91 300CE-24 California Diagnostics
#1
Thread Starter
Junior Member
Joined: Dec 2016
Posts: 32
Likes: 0
From: San Diego, CA
1991 300CE & 1995 E320 Wagon
91 300CE-24 California Diagnostics
Greetings Everyone!
Well I decided to finally tackle the underhood problems with my coupe. Check Eng light on, hard starting, poor idle, etc..
So I built a handy-dandy code reader (a little plastic box, a mom on/off switch, 12v LED, a few wires w/ banana plugs).
I went out to the coupe this AM and plugged the code reader into the appropriate pins of the 16-pole diagnostic connector (next to the battery), turned the key to ign, pushed the code reader button and nothing...
after a bit of probing I found that "pin 16" (+) is not used on my coupe's connector (there is no pin). I switched the reader's 12v input directly to the battery and still nothing.
California cars do have a LED built into the diagnostic connector and pushing it's button also does nothing. I seem to recall on my '88 (M103) 300CE having to jump a couple of pins on the X11 connector (round- mounted on LH fender) to power up the diagnostics?
Though I've found and read a ton of info today; the Cali cars appear to be a bit different. I did DL and peruse "Fault Code Manual for Mercedes-Benz
Analog Systems 1988-1997, Digital Systems 1993-2000" and couldn't find a definitive procedure for California cars.
Any assistance/ideas appreciated,
Chad & Janet
Well I decided to finally tackle the underhood problems with my coupe. Check Eng light on, hard starting, poor idle, etc..
So I built a handy-dandy code reader (a little plastic box, a mom on/off switch, 12v LED, a few wires w/ banana plugs).
I went out to the coupe this AM and plugged the code reader into the appropriate pins of the 16-pole diagnostic connector (next to the battery), turned the key to ign, pushed the code reader button and nothing...
after a bit of probing I found that "pin 16" (+) is not used on my coupe's connector (there is no pin). I switched the reader's 12v input directly to the battery and still nothing.
California cars do have a LED built into the diagnostic connector and pushing it's button also does nothing. I seem to recall on my '88 (M103) 300CE having to jump a couple of pins on the X11 connector (round- mounted on LH fender) to power up the diagnostics?
Though I've found and read a ton of info today; the Cali cars appear to be a bit different. I did DL and peruse "Fault Code Manual for Mercedes-Benz
Analog Systems 1988-1997, Digital Systems 1993-2000" and couldn't find a definitive procedure for California cars.
Any assistance/ideas appreciated,
Chad & Janet
Last edited by Slick201; 06-25-2017 at 08:14 PM.