P0342 — Cam Position Sensor Low Input (Bank 1)

What does P0342 mean?

P0342 is set when the ECM sees the Bank 1 "A" camshaft position sensor circuit sitting below its calibrated minimum voltage. On most engines "A" is the intake camshaft, or the single cam sensor on engines that only have one. The usual explanation is a signal wire shorted to ground, an open circuit that lets the ECM's internal pull-down hold the line low, or a sensor that has failed to a low output. P0342 is a voltage-level fault — distinct from P0340 (no usable signal) and P0341 (signal present but out of spec).

What are the symptoms of P0342?

• Check Engine Light is illuminated
• Hard start with extended cranking
• Possible complete no-start condition
• Stalling, often when the engine is hot
• Rough running and noticeably reduced power
• Misfire-like stumbling if the ECM loses cylinder sync
• Reduced fuel economy

What causes P0342?

Repair costs are typical US ranges and vary by make, model, model year, and labor rate. A diagnostic trouble code is a symptom, not a guaranteed failed part — confirm the root cause before replacing anything.

Is it safe to drive with P0342?

In most cases a vehicle stays drivable for short trips with P0342 active, but you should diagnose and repair it promptly. This is a high-severity code — ignoring it can lead to further damage or a failed emissions test. Exact tolerance depends on your specific make and model.

How to diagnose P0342

1. Inspect the connector and harness at the cam sensor

   The cam sensor usually threads into the cylinder head or the timing cover near the front of the engine. Unplug it and look for corrosion, spread or pushed-back pins, oil inside the connector body, and chafe marks where the harness passes a bracket. Fix what you find before testing further — a marginal connector produces exactly this code.

   Tools: Connector unlock tool, Flashlight, Electrical contact cleaner

2. Back-probe the signal wire with the key on

   With the sensor still connected and the key on, engine off, measure the signal wire against a good ground. A Hall-effect cam sensor normally rests high (near reference voltage) and pulls low as the reluctor passes. A signal line sitting at or near zero volts with the key on is the condition that sets P0342.

   Tools: Multimeter, Back-probe pins, Wiring diagram

3. Run the disconnect test to split sensor from wiring

   Unplug the sensor and measure the signal wire at the harness side, key on. If the voltage now rises to the ECM's reference level, the wiring is fine and the sensor was pulling it down — replace the sensor. If it stays pinned low with the sensor unplugged, the short to ground is in the harness, and a new sensor will change nothing.

   Tools: Multimeter, Wiring diagram

4. Verify sensor power and ground

   With the connector unplugged and the key on, confirm the supply voltage the wiring diagram calls for on the power pin, and a clean low-resistance path from the ground pin to chassis ground. A corroded ground makes a good sensor read low and sets P0342 with no fault in the sensor at all.

   Tools: Multimeter, Wiring diagram

5. Scope the sensor while cranking

   If the static tests all pass, capture the waveform during a crank. A healthy Hall sensor produces clean square pulses at consistent spacing. Pulses that are present but clipped low, or a trace that never leaves the baseline, confirm the sensor or its supply. Compare against the known-good waveform in the service manual.

   Tools: Oscilloscope, Back-probe pins

How do I fix P0342?

• Replace the camshaft position sensor with an OEM part
• Repair the shorted-to-ground signal wire
• Repair or replace the corroded sensor connector
• Replace the cam sensor o-ring to stop oil intrusion
• Replace a damaged or slipped cam reluctor wheel

P0342 by make and model

Select your exact year, make, and model below to get a P0342 diagnosis tuned to your vehicle's known failure patterns, recalls, and TSBs.

Related diagnostic codes

• P0340 — Camshaft Position Sensor Circuit Fault
• P0341 — Camshaft Position Sensor Range / Performance
• P0343 — Cam Position Sensor High Input (Bank 1)
• P0345 — Camshaft Position Sensor Circuit (Bank 2)
• P0016 — Crank/Cam Correlation Fault (Bank 1 Intake)
• P0335 — Crankshaft Position Sensor Circuit Fault

Common symptoms of P0342

P0342 often shows up as one of these symptoms. Start from what your car is actually doing:

• Hard starting / long crank
• Engine stalling
• Reduced engine power / limp mode
• Engine vibration or shaking