P0622

Symptoms

• Check Engine Light and Battery Light Come On
• Battery not charging or charging at maximum voltage
• Rapid battery drain
• Battery overheating due to constant recharging
• Electronics malfunction due to unstable voltage

Causes

• Open or short circuit in the field winding circuit
• Faulty generator voltage regulator
• Broken wire terminal F between the generator and the computer
• Oxidation of the generator connector
• Internal malfunction of the generator field winding

How to Fix

1. Measure the charging voltage with the engine running (normal 13.8–14.4 V)
2. Check the terminal F wire from the generator to the ECU for open and short circuits.
3. Measure the resistance of the field winding (the norm is 2–5 Ohms depending on the brand)
4. Check the voltage regulator - measure the control signal at terminal F
5. If the winding breaks, replace the generator or rewind the winding
6. If the generator is working, ECU diagnostics

Related codes

Error P0622 by Vehicle Brand