Mercedes-Benz Forum banner
1 - 5 of 5 Posts

· Registered
1996 E320
19 Posts
Discussion Starter · #1 ·

I'm hoping someone has an idea that can lead me in the right direction. My 1996 320E Sedan has the check engine light on and it's not generating a code. My mechanic can't get it through inspection until they can get the code and his reader is not displaying one. He even had a colleague from mercedes check it out and he is stumped. Has this ever happened to anyone?

Recently they had to shave down the cylinder head and also they had to replace the unit for the air conditioning that's under the hood. When I got the car back it was running great except for a couple of things.

One night I took it out and the next day the battery light came on. I thought possibly my friend hadn't closed the back door hard enough so I had my dad put the charger on the battery and then I was back in business. Also before the battery was charged up I noticed on cold starts in the morning when I apply the gas the car won't move and then "wakes up" and will surge forward.

Other then the two things mentioned above the car was running great and then the check engine light popped on with no code.

We are stumped. Any clues or insight would be really helpful. I just sunk a lot of money into this car and just want to get the friggin thing past inspection.

· Outstanding Contributor , SDS Guru
1998 MB E300TD, 1997 MB E36 AMG, 2001 MB E55 AMG. 2011 BMW 335d
8,719 Posts
You need the Mercedes scanner to read all codes, particularly the ones in transmission TCM and the alarm ATA module. Any codes in both will trigger the check engine light.

No, I don't know why it's like that, an oddity that only 96 Mercedes are graced with. Yet another proof that I refuse to work on 96 cars. :D

· W210 Section Moderator
1998 E320 base sedan @ 242 kmiles
11,126 Posts
For 1996 E320 the OBD2 port connected to the Diagnostic Module (DM), and the diagnostic module communicates with the ECU (the engine computer for E320) over the CAN Bus (data signaling link). From the under-the-hood 38 pin connector, the test equipment (MB Star or equivalent) goes directly to the ECU, No CAN-bus involved.

Sometimes, the DM has problems with communication with the ECU over the CAN bus, so DM responds with "communications error", and common scanners do not support this code.

One can connect the OBD2 scanner with a OBD2 to 38 pin adapter cable (basically shifts pin 7 of the OBD2 port to pin 4 of the 38-pin connector, plus power and ground pins of course. This allows the DIRECT access to the ECU.

The other option (which is preferred) is to use MB Star or equivalent , to retrieve the codes, and any communications issues with DM and and other modules for example....
1 - 5 of 5 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.