylinder 8 High To Low Side Short

P1268 on Ford vehicles means the powertrain control module (PCM) has detected an electrical short between the high-side and low-side circuits for fuel injector number 8. The PCM monitors injector circuit voltage and flags this code when the command signal and return path are shorted together, which prevents normal injector operation.

SystemPowertrain
Code typeFord specific
SeverityMedium
Fix difficultyIntermediate
AreaFuel and air metering (injector circuits)

Symptoms you may notice

  • Rough running or misfire, especially noticeable at idle or under light load
  • Check engine light illuminated, often with a flashing condition if the misfire is severe
  • Reduced engine power or limp mode in some Ford models
  • Poor fuel economy and increased emissions
  • Often no symptoms besides the warning light if the short is intermittent
  • Possible engine vibration or shaking felt through the steering wheel and seat

Common causes, most likely first

  1. Chafed or damaged injector wiring harness between the PCM and cylinder 8 injector
  2. Internal short inside the cylinder 8 fuel injector solenoid
  3. Corroded or loose connector pins at the injector or PCM
  4. Short to ground or short between the high and low side wires in the engine harness
  5. Failed PCM driver circuit for injector 8 (less common)
  6. Aftermarket accessories or previous repairs that pinched or rerouted the injector harness

How to diagnose and fix it

  1. Inspect the cylinder 8 injector connector and wiring for visible damage, corrosion, or chafing
  2. Disconnect the injector and measure resistance across the injector terminals to check for an internal short
  3. Check for continuity between the high-side and low-side injector wires at the PCM connector to confirm a harness short
  4. Wiggle-test the harness while monitoring injector circuit voltage with a scan tool to catch intermittent shorts
  5. Repair or replace the damaged section of the injector harness or connector
  6. Replace the cylinder 8 fuel injector if it is internally shorted
  7. Clear the code and perform a road test to verify the repair, reprogramming the PCM only if a driver fault is confirmed

Before you replace the cylinder 8 injector

  • A shorted injector coil can be caused by a failed injector, but a chafed harness rubbing against a bracket or valve cover is just as common on high-mileage Ford engines.
  • The PCM may set P1268 even when the injector still fires normally if the short is intermittent, so a wiggle test of the harness is essential before condemning parts.
  • Do not overlook the PCM connector pins; corrosion or a backed-out terminal can mimic a high-to-low side short and is often missed during a quick visual inspection.
  • This code can be stored alongside misfire codes for cylinder 8, but the misfire may be a symptom of the short rather than a separate ignition fault.
  • Aftermarket remote starters or alarm wiring tapped into the injector harness can introduce shorts that only appear when the accessory is active.

Can I keep driving with P1268?

You can drive cautiously to a repair shop if the engine runs smoothly and the check engine light is steady, but avoid heavy acceleration or towing. If the light is flashing or the engine misfires badly, stop driving to prevent catalytic converter damage.

Tools that help

Tools we recommend are in the Auto Veteran shop on Amazon. As an Amazon Associate we earn from qualifying purchases.

Guidance is general and written for Ford vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.

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