Need help with 400E code

[martin400]

Hello

I am new to the forum and need a bit help with my 1993 400E, which is my hobby car.
I was driving the car the other day and CEL came on.
I drove it back to garage and i could feel slight hesitation from the engine when hitting the throttle from stop light.
I decided to check fault codes, i have an 8 pin connector (part n. 1265459740) i hold the button for 3 sec and only blink code i could get was number 18.
I tried to check the files and information uploaded here on the forum and the code 18 seems to be no data transmission from ignition control module? Am i correct reading the code? Thank you

 

[emerydc8]

The built-in blink code tester will only give you information about emissions-related problems. There are a number of other modules that will not illuminate the CEL although if your engine hesitation started at the same time your CEL illuminated that is a good place to start until you get a tester on it. Check out this post for more information on diagnostics. You should get a blink code tester or make one. There is a 38-pin canon plug next to the tester on the car. You can unscrew the cap to access it.

Thread 'HOW-TO: Checking DTC's (Diagnostic Trouble Codes) on the 500E/E500'
FYI - HOW-TO: Checking DTC's (Diagnostic Trouble Codes) on the 500E/E500 | Troubleshooting and Diagnostics

 

[gsxr]

Only USA-spec cars have a CEL. Are you located in Estonia or just using a VPN?

Anyway - You were looking at the codes for the LH module (fuel computer), not the DM (Diagnostic Module) codes. As @emerydc8 noted above, each module must have codes checked separately with a hand-held blink code reader.

The built-in LED+button will only show codes for the DM (CEL). Code 18 on the DM is for "Adjustable camshaft timing solenoid, open/short circuit". Is the engine wiring harness original, or has it been replaced?

 

[emerydc8]

The link to the pre-built code reader shows no results. If you want to build a home-brew reader this might help. Or maybe someone else has a link.

K6JRF Auto Page

 

[gsxr]

The link to the pre-built code reader shows no results.

Thanks for the heads-up, Jon! Apparently "porscheapriliafan" doesn't make them anymore. I updated the link to show generic search results for the OBD-1 readers.

 

[martin400]

Thank you for the quick replies.
Yes i am actually loacated in Estonia.
The car is US spec but was purchased from Tokyo, i have no idea if the harness has been changed or not.
What should i check when it comes to cam solenoid? Or i could suspect the worst that harness itself needs to be replaced.

 

[R129 UK]

Or i could suspect the worst that harness itself needs to be replaced.

HOW-TO: Determining the age of your engine wiring harness | "HOW-TO" Tutorial Articles

See attached photos. The manufacturing date of the harness will be on the tag. If the date is 1996 or newer, the harness is not original. The new replacement harnesses made from at least 1998-up (possibly earlier) have improved insulation and do not fail after a few years like the originals did...

www.500eboard.co

 

[gsxr]

Thank you for the quick replies.
Yes i am actually loacated in Estonia.
The car is US spec but was purchased from Tokyo, i have no idea if the harness has been changed or not.
What should i check when it comes to cam solenoid? Or i could suspect the worst that harness itself needs to be replaced.

See the link above posted by @R129 UK and check the harness first. If you can't find the date codes, skip down to the photos in post #22 to see what a bad harness looks like (insulation missing or crumbling off the copper wires).

If the harness has been replaced (late datecode, good insulation) then proceed with further investigation. Next question - had the car been running fine and recently acted up? Or did you just buy the car and find it does not run properly?

 

[martin400]

Thank you, i will check the harness.
I havent driven it much, got the car last autumn and it was driving fine before i garaged it before the winter.

 

[martin400]

I checked the harness and it was made in 1993
I tried to checked the code again but it was gone, also CEL didnt come on.
I didn´t have time to drive the car but but the engine was on its working temperature.
I think i must still buy the diagnostic tool to check my 38pin connector then.

 

[martin400]

I have received my diagnostic tool last week and i tried to use it yesterday.
Unfortunately i figured out that half of my 38pin connector sockets were empty so i couldnt use the tool.
I checked that the tool powered up normally when i used 12v battery, so the tool is good.
See the picture attached of my 38 pin connector.
Do i have to buy and install the new 38pin connector to my car or i have other options?
Thanks

 

[R129 UK]

What tool did you buy?

It might be that the 38 pin cable is not fully populated. You can check the continuity at the pins on each end of the cable with a DVM.

 

[gsxr]

I have received my diagnostic tool last week and i tried to use it yesterday.
Unfortunately i figured out that half of my 38pin connector sockets were empty so i couldnt use the tool.

This is normal. There are only 7-9 total systems in the 124 which can provide fault codes (depending if the DM and IRCL modules are present). The other sockets will be empty.

I checked that the tool powered up normally when i used 12v battery, so the tool is good.
See the picture attached of my 38 pin connector.

Yep, your connector looks normal for a USA-spec car. Click the link @emerydc8 shared back in post #2 for details. Look at the attachments to that post.

Do i have to buy and install the new 38pin connector to my car or i have other options?

Your 38-pin connector looks perfect. What diagnostic tool are you using? It MUST support OBD-1 systems on the early 1990's Mercedes to be of any use. Otherwise, use an analog blink code reader as shown in the post linked previously.

 

[martin400]

I bought this one attached.

 

[gsxr]

I bought this one attached.

That should work! Make sure to get the pins into the correct sockets... follow the directions in the thread linked back in post #2. Use the PDF file uploaded there as well.

 

[martin400]

Yes, i think i tried wrong sockets, i will try again, thank you.

 

[martin400]

Finally i was able to find some time and came up with a bunch of codes:
4 socket - 4 and 25
7 - 2,7,11
8 - 5,7,9,10,11,12,13,6
19 - 18
I also took the car for a longer trip i noticed a bit idling at the stops when the engine was on working temperature.
I also noticed that it lacks midrange punch, is sluggish and and holds gear on too long, wont shift down, but when i pushed the pedal on the floor it burned tires and accelerated quite well. I drove maybe 20 miles in the city and no CEL.

 

[gsxr]

Finally i was able to find some time and came up with a bunch of codes:
4 socket - 4 and 25
7 - 2,7,11
8 - 5,7,9,10,11,12,13,6
19 - 18

Great! Now clear all those codes, drive the car for a few days, and see which codes return quickly. Focus on the new codes.

I also noticed that it lacks midrange punch,

Lack of midrange power can be the cam advance system not working correctly. This would coincide with code 18 on the DM (pin 19). If your engine harness is original with cracked / failing insulation, you MUST replace this first. It will be very obvious if the insulation is bad, click here for photos.

is sluggish and and holds gear on too long, wont shift down, but when i pushed the pedal on the floor it burned tires and accelerated quite well.

Staying in gear longer than normal at part throttle is either a mis-adjusted Bowden control pressure cable, OR something causing low power which then forces you to press the accelerator pedal further down than normal.

I drove maybe 20 miles in the city and no CEL.

It may take several drive cycles (cold start, drive until warmed up) before the CEL will show again.

 

[martin400]

Yes thank you i will try to clear the codes and check again, hope picture will look better.

 

[martin400]

I cleared all the all the old codes, drove around for some time and checked the codes again.
Now the following codes came up:
4 socket - 25 blinks
8 - 7
19 - 18

 

[gsxr]

One of your cam solenoids / magnets is either unplugged, or has a bad wire. Have you replaced that old/original engine harness yet? No point in further diagnostics until that's done.

 

[martin400]

No i havent done the harness yet. Do you recommend replace both upper and lower part?
Thank you.

 

[gsxr]

No i havent done the harness yet. Do you recommend replace both upper and lower part?
Thank you.

Definitely the upper, ASAP.

The lower needs inspection first. It's NLA so you'd have to buy a repair harness from Kurth, or rebuild it yourself. If the insulation isn't completely falling apart yet, you could leave it alone. Lower harness goes to the oil pressure/level senders, alternator, and starter only. Check the wires around the base of the oil filter housing.

 

[martin400]

Ok, thanks, i will address it asap.