MERCEDES BENZ ML430 Tranny problems

[AvechuchoAxel]

I'm working in this 1998 vehicle after 2 or 3 other mechanics tried before to repair some issues on the ETC. (Transmission Control)

They replaced:
2 transmissions
Transfer Case (AWD)
ETC Module
ABS Control

The vehicle still having the same issues as it's was since the beginning... (wasted money)

Now I have this car and already diagnosed by me with DAS.

The symptoms are:
After start the vehicle shift normal to 1rst - 2nd - 3rd gear, after that the tranny sets to SAFE MODE. Only one gear is engaged (I guess is 3rd)

After restart the engine, tranny goes back to normal.

Now the DTC's are the following.

ETC
008 R/P Lock actuator Y66/1

051 Gear implausible or transmission slipping

097

104 Sporadically R/P lock actuator

147 Sporadically gear implausible transmission slipping

After run some tests and actuation's, I saw that the tranny oil temp is set to -99 degrees, which means there is a fault or this tranny doesn't have temp sensor.

Also ME 2.0 (ECM) reports the dtc P0700 (Read ETC fault code memory)

ESP shows C1140 (Steering Angle Sensor N49 not initialized). I did the ZERO POINT reset after that.

After erasing all the codes and start a fresh test road only remain the ETC codes 008 - 104 - 147.

--------------------------------

Some of the test performed.
Modulating Pressure Control Valve
ON 495 / 505

Shift Pressure Control Valve
ON 495 / 504

SHIFT VALVES
No fault Codes

Transmission oil Temp
-99 Celsius degrees



Any of you guys has a direction to follow? Thanks!!!

[GolfmkI]

Shift valves? Ecu defective? Bad connection in round connector of gearbox? Internal problem in the "pcb" where shift valves are mounted?

I had a similar problem in a E-Klasse and must say it is very difficult to check, next time I will think about repairing this failures. Have luck.

[AvechuchoAxel]

Shift valves? Ecu defective? Bad connection in round connector of gearbox? Internal problem in the "pcb" where shift valves are mounted?

I had a similar problem in a E-Klasse and must say it is very difficult to check, next time I will think about repairing this failures. Have luck.

I have had a lot of help from other forum mates... The point of the direction to follow is to check valve body version and ETC version. Those, along with the transfer case module where replaced just matching the part number. I bet my A$$ that they never ever ever CODED the modules or performed any kind of clearing and new values learn adaptations.

The transmission oil temperature may or may not be causing troubles because an defective harness or defective sensor inside the transmission.. Also the round connector inside the tranny must be verified.

Looks like I have a lot of painful FUN for the next days coming.

Regards Axel

[Albanais]

Hi mate
maybe what i will tell you might be stupid but you have to try. Did you you check your earth points and earth cable. Even if you are sure you have checked them dismount them and make a visual check one by one, they may be corroded and this gives to you insignificant fault codes and problems which looks to you strange

[roth18]

Two trannys replaced, did you check if possibly the trans cooler is plugged up with junk from the other transes. If you have metal shavings in the cooler they will mess up the valve body in new tranny.

Roth.

[AvechuchoAxel]

Both are a valid recommendations to look at over. I didn't replace the tranny's, so not sure if the tech who did it check all those points.
I have to start all over and also check for possible differential replacement and/or wrong gear ratios.

But before start doing all this $hit, I will call the customer to get him aware about the amount involved on this repair. If SHE goes cheap..... I will throw the ball same Monday.

Thanks to all!

[Dajan2009]

I recommend to check the flow through the oil cooler, presence of metal shavings in the oil pan, earth connections, wires betwen tranny and ECU, and the converter for big metal pieces falling out.

[autotrans]

CODES 008 / 104 are quite often associated with electronic
selector even though there are no selector codes present
C1140 is a persistent little bugger just ignore it .
check temp thermistor from ecu plug pin 33 to 34 approx 1k
cold ( selector must be in D position ) . pin 33 sensor ground
is common to thermistor and both speed sensors . have you read live data on speed sensors.
interface problems are very common , we have even seen ATF get past the round plug up ( yes up ) the cable to ecu

[AvechuchoAxel]

UPDATE:

I did several test on this vehicle.... The shifter was replaced and the dtc codes for shifting never came back.
I have only those codes related with the possible transmission slipping and implausible gear ratio (051 / 147)

This is the screen images of DAS during test.

ML430 DIAG pictures by AvechuchoAxel - Photobucket

Normal UPshifting from 1st to 5th gear... vehicle act normal for a 30 miles test at freeway speed (60mph).
DOWNshifting from 4th to 3rd is when transmission goes to LIMP MODE.


Thanks

[Ne0]

UPDATE:

I did several test on this vehicle.... The shifter was replaced and the dtc codes for shifting never came back.
I have only those codes related with the possible transmission slipping and implausible gear ratio (051 / 147)

This is the screen images of DAS during test.

ML430 DIAG pictures by AvechuchoAxel - Photobucket

Normal UPshifting from 1st to 5th gear... vehicle act normal for a 30 miles test at freeway speed (60mph).
DOWNshifting from 4th to 3rd is when transmission goes to LIMP MODE.


Thanks

I think problem in torque converter - as I understand, you not replaced TC, or/and Y3/6y6 - torque converter lockup PWM solenoid valve, Y3/6Y4 - 3-4 shift solenoid valve (mounted on EHS).

And about EHS , Y3/6 plate , solenoid valve's - you replace it, or use from old transmission ?

Regards,
Ne0

[autotrans]

Sounds like lock/up problem, possibly dropping out to early on downshift . with Mercedes scanner you can disable lock/up ( just to prove the point )