P065B

Symptoms

• Check Engine light comes on
• Unstable on-board voltage
• Slow battery drain
• Unstable lighting brightness under variable load
• Charging system warnings

Causes

• Wear of internal components of the generator (brushes, bearings, diode bridge)
• Lost communication via the control bus (LIN/CAN) between the ECU and the generator
• Incorrect operation of the voltage regulator with intelligent control
• Alternator drive belt slipping
• External load distorting generator response

How to Fix

1. Activate generator control commands through a professional scanner and check the response
2. Check voltage under different control commands (50%, 100% load)
3. Inspect the alternator belt and tensioner
4. Carry out a generator load test
5. Check the communication bus between the ECU and the generator
6. If confirmed - replacement or repair of the generator

Related codes

Error P065B by Vehicle Brand