P0387

Symptoms

• The engine does not start or starts with great difficulty
• Unstable operation, frequent engine stops
• No spark or injection
• Check Engine Light Is On
• The ECU may go into emergency mode

Causes

• Short circuit of the sensor signal wire to ground
• No power supply to the sensor (open circuit)
• Air gap too large (sensor misaligned)
• Faulty sensor (internal failure)
• Sensor contamination blocking magnetic flux

How to Fix

1. Read error codes, check sensor parameters at idle
2. Check the sensor supply voltage (standard: 5V or 12V depending on the type)
3. Check the signal wire for short circuit to ground (resistance between signal and ground should be high)
4. Check the air gap between the sensor and the drive disk
5. Check the sensor with an oscilloscope while cranking with the starter
6. Replace crankshaft sensor B

Related codes

Error P0387 by Vehicle Brand