Engine Management Light Stays On - Intermittent

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sickonit
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Engine Management Light Stays On - Intermittent

Post by sickonit » Fri Nov 06, 2020 1:27 pm

Hi,

I'm a relative Bongo newbie having picked up my 2.0l 2004 Bongo in early Jan 2020 and I'm hoping somebody can help me.

I never had a problem with the MIL staying on until I had an alarm/immobiliser professionally fitted early Feb 2020. A few weeks after it was fitted we went out for a drive and stopped off somewhere and when we got back in the Bongo and started the engine the MIL stayed on all the way home.

The next time we went out in the vehicle the MIL did not stay on so I thought the fault had reset itself. However the number of times the MIL stayed on increased over the next few weeks until it was on 75% of the times we used the vehicle. I contacted the alarm fitter and he said that the EMS thinks that the immobiliser is interfering with the electrics and so produces a fault. He said the fault will clear itself. Well it didn't and during the 1st lockdown we hardly went out in the vehicle so I did nothing about it.

I have this week bought a Clarke OBDII diagnostic reader and I cleared the fault code and the MIL went out after starting so all was fine for 2 days - then the light came on again a few days later. I checked the code and it shows P0600 - which is a serial communication problem I understand.

Does anyone know what needs to be done to get this intermittent fault corrected?

Many thanks,
Nigel
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g8dhe
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Re: Engine Management Light Stays On - Intermittent

Post by g8dhe » Fri Nov 06, 2020 2:47 pm

This is just a guess as the wiring diagrams don't go up to the date of your vehicle, but do you have a Leisure Battery fitted ? In which case is it remaining fully charged, as normally the ECU backup supply will be coming from the LB and if it goes flat it will flag this up as an error that clears after the next start.
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sickonit
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Re: Engine Management Light Stays On - Intermittent

Post by sickonit » Fri Nov 06, 2020 5:25 pm

Yes there is a leisure battery fitted - it was brand new when they did the conversion to a campervan (as is the main battery) in Dec 2019. I put an intelligent battery charger on both the main battery and LB every few weeks or so to keep them topped up but I will check the LB tomorrow and let you know.
sickonit
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Re: Engine Management Light Stays On - Intermittent

Post by sickonit » Sun Nov 08, 2020 2:34 pm

The LB's voltage is 12.2v whilst the main battery is 12.5v.

As the MIL staying on is intermittent, I suspect that it's not the alarm/immobiliser that is faulty otherwise the light would be on all the time.
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