Transmission overhaul caused three problems ('96 E300D) - PeachParts Mercedes-Benz Forum

Jeremy5848 · #1 12-11-2007, 10:20 PM

So, the overhauled tranny (722.438 4-speed) in the W210 car works great but we have found three problems, listed below. The shop will make it good but clearly, everything we can do to help them will make it go faster. Put on your diagnostic caps and figure out what would cause these three things to simultaneously occur as a result of the overhaul job:

1. Reverse lights on all the time -- as soon as the key is turned and whether the engine is running or not and regardless of the gear selected. (I pulled the bulbs to keep from blinding the behinders at night so now we get a dead lamp warning, oh well.)

2. Engine will start in any gear -- PRNDS.

3. Cruise control does not work. (Just for grins I checked the fuses, all good under the hood, haven't checked under the rear seat yet.)

This sounds to me like a neutral safety switch problem, maybe they broke it, forgot to connect something, put it in backwards, etc. Do you agree? Why would the cruise control be affected? Will they have to pull the tranny to make the fix?

Jeremy

PS: The wrench reported that, except for the leaking seals, the wear parts of the transmission were in pretty good shape, especially after 249,000 miles. The reverse clutch (starting to spit a few pieces) was the worst thing he saw. It would have been good for many more miles (to 300,000?) if the leak had gone away. That's pretty good, I think, and confirms that the three previous owners took care of the car and didn't abuse it. An interesting data point -- I didn't think they would last that long.

TMAllison · #2 12-11-2007, 11:43 PM

I think you are on the right track with your thinking about the NSS. Clearly should not start unless in D or N so something is connected incorrectly or is broken.

No comments concerning the cruise control but suspect its speed signal is related to the trans.

Do they have SDS to read trans codes? Might be helpful.

Jeremy5848 · #3 12-11-2007, 11:57 PM

Quote:

Originally Posted by TMAllison

I think you are on the right track with your thinking about the NSS. Clearly should not start unless in D or N so something is connected incorrectly or is broken.

No comments concerning the cruise control but suspect its speed signal is related to the trans.

Do they have SDS to read trans codes? Might be helpful.

Not sure what "SDS" is; transmission is not the newer electronic one so possibly no codes to read. I just tried my code reader on the car -- no codes are set, it says, so the computer doesn't know about this problem, the tranny doesn't talk to it.

I thought the cruise control got its signal from the speedometer but maybe the W210 cars are different.

Jeremy

iwrock · #4 12-12-2007, 01:08 AM

SDS is the Star Diagnostic System.

Scan the car, see if it is getting a signal from the trannie selector. If it isnt, then check that.

Jeremy5848 · #5 12-12-2007, 01:49 AM

Quote:

Originally Posted by W124.090

...Scan the car, see if it is getting a signal from the trannie selector. If it isnt, then check that.

Sorry, don't understand.

Jeremy5848 · #6 12-19-2007, 06:44 PM

OK, so the neutral safety switch was bad. The tranny shop replaced it, car now starts only in Park or Neutral. However, the backup lights now do not work at all (bulbs are good) and neither do the turn signals. The backup lights I knew about when I picked up the car today; the turn signals I found out about on the way home.

The problem with the backup lights is likely due to a short or break in a wiring harness. Mercedes used a new "environmentally friendly" insulation and it falls apart after a few years. This causes bare wires to touch. The transmission mechanic (Brad) found that the wires were touching and patched it as best he could.

The 4-way flashers work, so the wires and the bulbs are OK, just not the turn signals. The combination switch could be partially bad (coincidence). I wiggled it but the turn signals will not work at all. Headlights, taillights, etc., all work. The high-beam switch works. I forgot to check the windshield wipers. Is there any part that is in common with all of this? I don't know how computerized the '96 is -- much more than the W124 cars, I suppose. Sure wish I had a wiring diagram for this car.

Jeremy

Hatterasguy · #7 12-20-2007, 12:40 AM

Justin is talking about MB's super computer that it hooks up to its cars. I'm not sure on yours but on the 722.6 and newer it will tell you just about everything thats going on inside. Even how worn the bands are, amazing stuff.

Parrot of Doom · #8 12-20-2007, 08:02 AM

Check the wiring to the reverse lights isn't broken on the 'trunk' hinge, or below the rear seat. Its the most obvious place for it to die.

As for your indicators, if the turn relay is working then all it can be is the stalk, or the connection to it. You need to dive in there with the multimeter to test for continuity.

Brian Carlton · #9 12-20-2007, 09:12 AM

Quote:

Originally Posted by Jeremy5848

The problem with the backup lights is likely due to a short or break in a wiring harness. Mercedes used a new "environmentally friendly" insulation and it falls apart after a few years. This causes bare wires to touch. The transmission mechanic (Brad) found that the wires were touching and patched it as best he could.

Prior to the most recent trip to the garage, the reverse lights were on 100% of the time.........until you pulled the bulbs.

It would be difficult to make case that the wiring harness failed since the most recent visit and that it is the reason for no operation of the lights. It's far more likely that the switch for reverse is not making contact.

Jeremy5848 · #10 12-20-2007, 05:01 PM

Turns out...there is a third fuse cluster, unknown to me

at the left side of the instrument panel, under a hidden cover. Most of the car's lamps are fused from this panel. Perhaps it was in the owner's manual and I simply missed it. (Sure would like a shop manual for this car!)

At any rate, the #4 fuse in this panel had blown, taking out the backup lights and turn signals. The fuse probably blew when the bare wires in the reverse lamp switch shorted to ground while the transmission mechanic was replacing the neutral safety switch. If the mechanic insulated the wires correctly, the fuse won't blow again...we shall see.

The on again--off again lamp warning problem turned out to be a foglamp with a damaged filament. The filament was touching one support loosely; when the mechanic and I checked all the lamps yesterday it worked. Later, the filament failed to touch the support and the lamp warning circuit was activated. Replacing the bulb made that problem go away.

In the process, my indy had the lights on for twenty minutes or so and ran the battery down. Although the battery (an Interstate MTP-93, new in 2005) tests good as regards "cold cranking amps," it cannot tolerate a load of ten or twenty amps for more than a few minutes without starting to die. Under normal circumstances, I'd attempt to stretch out the life of the old battery for a few more months but seeing as how we leave for snow country tomorrow.... Therefore, I had the indy replace the battery with a new one of the same kind. So something good came out of this fiasco.

The 1996 E300D has the older, non-electronic 722.4 transmission. Fortunately or unfortunately, it cannot talk to the computer.

Jeremy

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode