1992 500E pulled codes

[e300d]

Hello folks,

1992 MB 500E 140K miles

Original harness and ETA. Just working on the car, trying to work out the bugs.

Car start fine. Runs fine then ASR light comes on.

Idles fine for 15 min, then as engine temp goes up I hear it misfire.

I then shut it off and unable to restart until engine cold again.

Made a blink code reader..got the following codes:

Pin 4 - Unable to communicate, tried few times. No blinks coming out at all. (Dont know what I am doing wrong..)

Pin 6 - code 31 - cleared it

Pin 7 - code 3 6 14 - cleared all

Pin 8 - code 6 9 10 11 12 - cleared all except code 9 stays

Pin 17 - 38 - cleared it

So looks like PIN 8 code 9 stays on. (Engine 104, 119: LH-SFI control module (N3/1) voltage supply, open circuit.)



NOt sure why I am unable to pull codes from pin 4.

Thinking what I should do next. Pull the ETA and have it test/rebuild or perform more diagnosis.


Thanks for your help.
Sebastian

 

[gsxr]

Check the fuses on the BM, although I don't think the car will run if the LH fuse is blown...? Never tried though. Make sure you are using the correct pins. Strange...

 

[DerFuror]

:slotje:Make sure the module is fully seated in position!

Also, an original wiring harness will always be a highly suspect conduit to electrical & engine mgmt problems. Verify its manufacture date & consider replacing if it actually is original.

Supporting threads exist on the topics.


...Oh, and disconnect & firmly reconnect your battery cables after making sure the terminals are spotlessly clean.

 

[e300d]

Hi Guys,
Its been a while since I worked on the 500E. I finally moved it to my house and now its just residing in my single car garage. Taking up space lol..

Anyways I have kept a trickle charger on the battery for a few days. Anyway the car does not want to start anymore. It has a healthy crank, oil gauge pressure comes up to 3 bar.

So car cranks but no light off.

I opened up the Can Bus to see the computers. I went to look at the BM. I noted only 3 Fuses in location F1 F2 and F3. nothing in F4 since I guess that is for W140 and other chassis.

The fuses look good, I took them in and out all OK.

I then rescanned the car again.

PIN 4 : I plug in all wires and hit the momentary switch on my code reader and all I get is a single blink as I press down the momentary switch, but that it. Seem like there is an issue with that.

PIN 6 : Code 31 - CAN data bus to LH-SFI control module (N3/1), Left LH-SFI control module 23 28.0(N3/2), Right LH-SFI control module (N3/3), or Engine control module (N 3/4), Read out DTC for N3/1, N3/2, N3/3, N3/4: see
interrupted

***Hmm seems like a voltage issue?

PIN 8 :Code 9 - Engine 104, 119: LH-SFI control module (N3/1) voltage supply, open circuit.



PIN 17: Code 27 - LH-SFI control module (N3/1) data exchange malfunction


In summary. Car still sitting in garage, not driven. It started and run ok for 5 -10 min then started to stumble run rough and die.

Now it cranks good but does not start at all.

So I am thinking the battery may be getting bad and does not provide good voltage.. OR the wiring harness is just shit and I am getting all these weirdo codes..

Wiring harness: OLD original from 1992

ETA : OLD, original.


So after reading all the threads here and such, it seems like I should first start on the wiring harness and ETA since they are both old and have not been replaced.


I also bought a set of all new ceramic fuses that I will replace all the fuses in the fuse box.

Any advice would be appreciated ,

Regards
Sebastian

 

[gsxr]

The engine wiring harness is definitely suspect, but I'd double-check the battery terminals first. Note the positive terminal has two separate nuts (one 13mm, one 10mm) and both need to be clean & tight.

Bad ETA should not prevent the car from starting, so worry about that after it's running again.

Everything is pointing to the LH module not receiving voltage. I would try to fix that first, so the code on pin 8 (BM) does not come back:

• Make sure ALL modules in CAN box are fully seated - whack them hard with your fist
• Triple check the battery terminals, especially the smaller wire at the positive terminal
• Try a different BM (same on all 400E, 500E, and maybe some 140/129 too)
• Try a different LH module (for test purposes, any 5.0L LH module is ok)

In the meantime I'd start looking for a good engine harness. I think there are a couple used ones for sale at the moment for a lot less than

 

[gsxr]

Update: It looks like pin 8 code 9 is complaining about an unfused voltage supply. After triple checking the battery terminal connections, the next likely fault is a bad Basic Module... assuming all modules are fully seated. The fuses in the BM should not be the issue here.

 

[olec]

Not sure if we have the same problem, on my1994 i did some preventive maintance like replaced the 4 pin coolant sensor, after that car woud run up to 80 celsius and just quit, after it cooled down it would start up, started to check the wires for the 4 pin sensor and found they where cracked inside, I insulated each wire and tryed again and it ran fine in idle for an hour.
What I have now is a lot of respect for the upper wire harness especialy if it is the original. Just got a new harness from the Classic center and put it in and everything is fine. When i got the old harness out almost all the wires was very poor, could not see it before I started to pull in the wires, don`t trust those upper harnesses unless it is new!

 

[e300d]

Did some work on the car today:

Swapped out the battery to see if it was faulty

Cleaned/ tightened the battery terminals

Swapped out all the fuses in the fuse box next to brake reservoir with new ceramic ones.

Removed the BM and cleaned the contacts.. Put all back together, made sure all is tight

Still cranks no start at all.

Go to pull codes

Still Pin 8 code blinks 9

I think someone has already messed with the Basic Module..part number shows one from a 400E...

I took out BM again, opened her up.. looked over the circuitry. All looks good visually.

Here is a pic of the BM..

I think I should just stop messing with Codes and just rip out the goddamn original upper wiring harness..

 

[gsxr]

009-545-91-32 is a valid BM/GM (Basic / General Module). It was superceded by the newer 011-545-97-32, but either part number is fine.

I don't think the upper engine harness is the cause of the problem. But since it's original from '92, it wouldn't hurt to replace it... just don't be surprised if that doesn't cure the problem.

Question: You are clearing code 9 from pin 8, correct? So you see one blink on the BM after clearing? Then after you try to start the car, code 9 comes back?

 

[e300d]

Hello Dave,


Thank you for the reply. After I re-checked everything. I am still having trouble communicating with PIN 4 in on the 38 connector. When I plug in my tester and depress the momentary switch, the LED blinks at that instant and that is it. The LED should stay lit when I press the momentary switch. Then when released it should either blink once = no codes or blink multiple times for various codes...

So seems like I am still having trouble communicating with pin 4

Pin 1 GND and pin 3 Voltage and the 3rd lead to pin 4 LH fuel injection..

Small update:

Went to work on car:

I cleaned the ground locations on the pass side strut mount (2 13mm bolts) . Removed the LH computer and re secured.

Went to scan codes again:

Pin 4 - all I get is a single blink when I press the momentary switch on my code reader. No other blink codes after. All I get is as single blink only when I press the switch on code reader

Pin 6 - Code 31 and cleared.

Pin 8 - getting code 9 cannot erase it....

Pin 17 - code 27 and I cleared it again.

So I am not sure what to do next..

 

[gsxr]

Correct, the code 9 on pin 8 is an error for power supply (voltage) for the LH module (pin 4). So it makes sense that you are getting the error on pin 8. Another possibility is a failed LH module (pin 4) but I'm really not sure.

It would be nice if you could find another vehicle with LH injection to borrow a BM/GM and LH module from for testing purposes. That would tell you inside 10 minutes if either module is bad. Even a W140 or R129 with LH injection would suffice for a quick test...

 

[e300d]

Im a at a bit of a loss as well, parked the damn car in garage, it would always start...now does not want to start. How likely would it be that the LH and BM modules went bad?

I am ready to sell this car....

 

[gsxr]

How likely would it be that the LH and BM modules went bad?

It isn't likely... but it's possible. Are there any other MB owners in your area with 1992-1995 M119 cars? How about a decent indy mechanic? The dealer might not be much help.

:|

 

[gsxr]

From the 500E Intro manual:

"The voltage supply for the [fuel injection] control unit LH [pin 4] ... is by means of Basic Module / overvoltage protection N16/1. ... The voltage supply terminal 15 is protected by [the BM / GM] fuse F2. The voltage supply terminal 30 is directed without protection [unfused] to the control unit LH by the Basic Module / overvoltage protection."​

I'd suspect it's more likely the BM/GM is bad, but it's a tough call. A used BM/GM is cheap since they rarely fail. There are several under $75 delivered on feeBay (click here). The LH module is quite a bit more expensive, depending on which part number you're trying to replace.

 

[e300d]

Havent touched the car in day..

I am having hard time thinking the LH and or GM modules are fried....How do I check if there is voltage being delivered to the box?

Are the grounds for the modules those 2 13mm bolts on the right strut mount?

I do have a decent indy mechanic and his brother in law who I know for some time works at MB dealer..He know the older benzes well. He is just a busy guy with his family and such...

I do not have any friends with 8 cyl Benz where I could swap over the modules..

But having said that there could be a power shortage, the pin 4. the LED only flashes once as I press the switch, the LED does not stay lit up as it should when I press the SPST switch...

Now just to clarify I made my blink code reader with a N/O SPST switch..so I close the circuit in the code reader when I press it. Otherwise its open....



Thanks again...

 

[e300d]

Hi, folks..and Dave lol

I had some time to work on car again. Also I built a new code reader, bought a nice box for it..

Anyways took a multimeter to the CAN bus box...I was able to confirm:

GM/ BM module Fuses F1 F2 F3 are all reading 12.10 V all across

Then I tested voltage at the 38 diagnostic connection

Pin 3 1.62V
Pin 4 2.12V
Pin 6 12.06V
Pin 7 10.74V
Pin 8 11.04V
Pin 17 4.3V
Pin 19 1.53V

This does not sound right....

So as GSXR was suggesting above would the GM/BM be a first hand culprit....looking now at EBAY for some used Basic Modules..

 

[e300d]

wonder if this is one is any good
http://www.ebay.com/itm/1992-Merced...Parts_Accessories&hash=item4170362fd7&vxp=mtr

 

[gerryvz]

Yes the 400E Base Module should work just fine in an 036.

 

[e300d]

Sounds good Gerry,

So for the fact that I am only getting 1.62V at PIN 3 (should be +12V) It is appropriate to get a new/used GM module to see if that cures it...

I already checked all grounds ...

It is too bad I do not have anyone around Toronto that I know with a spare GM that I could just pop in for test purpose..

Ok i bought a used GM from a 92 400E...should get in a week...

 

[e300d]

Hey guys,

Finally got the used BM in to my 500E

Car starts! Thanks especially to GSXR for pointing me to the right direction. The car starts now and idles. Fine

And the ASR light is gone too, well for now.

I am in the road again, I will drive the car a bit around the block when I get home to see how she runs

Thanks again

Will update once I work on car a bit more.

 

[gsxr]

Congrats! Glad it was a (relatively) easy fix. This might be the first i've heard of a BM/GM spontaneously failing - pretty weird.

 

[Glen]

That's great news...congrats!
It would be interesting to try your old module again at some point to determine if it was just a bad connection.

 

[e300d]

That's great news...congrats!
It would be interesting to try your old module again at some point to determine if it was just a bad connection.

Well I re- seated the old one a few times and nothing. I put in the new one and it fired right up.

I am going to blame the voltage spikes from the weak battery and car sitting for a while.

Well now I have more codes:

After clearing all codes. I run the car again. After approx 4 minutes of idling she went into limp mode and ASR light went on the dash

I pulled codes:

Pin 6 : code 21 - ABS/ASR hydraulic pressure unit. Pressure switch A7/3si charge.

and

Pin 30 - codeS 2 3 4 5 6 8 - I hope they are associated with the other codes.
s

**I was surprised no codes on ETA and other pins.

- I do not know the ASR system very well, I know there is a pump located in engine bay. I am now looking for material on the system.

I must say that my brake pedal is squishy and rear brakes are shot. I will need new rear caliper for sure as it seems to be frozen. I wonder if that has to do with the ASR light.

I am going to fix the brakes first. Get a firm brake pedal. It might even be a bad Master Cylinder.

Any other suggestions?

PS. I took it for a quick boot around the block with no limp mode for the first 4 min before ASR light came on and the car definitely has some balls.

Regards
Sebastian

 

[Trae]

"Pin 6 : code 21 - ABS/ASR hydraulic pressure unit. Pressure switch A7/3si charge."

I have lived with this code for years.
I'll start the car, drive a few miles, and then the ASR light illuminates and throws this code.
Don't know what to do about it.

 

[Christian_K]

....
When associated with

Pin #30 - Airbag / SRS (Suppl

emental Restraint System) it, sometimes, points to the ETA.

Never heard of that, and i cant imagine what the SRS System has to do with the ETA???

"Pin 6 : code 21 - ABS/ASR hydraulic pressure unit. Pressure switch A7/3si charge."

I have lived with this code for years.
I'll start the car, drive a few miles, and then the ASR light illuminates and throws this code.
Don't know what to do about it.

Replace ABS/ASR Block or try to flush it with fresh brake fluid first (a guide by someone How-To would be great).

 

[Trae]

I will delete that last portion.
I thought I read something on this site about both the SRS/ASR lights illuminated pointing to a problem with the ETA??????

 

[gsxr]

ASR issues can be related to ETA, as the ETA is part of the ASR system.

SRS (Supplemental Restraint System, aka airbag system) is completely isolated and unrelated to ABS, ASR, or ETA systems.

 

[e300d]

Hi folks,

Just did some work on the 500E...finally got some time today to work on her.

So looks like I have a brake fluid leak somewhere in the system near the driver side front wheel. I thought bad MC because I did not see any fluid drips on the floor and the brake pedal wasnt firm. It keeps on going down to the floor.



Until today. I took off rear break caliper and checked it out. Looks fine. Then I went to pump the brake pedal and wham bid of a drip....

So I am thinking this ASR light might be due to brake fluid starvation in the system.

Next I will track down the fluid leak and flush the brake lines.

In regards to the SRS system with all the codes off PIN 30. It looks like the cars airbag were changed at some point. I know the driver side door was hit but anyways, I need to go back and re-clear all codes again on that port.

Thanks again folks

Sebastian,.

 

[gsxr]

The ASR pressure accumulator is located in the left front fender / wheelwell area. You need to remove the plastic fender liner, then you can see the widgets. Sounds like something in there is leaking - not good.

 

[e300d]

Oh oh I will check it out soon, gone for work...probably next weekend,

Thats weird, could it be rust penetration or a leaky line? Funny I spotted a small puddle after I pumped the brakes while car was off.

Maybe its just one of the brake lines...

 

[gsxr]

Yep - if you live in an area where rust is a problem, one of the lines could have corroded. You will probably find out when you remove the fender liner. Snap some photos & post here if you can...

 

[e300d]

I will be working again on the car, hopefully on weekend. I will def take some pictures.

As a side note. I am also trying to get my parents newly acquired used E320 CDI road ready. Looks like HP might be the culprit there...

I keep you posted. Thanks for all great help.

 

[e300d]

Hey guys.

Been working on car on and off. I have found a corroded line to asr hydraulic accumulator. I have replaced the brake lines ad well as the accumulator. I did take pics with my phone but did software update on it and it lost all my pics!

Anyways recently after getting new rad and clutch fan I was running the car again and got ASR light on again and limp mode!

pulled codes;
Pin 6 code 21 and 30
Pin 7 code 6 and 14
Pin 17 code 38
Pin 19 code 4

Note: I grabbed throttle linkage to rev up engine when asr light came on. Felt it right away as limp mode came on.

Need to find the spec on throttle cable tension.

I'm speechless for now....fight continues.

 

[gsxr]

You can't rev the engine by the throttle linkage, it automatically goes to limp mode and stores codes. You can only rev from the accelerator pedal inside the car.

Time to clear codes & check which ones come back. A few seem related to the throttle cable induced LHM.

Pin 17 code 38 (misfire cyl 6) is weird... maybe check that spark plug, and the resistance of that plug boot.

If you never replaced the ETA or upper harness... might be time to get it over with. The upper harness price is at a near-record low right now, get it while you can.

 

[e300d]

Wow, brilliant! I would have never thought of that! Learn something everyday. Thanks again Dave!

I will clear codes and rescan again.

The misfire is probably weak cap and rotor which I need to replace. I would have already done it but a new rad killed that plan.

Little work I have done :

Used a pressure bleeder to flush brake system, pedal is nice and firm now.

Cleaned front brake components and replaced front brake pads. Rotors are still ok for now with a few mm over the min rotor thickness.

I want to work on the SLS system next. Car is not sagging. However I would like to get a new filter and new hyd fluid.

Also noticed. Rear right tire has excessive wear on inside of the tire. Will have to go over all bushings in rear to see if one may be loose.

Note, the rear of the car is stiff and bouncy. From what I can see bouncy rear would lead to expired rear spheres.

Its pretty cold now here below 0F and I am on the road for next few days. Looking forward to working on it again and taking some pics.

I definitely want to replace the upper harness and also restore the ETA. No question about that. We had 95 E300D few years back and I replaced the upper harness on that.

Cheers
Sebastian

 

[gsxr]

Rear tire wear - check the support joint at the outer end of the control arm. This is often overlooked. There are threads on the R&R process on this forum. Special tool required. Fairly easy job though.

Stiff/bouncy rear suspension = failed spheres. Replace with OE, or Coreteco aftermarket, no other brands. There's a thread or two on this also - make SURE to de-pressurize the system via the bleeder valve atop the SLS valve, or you'll spray foamy fluid all over yourself when you crack the first line.

Get a new upper harness since the prices have dropped so much. Look for a good, used, late-datecode ETA... new ETA's have gotten silly expensive.

 

[olec]

Very very likely upper wire harness, had a similar thing happen to my 1994 E500, I tried to cut the harness open on the 4 prone temp sensor on the front, all 4 wires was caput, tried to insulate them and the car ran fine.
I put a new wire harness on from Mercedes and no more problems. The old harness was really bad.

 

[e300d]

Hi guys

Thanks for the tips, I will check the support joint to see if there is wear. I did some snooping under the rear end last night. Looks okay. The hydraulic lines going to the SLS valve are a bit rusty but no leaks.

I think the spheres are def worn out. Will address than in little bit.

So far I am happy that I dropped in a new rad, new belt tensioner and new belt. I will however need to get new cap and rotors.

When car is cold, idle is fine. Once she gets up to temp, there is a slight misfire, I am pretty sure it is cap and rotors.

Some pics from today:

Cleaned the front side of engine, Used rags and brushes. For cleaning I used a mix of degreaser, spare jet A fuel and some wd40.

New OE belt and tensioner

New Nissen Rad all dialled in

Went to a friend's shop with mom's car and got to do front brakes on hoist. First time working with SBC brakes. Was able to use shops software to disable SBC for rotor and pad change. Car is a 05 320 CDI

So cthe 500E still needs work. Dabbling slowly away at it.....