DTC Atlas
Atlas / DTC Atlas / P0343
P0343Powertrain
Powertrain · SAE
CMP Sensor — High Input

Meaning

The engine control module has detected that the camshaft position (CMP) sensor signal is consistently above the maximum allowed threshold. The circuit exhibits excessive voltage or signal amplitude, indicating a short to power, external induction, or an internal sensor failure.

Common causes

  • CMP sensor signal wire shorted to reference voltage (5 V) or battery positive
  • Faulty CMP sensor with abnormally high voltage output
  • Induction from adjacent high-voltage wiring (ignition or alternator)
  • Sensor connector swapped or connected to the wrong circuit
  • Defective internal pull-up resistor in the ECM
  • Moisture contamination in the connector creating a resistive path to supply

Symptoms

  • Check-engine light (MIL) illuminated
  • Hard start or no-start
  • Disrupted sequential injection with engine instability
  • Possible fixed or implausible camshaft position reading
  • Rough idle

Severity

High: a saturated CMP signal prevents the ECM from determining camshaft position; sequential injection synchronization is compromised.

What to do

  1. Measure voltage on the CMP signal wire with ignition ON and engine stopped
  2. Check for short to supply voltage on the signal wire
  3. Inspect wiring insulation against adjacent high-voltage circuits
  4. Check the connector for moisture, corrosion, or internal short circuits
  5. Replace the CMP sensor if wiring is found serviceable

Format conversion

SAEP0343
HEX0343
VAG00835
Open in the DTC converter →