SkiMiester

Wifes 2004 S430

History:...
-Possible continuation of problem (Limp Home Mode) from May 10/10 which occured at stop at end of off-ramp at end of Highway Trip.
-Made it home, turned Car off, waited a minute and turned car back on and problem went away. Took to Dealer under ELW but no Codes were found, although they did find a bad O2 sensor which they replaced.

Currently:...
-At stop at end of off-ramp during (desert) Highway Trip vehicle warning 'Pre-Safe Disabled' message came on.
-Would not shift out of 2nd (in auto-mode).
-C/S switch would not function.
-If shifter was tilted left or right it would flip through the numbers but would have no effect on shifting.
-Turned Car off, waited a few minutes and turned car back on and problem went away. I am sure this anomily will not throw off any Codes either.

Soooo, what could cause such a debilitating effect on the Drive-Train then suddenly disappear without a trace.

Thoughts please.

gtivw1992

go back to the dealer and ask them to ck the r/s rear speed sensor connector , and ck for codes on etc , when presafe message come on the cluster, there should be a code store on presafe , presafe modules are the seatbelts

SkiMiester

Thanks...

But why won't the tranny shift?

gtivw1992

go to the dealer and ask them to ck for codes , sometimes the r/s speed sensor gets wet not sending reading of wheel speed to esp control unit and then esp send it to etc control unit making it go to limp mode (SAFE MODE) , sometimes when the r/s speed sensor is wet it wont set codes , presafe comes on because the esp stops sending data to the the presafe modules so if there are no codes on etc or other modules , as the dealer said , ask them to ck for codes on presafe , if they cant find fault codes on the other modules, presafe will gave an idea where problem is,

my06clk

Because your problem is with the Valve body which houses the Transmission control module on your model. I just went through the same thing with my 04. Mine began as an intermittent issue but progressively got worse. This is an issue with the 7 sped tranny's.

Mercedes is being hush hush about it, but last Feb, they prohibited any of these units to be sold in the US an had all of the the spaore stock sent back to germany for an upgrade. It took about three weeks before they released the "new" part. but they are supposed to be all good now.

I'm keeping my receipts just in case a delayed recall alarm goes off. I can get reimbursed.

If you dealer is not familiar, tell them to run a diagnostic on your tranny module and you will find that many elements of the test will fail.

Syptoms are Pre-safe message, and you will also notice that you can not use the auto stick when this situatuin occurs. To reset, simply put the car in park, shut it off, and restart and the system will reset and work properly.

The cost of the job is about $2500 so be prepared for that. Othewise I would not delay, I milked my for about 18 months till it finally got worse and I had it repaired.

BTW. the presafe message is circumstancial.. That's what threw us off before n the earlier stages of troubleshooting this problem when it was random.

SkiMiester

You are the man MY06clk....

This is the kind of info that makes this site so valuable.

I will be using this info to direct my service rep in the right direction.

Then after he gets the test failures I will make sure it gets remedied.

2H S5

It's fortunate about this site for having knowledgable members.

However, this service rep/dealer who MISSED this (if this is the problem) is incompetent

It's not like you're the only who has this problem

If if you pointed him in the right direction, you should get a discount on your repair.

SkiMiester

Update:
They pulled codes P200A, P2204, P206C...They tried to access the module and noticed 722.6 on the screen but 722.9 Tranny is installed. EHS number was not found. They were only able to get limited access to Tranny software function...unable to get Adaptations and/or Control Unit log. Attempted to Re-Code and update Software...no luck...Many error messages. Removed pan to see actual part number on the Valve Body...found 10 06. Created TAC case for further diagnosis. Got approval to replace Valve Body Assembly...removed and replaced Valve Body/Control Unit...replaced Trans pan with new style...Performed Software updates to Tranny and to ECU...Re Adapted tranny and everything is good.

Bonus:
Got them to replace the Instrument Cluster since I had a few Flicker occurances documented in the past.

Thanks to all, especially MY06CLK, for the input.