Vito w638 doesnt start
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Vito w638 doesnt start
Hello. Let's see if someone can help us with a similar experience.
The battery warning light came on halfway home. As we got closer to home, all the warning lights came on and the car shut off. We managed to start it several times to check. It would start, but the battery wasn’t charging.
We changed the alternator, started the car, and everything was fine. It began charging at 14V. We started it several times, left it running for an hour, took it for a drive. Then we turned it off — and it wouldn't start again.
When we turn the key, the starter motor works, the engine turns, but it doesn’t start.
During testing, the temperature was fine at 80°C. The battery warning light went off.
We bled the air out.
The engine is an OM 611.
It’s a Vito W638 112 CDI 2.2.
We tried starting it with another car for half an hour.
We checked all the fuses and relays.
We bought a diagnostic tool. It shows errors B1040, B1041, B1043, B1010, B1301, B0004, B1115.
We checked the temperature sensors and thermostat, and they are working fine.
Someone recommended disconnecting the battery for half an hour and bridging the positive and negative cables to reset the ECU.
After doing that, the radiator fan turned on and the oil lamp warning light came on.
Using the diagnostic tool, we cleared an error, and the radiator fan and oil lamp warning light turned off.
After several attempts to start the car, now when we turn the key, the dashboard lights up but nothing happens.
Also, the radiator fan turned on again.
The battery warning light came on halfway home. As we got closer to home, all the warning lights came on and the car shut off. We managed to start it several times to check. It would start, but the battery wasn’t charging.
We changed the alternator, started the car, and everything was fine. It began charging at 14V. We started it several times, left it running for an hour, took it for a drive. Then we turned it off — and it wouldn't start again.
When we turn the key, the starter motor works, the engine turns, but it doesn’t start.
During testing, the temperature was fine at 80°C. The battery warning light went off.
We bled the air out.
The engine is an OM 611.
It’s a Vito W638 112 CDI 2.2.
We tried starting it with another car for half an hour.
We checked all the fuses and relays.
We bought a diagnostic tool. It shows errors B1040, B1041, B1043, B1010, B1301, B0004, B1115.
We checked the temperature sensors and thermostat, and they are working fine.
Someone recommended disconnecting the battery for half an hour and bridging the positive and negative cables to reset the ECU.
After doing that, the radiator fan turned on and the oil lamp warning light came on.
Using the diagnostic tool, we cleared an error, and the radiator fan and oil lamp warning light turned off.
After several attempts to start the car, now when we turn the key, the dashboard lights up but nothing happens.
Also, the radiator fan turned on again.
Member
Joined: Jun 2024
Posts: 191
Likes: 58
E320
That sounds like a frustrating situation, but based on what you described, I’d look closely at an issue with the ECU not waking up properly or a CAN communication fault between the key/immobilizer system and the engine control module. When you turn the key and nothing happens despite the dash lighting up, it usually means the ECU isn’t authorizing start — even if the starter turns or the relays click.
The fact that the radiator fan kicks on and stays on along with the oil warning light is another clue. That’s a typical “safe mode” behavior when the ECU either loses communication with critical sensors or doesn’t get proper voltage. Those codes you pulled — especially B1040, B1041, B1043, B1010, B1301 — all suggest either low voltage, corrupted memory, or possibly a fault in the SAM (Signal Acquisition Module) or immobilizer circuit.
Since you already replaced the alternator and verified battery charging, I’d suggest checking the ground connections very closely — especially the ECU ground and chassis-to-engine straps. You’d be surprised how often these cause starting issues after electrical repairs. Also, make sure none of the fuses or relays are heat-cycled or slightly loose — particularly K40 relay module if it’s used on your model. This is definitely the type of issue where a full-system scan is essential. I’ve had great success using the YOUCANIC full system scanner for this kind of thing. It reads codes from every control unit, including the immobilizer and SAM, and lets you monitor real-time data to see if the ECU is even seeing the start request or if the CAN network is waking up properly. It's a powerful tool when you’re chasing intermittent no-start problems like this.
The fact that the radiator fan kicks on and stays on along with the oil warning light is another clue. That’s a typical “safe mode” behavior when the ECU either loses communication with critical sensors or doesn’t get proper voltage. Those codes you pulled — especially B1040, B1041, B1043, B1010, B1301 — all suggest either low voltage, corrupted memory, or possibly a fault in the SAM (Signal Acquisition Module) or immobilizer circuit.
Since you already replaced the alternator and verified battery charging, I’d suggest checking the ground connections very closely — especially the ECU ground and chassis-to-engine straps. You’d be surprised how often these cause starting issues after electrical repairs. Also, make sure none of the fuses or relays are heat-cycled or slightly loose — particularly K40 relay module if it’s used on your model. This is definitely the type of issue where a full-system scan is essential. I’ve had great success using the YOUCANIC full system scanner for this kind of thing. It reads codes from every control unit, including the immobilizer and SAM, and lets you monitor real-time data to see if the ECU is even seeing the start request or if the CAN network is waking up properly. It's a powerful tool when you’re chasing intermittent no-start problems like this.
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