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P1222

Injector Control Circuit Intermittent.

  • Chrysler
  • Powertrain
  • Manufacturer code
  • Medium severity

How this code is built

P
SystemPowertrain
1
Defined byThe manufacturer
2
AreaFuel and air metering (injector circuit)
22
FaultThe specific fault in that area

What it means

On Chrysler vehicles P1222 means the engine control unit has detected an intermittent fault in an injector control circuit. The unit monitors the injector driver circuit and saw a signal that dropped out, was erratic or did not match the commanded state, but not constantly enough to be a permanent open or short. Which injector or bank is covered depends on the model and engine, so confirm this against the vehicle-specific data.

Symptoms

  • Engine misfire or rough running that comes and goes
  • Hesitation or stumbling under acceleration
  • Intermittent hard starting or occasional long cranking
  • Engine management warning light on
  • Occasional stalling or reduced power
  • Poor fuel economy

Possible causes

  • Loose, corroded or damaged connector at an injector or the harness pluglikely
  • Chafed, broken or intermittently shorting wiring in the injector control circuitlikely
  • Faulty fuel injector with failing internal winding that varies with heatpossible
  • Poor power or earth supply to the injector circuit or engine control unitpossible
  • Pin fitment problems or terminal fretting in the engine control unit connectorpossible
  • Internal fault in the engine control unit injector driverrare

How to diagnose

  1. Read all stored and pending codes and record the freeze frame data, noting engine temperature, load and speed when the fault set
  2. Check for related misfire codes or other injector circuit codes to see which cylinder or bank is involved
  3. Visually inspect the injector connectors, harness routing and wiring near hot or moving parts for chafing, heat damage, oil contamination or corrosion
  4. Wiggle test the harness and connectors with the engine running or on live data, watching for a change in idle quality or the fault resetting
  5. Measure injector winding resistance and compare it with the manufacturer specification for that engine, testing both cold and warm
  6. Check the injector control circuit for continuity, short to earth and short to supply between the injector and the control unit connector
  7. Check the battery voltage, fuses, relays and the power and earth connections feeding the injectors and the control unit
  8. Use an injector pulse test (oscilloscope or noid-style check) to confirm the control unit is driving the circuit correctly

How to fix

  • Clean, reseat or replace damaged injector connectors and terminals
  • Repair or replace the damaged section of wiring in the injector control circuit, using proper soldered and sealed repairs
  • Replace any injector whose resistance or operation is out of specification
  • Restore faulty power or earth connections and replace any failed fuse or relay
  • Repair or replace the control unit connector terminals if they are damaged or fretted
  • Replace or have the engine control unit repaired only after wiring and injectors are proven good and the driver fault is confirmed

Can I keep driving?

Medium severity

The car can usually be driven short distances, but intermittent injector faults can cause misfires, stalling and unburnt fuel reaching the catalytic converter. Get it diagnosed soon, and avoid heavy loads if it is misfiring.

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

This code for other makes

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