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P1106

Dual Alternator Lower Fault Manifold Absolute Pressure (MAP) Sensor Circuit Intermittent High Voltage.

  • Ford
  • Powertrain
  • Manufacturer code
  • Medium severity

How this code is built

P
SystemPowertrain
1
Defined byThe manufacturer
1
AreaFuel and air metering
06
FaultThe specific fault in that area

What it means

On Ford, P1106 is listed as an intermittent high voltage fault in the Manifold Absolute Pressure (MAP) sensor circuit. The listed wording also mentions a dual alternator lower fault, which only applies to certain models, so check the exact definition for your model and engine. The engine control unit saw the MAP signal voltage briefly go higher than expected, then return to normal, so the fault comes and goes.

Symptoms

  • Engine warning light on
  • Intermittent hesitation or surging under load
  • Rough or unstable idle at times
  • Poor fuel economy
  • Occasional hard starting or stalling
  • Intermittent loss of power or black smoke on some engines

Possible causes

  • Loose, corroded or damaged connector at the MAP sensorlikely
  • Chafed, broken or intermittently shorted wiring in the signal, reference or ground circuitlikely
  • Failing MAP sensor giving an intermittent high signallikely
  • Poor sensor ground or reference voltage supply faultpossible
  • Vacuum or boost hose to the sensor split, blocked or loosepossible
  • Charging system or alternator fault causing electrical noise or supply voltage problems (relevant on models with dual alternators)possible
  • Fault inside the engine control unitrare

How to diagnose

  1. Read all stored and pending codes and note the freeze frame data, such as engine load, speed and temperature, when the fault set.
  2. Check for other related codes, especially other sensor circuit, charging system or reference voltage faults.
  3. Inspect the MAP sensor connector and wiring for corrosion, bent or pushed-back pins, chafing and heat damage.
  4. With the engine running, wiggle the connector and harness while watching live MAP data for sudden spikes or dropouts.
  5. Compare MAP reading with key on, engine off against local atmospheric pressure, then check it responds smoothly to throttle and boost or vacuum changes.
  6. Check the sensor's reference voltage, signal and ground against the wiring diagram for your model and engine.
  7. Inspect the sensor's vacuum or pressure hose and its seal for splits, blockage or air leaks.
  8. Test battery and charging output, including each alternator if fitted, and check for supply or earth faults.

How to fix

  • Clean, repair or replace the damaged connector or terminals at the MAP sensor.
  • Repair or replace any damaged wiring in the signal, reference or ground circuit.
  • Replace the MAP sensor if it gives an erratic or out-of-range signal.
  • Replace split, loose or blocked hoses and seals to the sensor.
  • Repair the charging system or earth connections if the supply voltage is unstable.
  • If the control unit is faulty, it should be diagnosed, repaired or replaced only after all other causes are ruled out.

Can I keep driving?

Medium severity

The car can usually be driven for a short time, but the fault may cause poor running and worse economy and could get worse. Book a diagnosis soon, and avoid heavy loads if the engine hesitates or stalls.

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

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