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GTECH Calibration
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P1272

Cylinder 2 High To Low Side Open.

  • Lincoln
  • Powertrain
  • Manufacturer code
  • Medium severity

How this code is built

P
SystemPowertrain
1
Defined byThe manufacturer
2
AreaFuel and air metering (injector circuit)
72
FaultThe specific fault in that area

What it means

On Lincoln models P1272 means the control unit has detected an open circuit between the high side and low side of the cylinder 2 injector circuit. The module monitors the injector driver and its wiring, and it set the code because the circuit did not show the expected electrical load or current. The exact circuit layout and test values depend on the model and engine, so check the manufacturer data for the vehicle.

Symptoms

  • Engine misfire or rough running, particularly on one cylinder
  • Illuminated engine warning light
  • Loss of power or poor acceleration
  • Hard starting or long cranking
  • Rough idle and increased fuel consumption
  • Possible fuel smell or raw fuel in the exhaust if the injector is stuck open

Possible causes

  • Open circuit or high resistance in the cylinder 2 injector wiring (broken, chafed or corroded wire)likely
  • Poor connection or corroded terminals at the cylinder 2 injector connectorlikely
  • Faulty cylinder 2 injector with an open internal coillikely
  • Damaged harness section or connector between the injector and the control unit, for example from heat or vibrationpossible
  • Poor connection at the control unit connector or a damaged pinpossible
  • Fault in the injector driver inside the control unitrare

How to diagnose

  1. Read all stored and pending codes and note the freeze frame data, then check for related misfire or other injector codes.
  2. Check for any technical service bulletins or software updates for the vehicle and engine.
  3. Visually inspect the cylinder 2 injector connector and harness for damage, heat marks, chafing, corrosion or loose terminals.
  4. Disconnect the injector connector and check the terminals for tightness and contamination.
  5. Measure the injector coil resistance and compare it with the manufacturer specification for that engine.
  6. With the connector disconnected, test the wiring from the injector to the control unit for continuity, and for shorts to ground or power, using the wiring diagram.
  7. Swap the injector with another cylinder, if the design allows, and see whether the fault follows it.
  8. If the injector and wiring are good, check the control unit connector and power and ground supplies before suspecting the control unit.

How to fix

  • Repair or replace the damaged section of wiring, using proper soldered and sealed joints.
  • Clean or replace corroded or loose connector terminals, or replace the connector.
  • Replace the cylinder 2 injector if its coil is open or out of specification.
  • Repair the control unit connector or terminal faults found during testing.
  • Replace or repair the control unit only after all wiring and injector faults are ruled out, and then carry out any required programming.
  • Clear the codes and road test to confirm the fault does not return.

Can I keep driving?

Medium severity

The car can usually be driven carefully for a short time, but one cylinder is probably not firing, which can cause poor running and strain the catalytic converter. Avoid heavy loads and book the repair soon, and stop driving if the misfire is severe or the warning light flashes.

Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.

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