Multiple ECU-related faults; general ECU internal error logged; engine may not start or may run in limp mode.

Safety: Disable auto-start and isolate power before disconnecting ECU connectors.

• Inspect ECU housing: Check for signs of water ingress, cracks, or physical damage to the Volvo Penta ECU.
• Check power and ground quality: Verify that ECU supply voltage is stable and within spec, and that ground connections are clean and tight. Correct any wiring or grounding issues.
• Connector inspection: Disconnect ECU plugs and inspect for bent pins, corrosion, or moisture. Dry thoroughly and clean with contact cleaner, then reconnect securely.
• Software update: Use Volvo Penta diagnostic tools to check for available ECU software updates and reflash if recommended.
• Replace ECU if necessary: If internal faults persist after power/ground and software checks, the ECU may need replacement and programming by an authorized Volvo Penta dealer.