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Old April 20th, 2013, 17:51   #9
Veteran Member
Join Date: Aug 2007
Location: Chapin, South Carolina, USA

After the engine cools, log a start attempt, please.

The following values are for interpreting MVB005 field 3. They are actually for a BEW PD, but a good working assumption is that they are the same for your BHW.

Basic initialization
Counter reset
Engine switched off or malfunction
Transitional states
Plausibility check phase
Plausibility check phase
Plausibility check phase
Plausibility check phase
Phase verification
Synchronization phase
System positioning
Calculation sequences activated
System waiting for engine stop
Dynamic plausibility check

I think that your engine is possibly seeing a difference in the crank and cam sensor, or is getting a bad signal from the crank sensor when hot.

A BEW cannot run without a crank sensor (on only the cam sensor), A BRM can. The BEW and the BRM can both run without the cam sensor. I have no idea about your BHW.

Note your MVB 004 field 4 value when hot running, just before shutdown, does it go to 0.0? If it does, that may indicate that the ECU is substituting a value in for the cam-crank difference - it does this when the sensors are not agreeing.

Try unplugging the cam sensor when trying the hot start. Log MVB 005.

Plug in the cam sensor, unplug the crank sensor when trying the hot start. Log MVB 005.

When the engine is cold do the same things, capturing the logs.

If you alter the name of the file (put hot no cam after the number but before the .csv) before you start logging it, then you can keep your data straight by using the different files.

I have seen several hot failures of the crank sensors, and they throw no codes. Not sure why. But I have added crank sensor failure to my list of "no code no start" potential problem list.
DanG144 is offline   Reply With Quote
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