E320 W124 M104 Cranks but dont fire up!!! Tested "everything"
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Newbie
Joined: Jun 2017
Posts: 1
Likes: 1
W203 C-class C 180 Kompressor 2005
E320 W124 M104 Cranks but dont fire up!!! Tested "everything"
Hi!
I am new in here but this forum helped me a lot already...
I am from Brazil and work on a Mercedes-Benz Dealership and I use to make some jobs at home...
Now I am working at home on a E320 W124.032 with the M104.992 that cranks but don't fire up...
I searched on the forum and found a lot of post about this problem but none with the exactly same problem.
this is what I am done untill now....
1- I opened all the engine wiring lookind for something wrong and found nothing
2- I looked the OVP and changed it
3- I changed the Crankshaft sensor and tested it on the ECU connector and readed RPM between pin 29 and pin 30 that means that the sensor works and the ECU read RPM.
4- the fuel injector pulse and the fuel relay works when I crank the engine
5- the coil have 12v but the ECU dont send the negative signal to the coil
6- It dont have spark on any coil
7- I verified all the positive and negative wiring on the ECU connectors, all OK
8- I installed the OVP, ECU and Coils from a working w124 on it and it didnt fire up
9- I installed the OVP, ECU and coils from the non working car in another car and that car worked
The problem is that the ECU does not send a negative signal to the coils and it has no spark
I would be grateful if anyone had any idea what it could be.
P.s. I do not have the cables to read the DTCs for this E320 and sorry for the bad English.
Thanks for Everything!
I am new in here but this forum helped me a lot already...
I am from Brazil and work on a Mercedes-Benz Dealership and I use to make some jobs at home...
Now I am working at home on a E320 W124.032 with the M104.992 that cranks but don't fire up...
I searched on the forum and found a lot of post about this problem but none with the exactly same problem.
this is what I am done untill now....
1- I opened all the engine wiring lookind for something wrong and found nothing
2- I looked the OVP and changed it
3- I changed the Crankshaft sensor and tested it on the ECU connector and readed RPM between pin 29 and pin 30 that means that the sensor works and the ECU read RPM.
4- the fuel injector pulse and the fuel relay works when I crank the engine
5- the coil have 12v but the ECU dont send the negative signal to the coil
6- It dont have spark on any coil
7- I verified all the positive and negative wiring on the ECU connectors, all OK
8- I installed the OVP, ECU and Coils from a working w124 on it and it didnt fire up
9- I installed the OVP, ECU and coils from the non working car in another car and that car worked
The problem is that the ECU does not send a negative signal to the coils and it has no spark
I would be grateful if anyone had any idea what it could be.
P.s. I do not have the cables to read the DTCs for this E320 and sorry for the bad English.
Thanks for Everything!
Newbie
Joined: Jun 2025
Posts: 1
Likes: 0
Hi!
I am new in here but this forum helped me a lot already...
I am from Brazil and work on a Mercedes-Benz Dealership and I use to make some jobs at home...
Now I am working at home on a E320 W124.032 with the M104.992 that cranks but don't fire up...
I searched on the forum and found a lot of post about this problem but none with the exactly same problem.
this is what I am done untill now....
1- I opened all the engine wiring lookind for something wrong and found nothing
2- I looked the OVP and changed it
3- I changed the Crankshaft sensor and tested it on the ECU connector and readed RPM between pin 29 and pin 30 that means that the sensor works and the ECU read RPM.
4- the fuel injector pulse and the fuel relay works when I crank the engine
5- the coil have 12v but the ECU dont send the negative signal to the coil
6- It dont have spark on any coil
7- I verified all the positive and negative wiring on the ECU connectors, all OK
8- I installed the OVP, ECU and Coils from a working w124 on it and it didnt fire up
9- I installed the OVP, ECU and coils from the non working car in another car and that car worked
The problem is that the ECU does not send a negative signal to the coils and it has no spark
I would be grateful if anyone had any idea what it could be.
P.s. I do not have the cables to read the DTCs for this E320 and sorry for the bad English.
Thanks for Everything!
I am new in here but this forum helped me a lot already...
I am from Brazil and work on a Mercedes-Benz Dealership and I use to make some jobs at home...
Now I am working at home on a E320 W124.032 with the M104.992 that cranks but don't fire up...
I searched on the forum and found a lot of post about this problem but none with the exactly same problem.
this is what I am done untill now....
1- I opened all the engine wiring lookind for something wrong and found nothing
2- I looked the OVP and changed it
3- I changed the Crankshaft sensor and tested it on the ECU connector and readed RPM between pin 29 and pin 30 that means that the sensor works and the ECU read RPM.
4- the fuel injector pulse and the fuel relay works when I crank the engine
5- the coil have 12v but the ECU dont send the negative signal to the coil
6- It dont have spark on any coil
7- I verified all the positive and negative wiring on the ECU connectors, all OK
8- I installed the OVP, ECU and Coils from a working w124 on it and it didnt fire up
9- I installed the OVP, ECU and coils from the non working car in another car and that car worked
The problem is that the ECU does not send a negative signal to the coils and it has no spark
I would be grateful if anyone had any idea what it could be.
P.s. I do not have the cables to read the DTCs for this E320 and sorry for the bad English.
Thanks for Everything!
Out Of Control!!
Joined: Apr 2019
Posts: 11,924
Likes: 6,776
From: Silicon Valley
W212 MY'14 M276-3.5NA @75kMi
CRANK NO START
Brazilian troubleshooting is spot on:
This has to be related to Drive Authorization System aka. DAS !
What's upsetting security:
a bad key...
or any foreign modules not coded to chassis
or networking down issue
- ECU + CKP were proven good
- Coils have 12V but no pulse
- Fuel injectors are proven active.
This has to be related to Drive Authorization System aka. DAS !
What's upsetting security:
a bad key...
or any foreign modules not coded to chassis
or networking down issue
Last edited by CaliBenzDriver; Jun 5, 2025 at 12:06 PM.
