Electrics: 850: How to make a Flash Code Reader, for Dummies

[DaveNP]

You can get plugs, or plugs with bare wires, on ebay, or if you're buying all the other bits try CPC, if you spend enough you won't have to pay postage.

CPC website is down at the time of posting but they had a plug last time I looked, I had thought to get a plug and a rotary switch to try to see if it could check the other systems too like the old fly lead system on the 850.

[Mr Thirsty]

David,

Thanks for the reply. I managed to order the other bits from cpc before the wb site went down, but couldn't find a plug on their site. I will hunt one down on ebay or amazon.....

Happy motoring!

[Ross 63]

I have Vol-FCR but my car is a 96 850 T5, so I can read ABS, EEC, instruments etc from the laptop, but not the Motronic 4.3 ECU. I made a fault code reader for the engine ECU from a small plastic housing, an old OBDII cable, and a momentary push switch. Looks slightly tidier than the paperclip version, but ultimately does the same job:



I left my superglue in my other car, so I haven't screwed the box together yet until I glue the LED in place. Tested it out and it works perfectly. Pleased to get a 1-1-1 flash code telling me that no faults are logged on the Motronic 4.3 ECU.

For anybody wanting to do their own:

1. remove the pcb from inside the OBDII plug.
2. Solder the following->
a: Pin 16 to positive leg of LED
b: Pin 3 to negative leg of LED AND one side of the momentary push switch. I soldered two wires onto pin 3 for this
c: Pin 5 to the other side of the momentary push switch.

That's it. I'm an absolute amateur at soldering and it took me about 40 minutes start to finish. Be sure to route your wires into the box before soldering to the switch and LED.