Code
P1190
LINCOLN
P — Powertrain
Calibration Resistor Out Of Range
Views:
UK: 20
EN: 36
RU: 32
AI status
Completed
Completed
100%
Causes
- Open or shorted calibration resistor inside sensor or harness
- Corroded, bent, or damaged connector pins or wiring (short to ground, short to Vref, or open)
- Incorrect or non‑OEM replacement sensor (wrong internal resistor value)
- Poor or missing ground or reference voltage to the sensor
- Intermittent connection (moisture, heat, vibration)
- Faulty PCM/ECU input circuit or internal calibration error
Symptoms
- Malfunction Indicator Lamp (MIL) illuminated and P1190 stored
- Incorrect gauge or sensor readout related to the affected sensor (e.g., temperature, pressure, level)
- Intermittent or poor engine performance if sensor affects engine control
- Hard starting or poor idle if sensor tied to fuel/ignition control
- No cranking or starting symptom only if the sensor is used for start strategy (vehicle specific)
What to check
- Scan vehicle and retrieve freeze frame and live data for the triggering sensor and related parameters
- Visually inspect sensor connector for corrosion, bent pins, water, or damage
- Check harness for physical damage, rubbing, or pinched sections between sensor and ECU
- Verify sensor ground(s) and reference supply (usually 5 V) at the connector with engine off and key on
- Measure sensor resistance with connector disconnected and compare to manufacturer specification
- Backprobe signal wire with a multimeter/scan tool to confirm signal voltage under varying conditions
Signal parameters
- Reference voltage (Vref): typically ~5.0 V (verify with vehicle spec)
- Sensor signal voltage: typically 0.1–4.9 V depending on sensor position/condition
- Expected resistor range: manufacturer-specific — commonly between ~1 kΩ and 100 kΩ for calibration resistors; refer to service data
- Open circuit: measured resistance = infinite (or very high)
- Short to ground: measured resistance ≈ 0 Ω or signal voltage ≈ 0.0–0.2 V
- Short to battery: signal voltage ≈ Vbatt (near 12 V) — abnormal for 5 V referenced circuits
Diagnostic algorithm
- Obtain full scan data, freeze frame, and any related codes. Note mileage and conditions when code set.
- Visually inspect the sensor and connector for corrosion, bent pins, water, or damage. Repair/clean as needed and clear codes to test.
- With ignition ON (engine OFF) verify Vref (usually 5 V) and ground at the sensor connector. If Vref or ground missing, trace back to ECU and repair wiring/ground.
- Disconnect sensor and measure internal calibration resistor value across specified pins with a multimeter. Compare to factory spec. If out of spec, replace sensor.
- If resistor reads OK, backprobe the signal wire and monitor voltage while operating the circuit (or while having assistant vary the sensed condition). Look for correct voltage range and for intermittent changes when wiggling harness.
- Perform continuity and resistance checks from sensor connector to the ECU connector to rule out high-resistance joints or shorts to ground/power. Repair any wiring faults.
- If wiring and sensor test good but code persists, inspect ECU connector for corrosion/damage. Consider swapping ECU or bench-testing only if all other causes excluded and per service manual.
- After repairs, clear codes and perform road/operational test to confirm code does not return and that sensor readings behave correctly.
Likely causes
- Damaged sensor with failed internal calibration resistor
- Connector corrosion or water intrusion causing high resistance or intermittent contact
- Broken or shorted wiring between sensor and ECU (rodent damage, chafing)
- Aftermarket sensor installed with incorrect resistance specification
- Faulty ECU input or blown protection component
Fault status
Status
Calibration resistor value outside allowable range for the specified sensor circuit. Possible open, short, incorrect component, wiring/connector fault, or ECU input failure.
Repair difficulty: Medium
Diagnostic time: 0.5-2.5 hours
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