P0342
Camshaft Position Sensor A Circuit Low Input (Bank 1)P0342 is a generic OBD-II powertrain diagnostic trouble code: Camshaft Position Sensor A Circuit Low Input (Bank 1). It is logged by the engine control unit when the ckp/cmp monitor detects that a specific fault threshold has been exceeded — typically resulting in the malfunction-indicator lamp (MIL / check-engine light) being illuminated.
What P0342 means
P0342 is logged when the ECM detects that the voltage signal from Camshaft Position Sensor 'A' on Bank 1 is stuck at or below the minimum expected threshold. Most modern camshaft position sensors use a Hall-effect element that switches between a low voltage (near 0 V) and a reference voltage (typically 5 V) as the cam reluctor teeth pass. A signal fixed at the low state — due to an open circuit, short to ground, or failed sensor — is what sets P0342.
The camshaft position signal is used in conjunction with the crankshaft sensor to confirm which stroke each cylinder is on, enabling sequential fuel injection and correct ignition timing. Many engines can limp home using crank-only synchronisation, but cold starts and hot-restart behaviour are typically affected because cam-phase data is unavailable for prompt start strategies.
The most frequent cause is a damaged or oil-contaminated wiring harness near the sensor — a leaking valve cover gasket is a classic contributor, as oil can wick into the connector and corrode the terminals. A failed sensor itself, a stretched timing chain distorting the cam signal pattern, or low system voltage can also trigger this fault.
Common causes
Most-frequently reported root causes when P0342 is logged.
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1
Faulty camshaft position sensor 'A' on Bank 1 (failed Hall-effect element or open internal circuit).
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2
Short to ground in the sensor signal wire, holding the output at near 0 V.
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3
Open circuit in the sensor signal, power supply, or ground wire — including corroded or pushed-back connector pins.
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4
Oil contamination of the sensor connector from a leaking valve cover gasket.
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5
Stretched or jumped timing chain causing the cam reluctor to present an irregular or absent pulse pattern.
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6
Damaged cam reluctor wheel (missing or broken teeth).
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7
Low battery voltage or charging system fault producing insufficient reference voltage to the sensor.
Symptoms drivers notice
How to diagnose P0342
A typical diagnostic flow when this code is present.
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1
Scan for all stored codes and freeze-frame data; related crankshaft sensor or timing codes may indicate a mechanical (timing chain) root cause.
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2
Visually inspect the camshaft position sensor connector and harness for oil contamination, corrosion, broken wires, or cracked insulation — check for evidence of a leaking valve cover gasket nearby.
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3
With the ignition on and engine off, verify the sensor receives correct reference voltage (typically 5 V) and a clean ground at the connector.
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4
Using a multimeter or oscilloscope, confirm the signal wire is not shorted to ground (resistance to chassis ground should be very high with sensor disconnected).
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5
Start the engine and monitor the camshaft position sensor live data with a scan tool; a healthy Hall-effect signal should switch cleanly between 0 V and reference voltage as the engine cranks.
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6
If wiring checks out, replace the camshaft position sensor with an OEM-equivalent part and retest.
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7
If the code persists after sensor replacement, inspect the cam reluctor wheel and timing chain for mechanical wear.
Related powertrain codes
- P000A — A Camshaft Position Slow Response Bank 1
- P000B — B Camshaft Position Slow Response Bank 1
- P000C — A Camshaft Position Slow Response Bank 2
- P000D — B Camshaft Position Slow Response Bank 2
- P0010 — A Camshaft Position Actuator Circuit (Bank 1)
- P0011 — A Camshaft Position - Timing Over-Advanced or System Performance (Bank 1)
Frequently asked questions
Can the engine start at all with P0342?
Often yes — many ECMs fall back to crankshaft-only synchronisation and allow the engine to start and run, though with degraded timing accuracy. Hot-start conditions are typically worse because the ECM relies more heavily on cam phase data once it has learned engine parameters.
What is the difference between P0342 and P0341?
P0341 indicates the camshaft sensor signal is present but out of the expected range (intermittent or phase-correlation error), often pointing to a timing chain or reluctor issue. P0342 means the signal is stuck low continuously, which is more characteristic of a wiring or sensor failure.
Could a leaking valve cover gasket really cause this code?
Yes — it is one of the most common real-world causes. Oil seeping down the cylinder head can pool in the camshaft sensor connector, corroding the terminals and increasing resistance or breaking the circuit entirely. Replacing the gasket and cleaning or replacing the connector often resolves recurring P0342 faults.
How do I tell if the timing chain is the cause rather than the sensor?
Check for companion codes such as P0016 or P0017 (cam-crank correlation), listen for a rattling noise on cold start, and examine cam sensor waveform shape with an oscilloscope. A stretched chain shows a healthy signal voltage swing but with incorrect phase timing relative to the crank signal.
Disabling P0342 in software
RaceTune can permanently disable P0342 — and any other OBD-II diagnostic trouble code — on every ECU family we support. The monitor is disabled inside the ECU itself, so the fault stops being logged: the warning light stays off and the engine never enters limp mode for this code. The change is tied to your exact software version.
Software modifications affect emissions compliance and are not road-legal in many jurisdictions. RaceTune service files are intended for motorsport, off-road, and export use.
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