CEL/Headlight & Running Light issues/Headlight Washer

[MBchap]

My '94 E500 has been a painful, expensive whack-a-mole experience. I've owned the car for 3 years and have only driven it for about 3k, including two cross country trips. It now has 156k on the clock and I have meticulous contemporaneous maintenance records kept by the PO, who was an aircraft pilot and mechanic. Regardless, I knew that there would be deferred maintenance and, sure enough, so far:
Upper wiring harness
Lower wiring harness
Power steering pump
Hydraulic suspension R&M (now has a faint "clunk" when driving over cracks in the road :x)
Valve cover gaskets (still leaks)
Tie rod ends (still get vibration)
A/C compressor
Radio now malfunctions (OEM replacement by PO in 2014)

I cannot with any confidence drive to the grocery store without something else breaking. Case in point, when I came out of the store and started the car, the CEL came on. Also, light for blown bulb also came on. Blown bulb light no longer is lit but bulb(s)are still out. So now:
With headlight switch on, right front headlight and right running light are not on. With the switch in running light position, the right front headlight comes on (right running light off) and the left headlight washer arm activates. CEL is still lit and visual check of vacuum hoses is ok. Engine runs fine.
Has anyone else had any such symptoms bundled together? I guess that I need a code reader to see what faults show up, right? If the codes tell what is not working, how does one determine why these issues continue to crop up?

I have run MBs for all my adult life and never had the volume of issues or expense that I have experienced with this one car. It makes my 2001 Range Rover seem like an engineering marvel and the most reliable vehicle ever created...

 

[gsxr]

Sorry to hear you are having such trouble with the car. Some of what you list (harnesses, PS pump, etc) are typical failures to expect if there is no record of them being repaired/replaced in the past. If the valve covers were not done properly with OE gaskets, I'm not surprised they are leaking again... especially if any sealant was used previously. HOWEVER, there are several other oil leak points which can appear to be from front area of the valve covers, so further investigation may be warranted before condemning the VC's. Tie rod ends generally do not cause vibration, that is typically wheels/tires or possibly steering shock, or even engine mounts.

Anyway: The CEL is easy to work with. The top 3 sticky threads at this link should get you in the right direction. Use the built-in blink code reader in front of the CAN box to see what code is causing the CEL. As noted in those threads, this blinker only shows DM codes; to get more specific code data you still need a hand-held blinker box to check each of the other 5 powertrain modules separately. The CEL primarily tells you about emissions faults, which may or may not be a big deal - for example the engine can run flawlessly with something like the air pump not working right.

For the headlight / wiper issues... something is definitely amiss there. I'm not sure what exactly would cause this but some wild guesses would be the rotary headlight switch, or maybe wiper combination switch on the steering column? Might also be a poor ground somewhere or bad connection at a fuse, easy to pull one fuse at a time and clean the contacts just to rule that out. Might need to spend some time poring over the ETM schematics to nail this one down unless you want to throw parts at it, neither of which are fun options.

 

[MBchap]

Well, that seems to be my problem. These vehicles are so complex that faults can be a number of items for each issue. For mortals like me, that means mechanics throwing parts at it for $$$. Dealerships won't work on them. As for schematics, I don't have a clue understanding them no matter how much I study them. I don't get it. Since the electrical issues happened with the same turn of the key, is it possible that the CEL issue is an electrical and not a vacuum leak, diaphram, etc.?

I did order the scanner and box. When I push the button in front of the CAN box, the 4 lights up but no blinking so I don't get that either. Gsxr, I've read a number of your posts and I appreciate your help and reply.

 

[TerryA]

Sorry to hear about your bad luck but it looks like some of the major issues have been corrected. Harnesses & PS pump ect;. These cars a generally very reliable and are pretty bullet proof but can be PITA sometimes. You say the PO had great records but was he a DIY guy or just paying a Tech when something broke?

If you have the talent DIY is a great way to go on some of the E500E issues to save $$$ but some problems need a good Tech.
I hope that a member in your area of Dallas could recommend a really good Tech for you. The right guy should be able to right your Q-Ship for you.

Myself, I do what I can but won't hesitate to use a Tech when it's over my head. Fortunately here in SoCal there are plenty of Techs that know these cars. Just remember these cars are not for the "faint of heart" or "the lite of wallet".

I wish you the best and hope you get straightened out soon.

 

[nocfn]

Keep the faith fellow Texan (we all got here as soon as we could)


You have a fellow member close to you with plenty of m119. Keep at it, you will get it sorted and nothing beats that feeling when you do.

 

[gsxr]

Well, that seems to be my problem. These vehicles are so complex that faults can be a number of items for each issue. For mortals like me, that means mechanics throwing parts at it for $$$. Dealerships won't work on them. As for schematics, I don't have a clue understanding them no matter how much I study them. I don't get it. Since the electrical issues happened with the same turn of the key, is it possible that the CEL issue is an electrical and not a vacuum leak, diaphram, etc.?

The CEL could be due to electrical or mechanical issues. We need to get the code number to find out. The other electrical glitch may be related, or could be coincidence - can't say without additional data.

I did order the scanner and box. When I push the button in front of the CAN box, the 4 lights up but no blinking so I don't get that either.

Hrmmm. Make sure the ignition is turned to position 2 (all warning lights on in the instrument cluster) and that you hold the button for 2-3 seconds. This should trigger the blink readout. If not... it's possible your DM has failed.

 

[MBchap]

Thanks for replies guys. I'm just reeling a little. I did hold the button down for at least 10 sec with the key in position 2. No blink, just steady #4 light. Let me try it again now...nope, just steady light #4. Is it normal to hear a faint "alarm" noise coming from the engine when the key is turned to position 2? FWIW, more issues... main key will no longer turn in the ignition tumbler (?). Have to use the valet key now. Also, sometimes when I close the passenger side door (with no key in the ignition), it automatically locks. Ask me how I know... Is this car haunted?

 

[gsxr]

Thanks for replies guys. I'm just reeling a little. I did hold the button down for at least 10 sec with the key in position 2. No blink, just steady #4 light. Let me try it again now...nope, just steady light #4.

To read codes, you need to hold the button for 2-3 seconds only. After reading each, if you hold it for 6-7 seconds that should clear each code (separately, one at a time). It's time-sensitive, and after clearing you need to drive the car before re-checking. Typically the CEL will remain off for a couple of starts before coming back on (assuming there is a persistent failure), if the codes will clear but the CEL triggers immediately, the DM is either really unhappy about the code, or the DM is acting up.

Is it normal to hear a faint "alarm" noise coming from the engine when the key is turned to position 2?

Yes, the ETA does a little dance and produces clicking and buzzing noises when the key is in position 2.

FWIW, more issues... main key will no longer turn in the ignition tumbler (?). Have to use the valet key now.

THAT is worrisome - but it's good you can still turn the valet key! Assuming the tumbler has never been replaced, order a new VIN-coded tumbler from the dealer ASAP. It's a 5-minute swap as long as you can still get a key to turn, if the tumbler seizes it could be a $1k repair bill to drill / destroy the assembly to get it apart. Then, use the new key that comes with the new tumbler as the daily-use key.

Also, sometimes when I close the passenger side door (with no key in the ignition), it automatically locks. Ask me how I know... Is this car haunted?

Uh... yeah, that ain't right. Something is wonky with the central locking. Good news is, the system is relatively simple to diagnose... bad news is, the diagnosis is time consuming. If you have any kind of remote locking system (alarm, etc) that would be the first thing I'd check out.

 

[nocfn]

CEL/Headlight & Running Light issues/Headlight Washer

Man just replace that tumbler, best 125 you ever spend.( don't forget the tool to make job easy )

 

[MBchap]

Whether 2 seconds, 3 seconds or 10 seconds, just steady red #4 with the button. Never seen a blink yet and CEL is still on so I guess we'll see what the tester/box will tell me. I can drive the car in daylight but grounded at night due to missing headlight. Funny that the bulb trouble light went away on the dash...

 

[gsxr]

Whether 2 seconds, 3 seconds or 10 seconds, just steady red #4 with the button. Never seen a blink yet and CEL is still on so I guess we'll see what the tester/box will tell me. I can drive the car in daylight but grounded at night due to missing headlight. Funny that the bulb trouble light went away on the dash...

If the LED (#4) is always lit up when the key is in position 2... and never turns off when you hold down the button... your DM miiiiight have died. I'm not quite ready to condemn it yet. On the bright side, used DM's are cheap since they are a relatively rare failure.

The hand-held blinker may not provide any more useful info (from pin 4 / DM module) as it essentially duplicates the function of the built-in button+light you have been using thus far. However, the hand-held unit will let you check codes on the other modules to see if there is anything that might make the DM unhappy. If you bought the hand-held reader with 1mm pins, make sure you are using the correct sockets, they are hard to read (more details in the threads I linked earlier). If you bought the type with 4mm pins, you'll need a separate breakout box which makes the job easier, but adds a few bucks to your tool investment total.

Is there any forum member near Dallas who might have a digital scanner / Star SDS to plug in?

 

[MBchap]

Thanks Terry. PO was a crop duster pilot who built a crop dusting company up, maintaining a fleet of planes and eventually retiring. I have a log book of the mostly DYI items and the occasional Tech help with his evaluations of the quality of the job that the tech did, all recorded contemporaneously in the log book for 20 years. I got a decent price, no doubt built around the proposition of the maintenance items that he knew were on the horizon. When I include Gerryvz's estimate of deferred maintenance costs on a E500E purchase with the purchase price, it looks like I'm right on plan (but it seems like it's taking forever to get it sorted having driven 3k in 3 years ownership!). Thanks again.

 

[gerryvz]

My experience with these types of electrical issues usually comes down to something very very basic, and thus easily fixed.

It sounds to me like there is a main ground that is corroded or otherwise wonky. Circuits are getting closed that shouldn't be.

Please check the connections to your battery in the trunk to ensure the battery is in good condition, and that there is no corrosion on the terminals. Tighten the terminals after cleaning them.

Check all fuses (rotate them in their sockets with your fingers) in the fuse box.

The key ground points you need to check are behind the CAN box under the hood; under the fuse panel; behind the instrument cluster; and underneath the center console wood.

In the Dallas area, I recommend you speak with Louden (a local MB/German garage there) to see if they can/will diagnose your issues.

Cheers,
Gerry

 

[MBchap]

I was able to get the reader tool and have the following codes:
Pin 4 13
Pin 6 13,26
Pin 7 6,2,5
Pin 8 7,5,6
Pin 14 Continously lit
Pin 16 30
Pin 19 5,9,4
Pin 30 2,4

I cleared all the codes that I could but could not clear pins 14,16,19 and 30. Odd that Pin 14 is lit as soon as I plug into the box and stays lit. I'll go for a drive and see what codes return. Good times.

 

[gsxr]

I was able to get the reader tool and have the following codes:
Pin 4 13
Pin 6 13,26
Pin 7 6,2,5
Pin 8 7,5,6
Pin 14 Continously lit
Pin 16 30
Pin 19 5,9,4
Pin 30 2,4

I cleared all the codes that I could but could not clear pins 14,16,19 and 30. Odd that Pin 14 is lit as soon as I plug into the box and stays lit. I'll go for a drive and see what codes return. Good times.

I think you have one of the numbers off... socket 14 is not used. Maybe that was #17 (EZL)? Don't worry about 16 and 30 as those are not powertrain related. Pin 19 may require starting the car afterwards to fully clear.

More info in the attachments at this thread: http://www.500eboard.com/forums/showthread.php?t=2996

 

[MBchap]

It is definitely pin 14 that is lit - just checked it for the fourth time just now. Odd that with the button tester in the CAM box, LED # 4 has a continuous light when it should blink when pressed, right? No codes at all on 17 and now 19. The CEL is no longer illuminated. I'll go for a ride and see what happens...

 

[Stevester 500E]

I had a very good MB mechanic tell me how MB was ahead of their time with individual diagnostic modules etc. I agree to some extent. However, some of the DTC's end up being the story of which came first, the chicken or the egg. One example, the AC compressor doesn't engage and you get the DTC code for that...
But where is the darn code that tells you the Base Module is bad !

There are other which came first, the chicken or the egg scenarios.

Well, that seems to be my problem. These vehicles are so complex that faults can be a number of items for each issue. For mortals like me, that means mechanics throwing parts at it for $$$. Dealerships won't work on them. As for schematics, I don't have a clue understanding them no matter how much I study them. I don't get it. Since the electrical issues happened with the same turn of the key, is it possible that the CEL issue is an electrical and not a vacuum leak, diaphram, etc.?

I did order the scanner and box. When I push the button in front of the CAN box, the 4 lights up but no blinking so I don't get that either. Gsxr, I've read a number of your posts and I appreciate your help and reply.

 

[Stevester 500E]

I believe 19 requires that you start the car, the car will still illuminate the CEL, turn it on for the second time and the CEL light will clear- I believe, correct me if I am wrong Dave?

I think you have one of the numbers off... socket 14 is not used. Maybe that was #17 (EZL)? Don't worry about 16 and 30 as those are not powertrain related. Pin 19 may require starting the car afterwards to fully clear.

More info in the attachments at this thread: http://www.500eboard.com/forums/showthread.php?t=2996

 

[MBchap]

So pin 19 was cleared and the CEL off when I started the car. I looked for the grounds under the CAN and the fuse box but could not locate either. Battery is newer and terminals are tight. Turned all fuses a little. So I started the car and turned on the lights. Right headlight not on and left wiper running. I turned on the brights and there was a small pop and a puff of smoke from somewhere left front of the engine. Something on the lighting circuit arcing? No fuses are broken. With the high beams, the wiper goes off and both high beams are functioning. I am in Minneapolis now, moving the car back to Texas in Sept. Does anyone know an indie here who knows these cars? I can't drive it back this way so might have to take it to one of the local MB dealers if can't find an indie....

 

[MBchap]

So mystery solved. Mechanic who replaced A/C compressor must have unplugged left headlight and headlight wiper motor (maybe moving it out of the way?) When reconnected, he got them mixed up and plugged the motor into the light plug and vice versa. Must be voltage diff b/c fried wiper motor. Frustrating and expensive.

 

[DerFuror]

So mystery solved. Mechanic who replaced A/C compressor must have unplugged left headlight and headlight wiper motor (maybe moving it out of the way?) When reconnected, he got them mixed up and plugged the motor into the light plug and vice versa. Must be voltage diff b/c fried wiper motor. Frustrating and expensive.

You’ve been punished for over a year by that.

Thanks for crossing the barbed wire for us on this one. We’ve learned an important reality that the two plugs are evidently interchangeable. This potential for plug interchangeability is GOOD to know from a troubleshooting/diagnostical standpoint.

The first step when investigating these symptoms is to Check for Correct Plug Connections.

Admins should consider moving this thread to Troubleshooting & Diagnostics.

 

[MBchap]

Nocfn and others,

I had the dreaded key stuck in the ignition situation. Unfortunately, the car was running and I could not turn it off! After about 10 min. (seemed like an hour) of fumbling with the key, I finally was able to turn the car off and remove the key. Immediately ordered the tumbler and removal tool kit (need to take other components out of the dash) and, thanks to Gerry's (and others) posts, was able to change it out in minutes. Done! Old tumbler was broken in half as others have experienced. Thanks fellas. BTW, what is the best/easiest/safest way to turn an E500 off if one couldn't get the key out of the ignition...?

 

[MBchap]

...besides banana in the tailpipe...?

 

[gsxr]

...besides banana in the tailpipe...?

Banana would be my first choice of course (two required).

I think the cleanest method to kill a running engine would be to remove the rear passenger seat and unplug the green fuel pump relay.

 

[Klink]

Banana would be my first choice of course (two required).

I think the cleanest method to kill a running engine would be to remove the rear passenger seat and unplug the green fuel pump relay.

Also, if you know the underhood component layout, unplug the crankshaft position sensor at the EZL ignition control unit.