P0642

Symptoms

• Check Engine light comes on
• Multiple sensor codes at once
• Unstable or low performance of MAP/TPS sensors
• Engine emergency mode
• Dips and jerks when moving

Causes

• Oxidation of ECU connectors or circuit A sensors
• Sensor with internal current leakage to ground
• High resistance in the circuit conductor (partial open)
• Dirt or moisture in the connectors
• Malfunction of the voltage reference circuit inside the ECU (rare)

How to Fix

1. Check circuit A sensor reference voltage (should be 4.9-5.1 V)
2. Inspect and clean all sensor connectors connected to circuit A
3. Disconnect the sensors one at a time to find the source of the voltage dip
4. Check the resistance of the reference voltage wire from the ECU to the sensors
5. Inspect the ECU connector for oxidation and moisture.
6. Replace the faulty sensor or repair the wiring

Related codes

Error P0642 by Vehicle Brand