Fault code P0650 – a step-by-step guide to diagnosing and fixing it

Error code P0650 is displayed and the check engine light is on - what does this mean?

The OBD/EOBD system detects a fault in the Malfunction Indicator Lamp (MIL) Control Circuit, i.e. in the control circuit of the check engine light itself. This DTC P0650 indicates problems with the wiring, the control module or the indicator lamp, which is responsible for the display of other error codes.

What can cause this fault code?

• Defective engine indicator lamp (MIL)
• Damaged wiring to the MIL control circuit
• Loose or corroded plug connections
• Defective engine control unit (ECM/PCM)
• Short circuit in the MIL circuit
• Interrupted ground connection
• Faulty instrument panel
• Faulty fuse in the MIL circuit

What symptoms occur in parallel with fault code P0650?

• Check Engine Light does not work: The Check Engine Light does not illuminate, although other fault codes may be present
• Intermittent light function: The MIL flickers or lights up irregularly
• Complete failure of the check engine light: The check engine light remains permanently off
• Other warning lights affected: Other warning lights may not be functioning properly
• No visual symptoms on the engine: The engine runs normally as fault code P0650 only affects the indicator components

How can I fix the problem with fault code P0650?

• Repairing trouble code P0650 requires a systematic diagnosis of the MIL control unit.
• Checking and replacing the defective check engine light in the instrument panel if it is burnt out or mechanically damaged
• Check all wiring and plug connections to the MIL control circuit for damage, corrosion or loose contacts and repair accordingly
• Replacement of the engine control unit (ECM/PCM) if the internal MIL control circuit is defective and other components are functional
• Repair or replacement of the entire instrument panel if the MIL control board is damaged
• Checking and replacing the associated fuses in the MIL circuit
• Repair of short circuits or breaks in the wiring between the ECM and the instrument panel