Limp mode again

[500ESpain]

Hi,

After replacing the ETA, MAF, brake light switch and upper wiring harness I thought the limp mode problem was solved but here it is again. I'm quite dissapointed because I'm afraid of using the car (doesn´t feel very good going into limp mode when overtaking other cars). What should I test next? ASR module, ABS sensors?

Thanks

 

[195910]

First have it checked with star diagnosis, and please post the fault codes here together with a list of everything you changed.

When does the car go into limp mode? what happens before that ?

I hope we can help.

 

[gsxr]

Yes, we need the codes - all of them from all modules - to assist further. Sorry you're having this trouble!

Just curious, has the gear position switch / starter lockout switch been changed, the one on the transmission?

 

[195910]

Just curious, has the gear position switch / starter lockout switch been changed, the one on the transmission?

Speaking of that switch, I diagnosed a friend's 500E, and it had a faulty gear position switch. The ideal was pretty bad, it felt like the car was engaging into D and coming out all the time (high-low-high ideal). Turned out that the switch gave signals that the transmission is in 2 or 3 gear while the it was actually in P. I was lucky to notice that.

 

[500ESpain]

Thanks for your quick answers. I haven't had the time yet to take the car to my mechanic but as soon as I get the codes I will post them.

The car goes into limp mode with no previous advise. You're driving and suddenly it happens. For example, the other day I made a 120km (75miles) trip at an average speed of 90mph. It drove perfectly for about 70km until it suddenly went to limp mode constantly for the next 30km (I had to restart it all the times). Then, perfect again for the rest of the trip but the car lost some power (I think, maybe I was just paranoic). On the return trip it run perfect at 90mph. This time the air conditioning wasn't on but I don´t know if this could be related to the problem (voltage maybe?). So far, the problem only happens cruising on the highway.

I haven't changed or checked the gear position switch / starter lockout switch. I have new ETA, MAF, upper wiring harness and brake light switch. Let's see what the codes say.

Thanks again!

 

[500ESpain]

And one more question... is the gear position switch / starter lockout switch the same as the Neutral Safety Switch? I understand one of the things this device does is telling the computers which gear is selected. Is that right? Could it be the reason why the idle is bad when the car is in N or P but runs well on D?

 

[gsxr]

And one more question... is the gear position switch / starter lockout switch the same as the Neutral Safety Switch?

Yes. The switch performs all of the above functions.

I understand one of the things this device does is telling the computers which gear is selected. Is that right?

Yes, that is correct.

Could it be the reason why the idle is bad when the car is in N or P but runs well on D?

It's possible, but somewhat unlikely. If the switch is original, it's likely due for replacement.

 

[195910]

Thanks for your quick answers. I haven't had the time yet to take the car to my mechanic but as soon as I get the codes I will post them.

One note here, if its the gear position switch, it might not show as a fault code! the car I tested did not have a code for this, but the I saw the fault when reading the live data.

 

[500ESpain]

Thanks for your help, guys!

 

[500ESpain]

Hi again,

I finally got myself a code reader and this is what I got

Pin 6 ASR

5 Left rear axle VSS sensor, open circuit (speed sensor on the wheel?)

30 ASR only: CAN data bus to EA/CC/ISC control module interrupted (maybe when the ETA was replaced and the code wasn't deleted??)

Pin 7 EA/CC/ISC

2 EA/CC/ISC Contorl module (N4/1) or
Safety contact switch (M16/1s1) or
Stop Lamp Switch or (the car failed again after raplacing this)
Cruise Control Switch or
Actual Value Potentiometer or
Starter Lock-out/back up lamp switch or (NSS??)
Engine speed signal or
Vehice speed signal or
Closed throttle position switch or
Safety relay in EA/CC/ISC control module

7 CAN data bus signal from EA/CC/ISC, ABS/ASR,HFM-SFI or LH-SFI (right or left) control module faulty

Pin 8 Base Module

5 Maximum allowable temperature in module box exceeded

I'm not sure how to interpret that data. Your help will be appreciated.

Thanks!

 

[500ESpain]

And I forgot: Closed throttle position contact switch at Pin 7

 

[gsxr]

Excellent! Now you need to clear all the codes, then check frequently afterwards and see which ones return. The codes which return quickly are the ones to focus on. (I hope these all don't come back right away.)

The BM code is pretty common and doesn't mean anything - you can ignore that. E-Gas code 2 shows why a digital scanner is helpful, as it will pinpoint (more closely, anway) which of those items are at fault, via 3-digit codes instead of the single 2-blink code. See screen shot below. ASR code 30 is another generic one that pops up when other things go wrong, but ASR code 5 could be a bad sensor (or wire) if it returns immediately. If it doesn't come back, it was probably a fluke.

 

[500ESpain]

Thanks, Dave. Very useful but now I want/need a digital scanner . I think the problem is the speed sensor because if I remember well the ABS light went on too the last time the car went into limp mode.

And one more question. Is the "Closed throttle position contact switch" the same as "idle speed contact switch" that Gerry expained how to replace. Maybe that coud be the reason for the occasional misfire I have.

Thanks again. I don't know what I would do without your help

 

[Benzer]

Hi,

Can someone recommend a simple procedure to put the safety clip that goes on the shift rod back in place. I need to replace the rubber insert, (p/n 1159920310) on the range selector rod where it meets the NSS selector and don't want to have 2 Hr. battle under there again...

 

[gerryvz]

There are a couple of tools that assist in the replacement of the hard plastic insert into the shift rod. I have found, with practice, that I can do it with manual methods (pliers and a large flat-blade screwdriver, pretty fast (30 mins). It also helps if you can remove the shift rod, but this is not always possible to remove the part from the car (or, at least easy to do).

As for the safety clip, I use my fingers, needle-nose pliers and a flat-blade screwdriver to hold the clip, then the screwdriver to spread it a bit to slide it into the slot on the end of the rod.

Come to think of it ... I need to do this on my 560SL....sheesh, another weekend project.

Cheers,
Gerry

 

[gsxr]

The end at the transmission is simple. The end at the shifter is awful to access. If you are ordering parts, I'd buy a spare metal clip, as it can go flying and you may not be able to find it afterwards. Good idea to keep a spare around just in case...

 

[Christian_K]

OMG i have to do this aswell when i insert the engine/gearbox into my car.
As i was looking under the car, i noticed that the plastic insert is gone down at the end of the shift-rods thingy. It was already a pain-in-the ass for me to replace that at the gearbox, now readying that... jesus im scared.

 

[gerryvz]

You just have to suck it up and do it. Not fun, but there are FAR worse jobs out there. Give yourself plenty of room under the car, that makes it a bit nicer when you're comfy. Also, some people say to boil the rubber bushings in a cup of water in the microwave oven (or on the stove top) for a few minutes before you replace them -- the softness is supposed to help get them through the holes in the levers.

Here's a write-up on the process, along with a sort of home-made tool. This is from a 560SEC but same principle as our cars -- though clearance in the tunnel with the E500E is a bit tighter than with the SEC.

http://home.comcast.net/~chwilka/replac ... ushing.htm

LOL ... just stopped at my stealer a little while ago on the way home from work and grabbed a few new bushings and a couple of end clips. Gotta do my 560SL this weekend.

Cheers,
Gerry

 

[Christian_K]

You just have to suck it up and do it. Not fun, but there are FAR worse jobs out there. Give yourself plenty of room under the car, that makes it a bit nicer when you're comfy. Also, some people say to boil the rubber bushings in a cup of water in the microwave oven (or on the stove top) for a few minutes before you replace them -- the softness is supposed to help get them through the holes in the levers.

Here's a write-up on the process, along with a sort of home-made tool. This is from a 560SEC but same principle as our cars -- though clearance in the tunnel with the E500E is a bit tighter than with the SEC.

http://home.comcast.net/~chwilka/replac ... ushing.htm

LOL ... just stopped at my stealer a little while ago on the way home from work and grabbed a few new bushings and a couple of end clips. Gotta do my 560SL this weekend.

Cheers,
Gerry

Merci a 1000 times, that self-made too is genius. Why haven't i come up with some sort of idea like this, damn..... if i remember back how often that thing did pop-out again after it was almost in its place.... i cursed so many times... ^^

 

[gerryvz]

With regard to bushings:

viewtopic.php?f=20&t=1288&p=7547#p7547

Cheers,
Gerry

 

[Benzer]

The end at the transmission is simple. The end at the shifter is awful to access. If you are ordering parts, I'd buy a spare metal clip, as it can go flying and you may not be able to find it afterwards. Good idea to keep a spare around just in case...

Yes I did buy a spare one to use while I replace the bushing on the control arm on the NSS. Finding that damn clip turned a 30 min. job into an ordeal... Still haven't gone under there yet, I guess I will do it one of these days when I wake up with a lot of patience.. Getting it done the first time involved a LOT of cussing..