Volkswagen: vw passat 1.8se 20valve 1999, engine management system, electronic control unit

Question
haynes manual.when starting, the 3 letters on the dash which refer to the engine management system are not lighting up all the time,so the car wont start.I have to keep turning the key on and off until i get the 3 letters lit.I took it to a local garage for a diagnostic and was told i needed a new "ecu" but the mechanic was not 100%.He then said they cost about £500.I'll pay it if i have to but its a lot if its not that.hope you can help

Answer
Hi Stuart,

Although you had a diagnosis for a new Electronic Control Unit from your garage...the Engine Management System (EMS) relies on relays, proper grounding (Earth), etc.

The best thing you can do for yourself is to get it to VW.  They have the COMPLETE diagnosis system for the EMS.  


Perhaps it's your ignition switch.

I'm not sure what diagnostic equipment the local garage is using, but I find it's extremely rare that they have the piece of equipment specifically designed to troubleshoot the Polo/Passat/Jetta EMS.

I'd suggest going to the dealer first.   If it's the ECU, don't get a new one,  you will be able to find one online.

Best of Luck,

Ron