Code
P1173
FORD
P — Powertrain
Rotor Calibration Fault
Views:
UK: 24
EN: 58
RU: 46
AI status
Completed
Completed
100%
Causes
- Faulty rotor position sensor (Hall or magnetic reluctor)
- Damaged or misaligned rotor/reluctor assembly
- Wiring problem (open, short, corrosion, damaged shield) between sensor and PCM
- Poor or intermittent sensor power or ground
- Incorrect rotor installation or mechanical timing error
- Connector contamination or bent pins
Symptoms
- MIL/Check Engine lamp illuminated
- Engine may be hard to start or will not start
- Misfires, rough idle or poor running at low RPM
- Stalling or intermittent loss of driveability
- No or abnormal reference pulses in scan tool/oscilloscope data
What to check
- Read freeze frame and live data with a capable Ford scan tool (IDS) and note stored/snapshot parameters
- Check for additional related DTCs (crank/cam position codes)
- Visually inspect rotor/reluctor, sensor and surrounding area for damage, oil/debris or physical misalignment
- Inspect sensor connector for corrosion, bent pins, water intrusion and secure mating
- Backprobe sensor connector to verify reference voltage (usually 5 V for Hall sensors) and good ground
- Check wiring continuity and resistance between sensor and PCM; wiggle harness while monitoring for intermittent changes
Signal parameters
- Hall-effect sensor: digital switching between ~0 V and ~5 V corresponding to rotor teeth/poles
- Magnetic (inductive) sensor: AC waveform amplitude increases with RPM; typical amplitude range 0.2–10 V peak depending on sensor and speed
- Reference pulse frequency proportional to engine RPM; compare pulses per crank revolution to factory specification
- Signal duty/phase should align with crank/cam reference pulses; any missing/extra pulses or phase shift indicates calibration or mechanical timing issue
Diagnostic algorithm
- Retrieve all stored codes and freeze frame data. Note related crank/cam or ignition codes. Clear codes and attempt to recreate.
- Perform a visual inspection of rotor/reluctor, sensor, mounting, and harness. Repair obvious damage/corrosion.
- Verify sensor supply (reference) and ground at the connector with key ON. If missing, trace and repair power/ground circuit.
- With engine cranking or running, monitor sensor signal with a scan tool and oscilloscope. Look for missing pulses, distorted waveform, low amplitude or noise.
- Check continuity and resistance of wiring between sensor and PCM; repair any short/open or corrosion.
- Confirm rotor orientation and mechanical timing/position per Ford service manual; correct if rotor installed incorrectly or timing slipped.
- If wiring and mechanical parts are good, replace the rotor position sensor (or rotor/reluctor) and retest.
- If fault persists after component replacement and wiring checks, check for required PCM software updates or consult manufacturer service information; consider PCM replacement only after other causes eliminated.
- Clear codes and perform a road test/functional test while monitoring live data to confirm normal rotor calibration and disappearance of fault.
Likely causes
- Damaged or misaligned rotor/reluctor assembly
- Faulty rotor position (reference) sensor
- Wiring/connector fault (corrosion, broken wire, poor ground)
- Incorrect installation or timing after service
Fault status
Status
P1173 - Rotor Calibration Fault: Module detected rotor position/calibration error (reference pulses or timing out of specification).
Repair difficulty: Medium
Diagnostic time: 1.0-2.5 hours
Similar codes
Your experience will help others
+100 karma for a short comment :)
Was this AI description helpful?
Your feedback helps improve AI descriptions.
👍 Like
0
👎 Dislike
0
Send to email