CMP (cam position sensor) issue

[NorDigg]

Have made a read out of codes from Can data modules and got failure code
For CPM sensor in module fuel injection and ezl ignition module. I have replaced the sensor so i dont think there is any problems with is. I think the
coaxial cable is bad. I contacted MB and asked for this cable and they
said that the part can not be purchased. The cable is included if i buy a complete engine harness. I have already replaced the engine harness by making own cables. I can not buy a complete engine harness when i only need the CPM sensor wire. Anybody there knows if it can be bought separately or how i can solve the problem ? Maybe i can make a new cable if i have the correct sockets for both ends of the cable.

 

[500AMM]

Hello.

I am not an expert on this, but a good info to add on such questions is the model year of your car and the VIN.

Welcome to the board BTW.

Cheers
-arnt-

 

[NorDigg]

My car is MB 500E -93. Engine 119.974

 

[gsxr]

The cam position sensor cable is integrated into the engine wiring harness. AFAIK, it is not available separately. However if the insulation is not damaged and the cable tests out OK with an ohm meter, the cable is not likely to be the problem.

What is the exact code (or codes) from the EZL?

Have you checked the air gap on the sensor per the factory manual and adjusted the shims as necessary?

 

[NorDigg]

Thank´s gsxr for yor quick reply.

Error codes from modules. Readout made with home made LED equipment:

Fuel injection: Pin 6, error 8, CMP sensor signal, open, short circuit
EZL ignition: Pin 17, error 6, CMP sensor defective

I have difficulties to measure the resistance from the connector on the sensor side. The resistance is not stable and it is har to get proper connection. I have measured the value on the sensor and it seem to be okay according to the service manual so i believe still that i have play in the cable. Today i will buzzer the cable to state the problem. Anyway if it is the cable, how can i fix it if the cable is not avaliable, any good ideas is appreciated

 

[gsxr]

If the cable is bad, you'll need to replace the harness - I don't know of any other alternative. A new harness is ~$650 USD here in USA. Sometimes good used ones (late date code) show up for less. On a budget, a 400E/E420 harness may work, good used ones show up at times for under $200 USD.

 

[NorDigg]

I have found the solution. I have bought the cable with the CMP socket. Art no: 1295402281. The cable is not shown in the MB 500E parts catalogue but this cable is is used in other MB cars so it is avaliable as a repair kit without the connector to the other side of the cable.

 

[gerryvz]

Thanks for the update -- this is useful information.

Can you post a photo of this cable?

Cheers,
Gerry

 

[gsxr]

I'd like to see the other end of the cable... not sure how you can splice coax, unless it comes with the proper connector on the other end too...?

 

[NorDigg]

Picture of the cable enclosed.

/Andreas

 

[gerryvz]

Thank you!

 

[Oldcar]

I somewhat recently replaced cmp sensor....... and cleared code

just tested pin 17 again and still getting code 6 cmp sensor (L5/1)defective...upper harness was replaced a few years back..
I do see some oil seapage on the wires in that area? But wires seem ok...and sensor is in very tight! Cleaned plug and socket as well 2x.

 

[Oskichohfi]

Hello everyone.

Can anyone have an idea of what's going on?

I have an E420 that works perfectly. Engine is idling very well and when it is running it responds on time. The car is very good.

But after getting hot, when I try to start it again, it's hard to pick up.

Could it be the CMP sensor?

Accused in hht L5/1.

Thank you all.

 

[gsxr]

If you clear the fault code for L5/1, does it return the next time the problem occurs?

Try measuring the resistance of L5/1 cold, and compare to the measurement when hot, when the problem is occurring / engine not running correctly.

 

[Oskichohfi]

I changed the sensor for another one that had from my c36.

The same thing happened. It gave the same error LH - fault 8. L5/1 and the car sometimes takes a long time to pick up.

I checked the whip and it's good.

I haven't measured the resistance yet.

 

[gsxr]

If a different sensor had the same fault, the sensor may be ok.

What is the date code on the upper engine wire harness? Has this been replaced?

 

[Oskichohfi]

Now I don't know how to tell you,

But I saw that the harness is modern. Very good wires.

Engine whip and body throttle harness.

 

[Oskichohfi]

Hello everyone,

I still have the problem of L5 and L5/1, but I have news.

Today I was able to read the EZ1 with the car running.

I filmed the instant errors that occur. I found it very strange. It keeps oscillating a lot of errors, maybe some whip short or bad EZ1?

Has anyone ever seen something similar?

The videos are in this link because they were grids to post. If anyone can help I will be grateful.

M119 HHT EZ1 - Google Drive

drive.google.com

 

[gsxr]

That is a very unusual result. Never seen anything like that. If you can upload the videos to YouTube, and post the links here, that will make it easier for other people to view the videos without downloading.

What part number is the EZL currently installed? Do you have a spare EZL to swap in for testing?

 

[Oskichohfi]

I'll do that,

The number is 0155456032. I'll see if I can get one.

 

[gsxr]

Ohhhh! 015-545-60-32 is the wrong part number... that is for a 4.2L engine. Had your 500E been running normally with that EZL in the past?

Definitely locate a 5.0L EZL to test with.

EDIT: Just realized you are not the OP, who had a 1993 500E... the 015-545-60-32 EZL is correct for your E420, assuming your chassis is after B965057. But yes, try to find another EZL of the same part number.

 

[Oskichohfi]

M119 EZ1 Fault

Share your videos with friends, family, and the world

www.youtube.com

 

[Oskichohfi]

Ohhhh! 015-545-60-32 is the wrong part number... that is for a 4.2L engine. Had your 500E been running normally with that EZL in the past?

Definitely locate a 5.0L EZL to test with.

EDIT: Just realized you are not the OP, who had a 1993 500E... the 015-545-60-32 EZL is correct for your E420, assuming your chassis is after B965057. But yes, try to find another EZL of the same part number.

No. This car here is an E420.

My 500e has another EZ1

 

[Oskichohfi]

Are the parts numbers of ez1 that work only these?

0135456332
0145454532
0155456032
0155451332

 

[gsxr]

Are the parts numbers of ez1 that work only these?

0135456332
0145454532
0155456032
0155451332

For your 1994 E420, most likely only 015-545-60-32 will work correctly. The first two part numbers in your list are for older 4.2L engines with closed-deck block.

The last part number is not an EZL, it's the DM used on USA models to control the CEL.

 

[Oskichohfi]

For your 1994 E420, most likely only 015-545-60-32 will work correctly. The first two part numbers in your list are for older 4.2L engines with closed-deck block.

The last part number is not an EZL, it's the DM used on USA models to control the CEL.

View attachment 232816

ok. thanks!!

I'll look for the same one around here.

 

[Oskichohfi]

Hello everyone.

Problem solved.

I guessed what was happening.

At some point in the life of the car, someone with a lot of intelligence did the favor of grounding the 85 pin of the starting relay that is behind the instrument panel, on the column. Negative W1.

The car was shorted. And it drove EZ1 crazy.

Causing intermittent errors to appear and the car did not start a few times.

I took out the wire they put and connected directly the 30 in 87 eliminating the immobilizer that is at the passenger's foot.

Problem solved.

 

[gsxr]

WOW. Good job locating the root cause! I wouldn't have expected that. Also, you'd think the person who added the "wrong" wire would have noticed that the car didn't run properly afterwards!!

 

[Oskichohfi]

I don't think so.

Because the car worked normally.

I don't know how.

Only some matches that didn't catch, and recorded an error in the L5 and L5/1 sensor.

For the rest, the car is working.

Another learning


Thank you very much.