MHD codes 2A61: Cranks but won’t start.

corp

///Member
Just an update:

Car was taken to an auto electrician trusted by CCD. Based on the information provided to them, they were told the car doesn’t start. Because the water pump kept running it drains the battery. They charged the battery and fix the water pump continually switching on by adding a relay on the line.

They drove the car around and had it idling a while. Initial issue of the motor cutting out and not starting didn’t return.

I test drove the car with one of the guys whilst they had the Launch software connected and monitoring the vehicle. Not a single fault when when it reached operating temperature.
CCD has replaced the thermostat that burnt out so the temp gauge on coolant seemed fine too on the readings.

I paid and left, drove about 50km to fetch my belly pan cover. The car did not want to start after stopping there. 2min later it started again.

I drove to the client, about 5km away, and the car stalled twice. Each time the half yellow engine light came on. I stopped the car and it started up immediately. Parked the car at my destination and let it idle. Car eventually stalled again and hen wouldn’t start. Same as last time, same codes appeared and the started later when the tow truck arrived.




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akash

Well-known member
Stupid question, do you have the car on a stock file at the moment or on a MHD file.
 

corp

///Member
As far as I am aware it is stock. CCD asked the same question cause one of their cars doesn’t start every few months and they just reflash.


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Ratslaaf

///Member
Two reasons why this happens:
1) the relay providing power to the injector PSU is buggered. Can be wiring also
2) the injector PSU itself is buggered inside the ecu.

These, and VVT failures, are not uncommon on mevd172 ecu as used on N55.

All the other heath Robinson kak they added to the water pump must be removed. The water pump runs like that, because the ecu isn’t going into sleep mode because of the fault.
 

corp

///Member
Ratslaaf said:
Two reasons why this happens:
1) the relay providing power to the injector PSU is buggered. Can be wiring also
2) the injector PSU itself is buggered inside the ecu.

These, and VVT failures, are not uncommon on mevd172 ecu as used on N55.

All the other heath Robinson kak they added to the water pump must be removed. The water pump runs like that, because the ecu isn’t going into sleep mode because of the fault.


I must admit, I was worried about the relay job stopping the electric motor from running unless ignition was switched on. That defeats the point of the electric water pump.

Are you able to assist with both these potential problems? Are they even “easy-ish” fixes?


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Ratslaaf

///Member
Eish bud, I’m afraid I don’t work on the actual cars. I do the ecu repair/replacement for the trade so only get the actual modules after the fault is diagnosed.

I would, however recommend you take your car to a reputable workshop. Easiest would be to swop out the ecu to try and isolate the fault. I don’t have stock on these at the moment for a swop (they also need to be aligned to the car), but PM me rather and let’s see what’s possible. For some reason your case rings a bell though...
 

corp

///Member
Yeah, we made quick contact last week. The car was then at a workshop that could not diagnose the problem and advised the car go to the auto electrician the use regularly.

Problem is the auto electrician didn’t have the right story when first looking at the car and fixing it so they didn’t find or look for this issue.

To avoid buying a new ECU, I am hoping the problems you mentioned are fixable though.





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Ratslaaf

///Member
lol Ok, I thought it sounded familiar. Give me a call again tomorrow, there’s a slight chance I might have a better answer than I had last week.
 

corp

///Member
So after some testing and fixes were performed, it was found that my one of my valvetronic relays was faulty which ended up being a major cause, potentially, for the stalling.


Once that was sorted, drove home and the stalling happened again. Not in the mood, Inleft the car until morning before I went looking for issues and found I had plenty additional errors codes. Whilst chatting to the guys about these extra errors, it was spotted that my battery is below spec. Only 70AH and 495CCA. Being that the battery drained a few times and all the new errors were moaning about voltage I replace the battery with a new bigger model. This sorted out all the additional errors that appeared.

There was however two new fault codes that kept coming up despite clearing them (car didn’t stall with them at all). 2A5F and 2F8A. Both spoke about a B+ short on the relay for injection/ignition or a supply voltage issue.

I decided to fiddle a bit of the weekend by relay under the hood and, unbeknown to me what happened, the car magically stopped having an faults codes.
Every trip it was fine, every start without fault so I imagine that last code had something to do with a loose/dirty connection somewhere.

The luck only last about 3 days though. Yesterday, in the morning only, the car didn’t start on first try and the original 2A61 and 371C fault codes returned. I cleared them, drove all day, in traffic, through heavy rain weather, pushed it a few times and each time the car was fine. Started again this morning and the same thing happened. Didn’t start first time and starts each time after that without fault codes.

Decided not to drive it today, cause I couldn’t risk not getting to places today, but I am not sure why these are back again and why only on cold morning starts.


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Ratslaaf

///Member
Bud, I just cannot help but suspect a shitty connection somewhere. If the ecu was buggered, it wouldn’t be intermittent like this. The fact that you messed with the wiring and it came right leads me to this as well.

I’ve had some issues where water got into these specific ECUs after guys had messed with the wiring. Best to remove all plugs going to the ecu and inspect them nicely for water ingress.
 

corp

///Member
That is not a bad idea to look for something along those lines. I am going to tackle that this weekend.


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Chris'

New member
corp said:
That is not a bad idea to look for something along those lines. I am going to tackle that this weekend.


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Any update on this? I have the exact same problem.

Id love to know
 
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