Lost Communication with TCM

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ancuislean

New Member
Joined
Nov 5, 2010
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7
Hi, Looking for advice, I have a 2007 E220 CDI, it was caught up in some minor flooding and water got into the footwells. The car is going very well aspart from the orange engine management light being on permanently. I got it switched off at the weekend. The error message on the diagnostics was ' Lost Communication with TCM '. The light stayed off for about 10 miles before coming back on. As I said the car has full power with no apparent problem. The passenger side modules mounted to the tin plate were replaced, I was given the original modules, I checked the 'new' replacement modules and discovered that they were salvaged from another car and had different numbers, The original module is a Siemens VDO EGS53, 5WP20124AK, Merc Ref A0015453116. with TCM. I suspect the replacement may be the reason for the light staying on. My questions are ( 1 ) is this passenger side footwell module the TCM. ( 2 ) Does replacing this module require star type diagnostics to tell the car it is replaced. ( 3 ) are these simply plug and play or do they need exact matching. ( 4 ) Is this likely to be the problem or would you be looking somewhere else. ( 5 ) Am i correct in saying that this unit is not the ECU. Any help / guidance would be appreciated. Thanks,
 
Hi

EGS53 is the EGS (gearbox controller), and assuming that message means its losing contact with the transmission control module, then that is it.

They do need coding for the vehicle (they get SCN coded when installed) with Star Diagnosis as its the same module for most engines that just behaves appropriately. The module part numbers change from time to time as new revisions are made, so it is likely more than 1 part number will work find in your car. If you PM me your VIN (chassis number) and the part number of the module that is now in the car i'll tell you what the parts catalogue says.

It is an ECU (i.e it has a computer in it and controls things).

I guess (only a guess) the message could be because its wrongly coded, but i'd (a) get it coded correctly and (b) check all the contacts in the car's wiring loom that had any chance of getting wet for corrosion.

Also, if the boot got corroded, you need to watch all the electronics on the left hand side carefully - as they go wrong if water gets jetwashed through the vent behind the side of the bumper and things like the navigation drive are expensive.

Cheers

Richard
 
Also, in the passenger footwell wiring duct are a load of connectors that you should check - I think the CAN bus multiway connector which connects things in the engine is there, and corrosion there could cause your important safety stuff to go badly wrong ..
There may be extensions of that also in the driver's footwell wiring duct, so check that out for connector corrosion too.

The CANbus distributor is about 10cm long x 1cm x 1cm and the engine one has lots of pairs of green,green/white cables going into it.
There is a interior CANbus distributor - very similar but has brown,brown/red wires and that is fixed to the bottom of the glovebox so should have stayed dry.

Richard
 
Hi Richard,

Thanks for your help. When I got the car I discovered the carpets were not fully dry, the sealed sponge underlining still contained a residue of moisture. I completely removed the interior to dry it out, seats and carpets front and rear, the centre console, etc. I removed the tin pan on the passenger footwell containing the 2 modules, the Siemens VDO EGS53 and also a Temic 2115458432 ( think this is the front SAM module ). I sprayed all the electrical contacts with a electrical contact cleaner. The is no evidence of corrision when the car was stripped back, some 9 months since it was caught in floods. The Vehicle VIN number is WDB2110082B222655. I will remove the front passenger carpets to remove the tin panel and check the numbers on the replacement modules at the weekend. I suspect that ithe Star Diagnostic coding may be worthwhile, but then why would it travel for 1/2 hr with no light showing. Thanks for your help.

Regards

Frank
 
Hi Richard
Reoved the panel today to expose the TCM, the label on the replaced one is quite badly smudged but i can make out that it is EGS51 the last few digits on the numbers below this is 00W20, not sure if thats any help with checking suitability. Thanks,

Frank
 
Mercedes Code Errors

Hi,

E220 CDI 2007 model with engine management light staying on. I plugged in the Sealey Diagnostic tool and got 2 errors, on the CDI tab I got the error P22DD, On the ESP tab I got the error C1486, on both the AB and CGW tabs no errors. I switched off both errors and drove the car, engine management light went off at car startup. It stayed like that but came back on this evening, plugged in the tool again and got the 2 same errors, switched them off and then tested the car again, light turned off at startup and then i switched off the engine and retested with the tool, no errors appear, all that shows up in the menu is AB and CGW, both of which pass the test and read as having no errors. This is the third time I have switched off these errors and based on previous experience I reckon they will appear again. Any advice on what the errors are and how to recticy them would be greatly appreciated. My previous ' lost communication with TCM ' is no longer appearing as an error. Thanks.

Frank
 

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