HomeTrouble CodesP1174

P1174 — Cam Sensor Fault

Manufacturer-specificPowertrain (engine & transmission)

OBD-II code P1174 indicates a malfunction within the camshaft position sensor circuit or an implausible signal from the sensor itself. This code suggests the engine control module cannot accurately determine the camshaft's position relative to the crankshaft, which is critical for ignition timing and fuel injection synchronization.

Symptoms

What causes it — most likely first

1. Failed camshaft position sensor

The internal electronics of the sensor often degrade over time due to heat exposure, causing intermittent or total signal loss.

2. Damaged wiring or connectors

Wiring harnesses near the engine block can suffer from heat damage, chafing, or corrosion at the connector pins, interrupting the signal path.

3. Excessive camshaft bearing wear

Mechanical wear in the camshaft bearings can allow excessive play, altering the gap between the sensor and the reluctor wheel and causing erratic readings.

4. Damaged reluctor wheel

The toothed wheel on the camshaft that the sensor reads may be cracked, missing teeth, or covered in metallic debris, preventing accurate position detection.

5. Timing chain or belt issues

If the timing component has stretched or jumped a tooth, the correlation between the crankshaft and camshaft positions will fall outside acceptable parameters.

6. Faulty engine control module (PCM)

While rare, the internal processor or input circuit within the PCM may fail to process a valid sensor signal, though this is typically a last-resort diagnosis.

How it's diagnosed

  1. Inspect the camshaft position sensor wiring harness and connector for signs of melting, fraying, corrosion, or loose pins.
  2. Measure the sensor's resistance and reference voltage using a multimeter to verify values match manufacturer specifications.
  3. Use an oscilloscope to view the sensor's AC or digital waveform while cranking the engine to check for signal dropouts or irregular patterns.
  4. Visually inspect the reluctor wheel through the sensor mounting hole or by removing the valve cover to check for damage or debris.
  5. Check camshaft end-play and bearing condition to ensure mechanical stability is not affecting the sensor air gap.
  6. Swap the sensor with a known good unit to confirm if the fault follows the component before considering PCM testing.

Code facts & related codes

SystemPowertrain (engine & transmission)
StandardizationManufacturer-specific (P1/B1/C1/U1)
Related codes

Frequently asked

Is it safe to drive with a P1174 code?

It is generally not recommended, as the engine may stall unexpectedly, lose power, or fail to restart, creating a safety hazard.

Will replacing the PCM fix a P1174 code?

No, replacing the PCM is rarely the solution for this code; the fault is almost always located in the sensor, wiring, or mechanical timing components.

Can bad oil cause a P1174 code?

Yes, sludge or metallic debris in the oil can coat the sensor tip or damage the reluctor wheel, leading to signal interference.

Why does the car start fine when cold but not when hot?

Heat-sensitive internal failures in the sensor or expanding wiring cracks due to thermal stress often cause intermittent faults that appear only at operating temperature.