View Full Version : Question How good are the Diagnostics? 2.0GL '95

07-07-2008, 01:46 AM
Anyone had any experience with the on board diagnostics (OBD) on a 2.0 1995 Passat (Eng Code 2E)?

Being such an early age I'm wondering if there is any information that is really (i.e. like worth knowing) usefull and availabe from the diagnostic connector? Is it worth investing in a OBD code reader or even a VAG-COM type system. If so what sort of information will I get out?

I've checked out the Ross-Tech website and it says that I'll only be able to get "engine" information from my car via VAG-COM. This may sound ignorant, but is "engine information" actually useful (or is it just going to tell me coolant temp and rpm etc?)

lpg boy
07-07-2008, 10:44 PM
I have VAG-COM which I use on my '95 passat 2.0 estate 2E.
It not only reads the engine but also ABS faults including which wheel sensor is stuffed when the light comes on or other causes. My dealer will not release a car with an ABS fault if you take it in for a reading(£40) they site their 'health and safety liabilty'
Also bear in mind , if you remove or change the distributor the ONLY way to set the ignition timing is to prevent the ECU from auto adjusting the timing to adjust to maintain the tick-over speed. If your engine is running, use a strobe and watch the timing dance around through the inspection hole at the top of the flywheel housing. VAG_COM or VCDS can switch to basic settings and lock the ecu to 0 advance from the distributor position. It is very hit and miss otherwise. (all hail to CRASHER for his help).
I also have a B5.5 which talks all sorts of things to the laptop, but the newer CAN bus system has been out about 4 years now and will soon be affordable, so if you replace your B4 with one you will have to upgrade to read it, your call

08-07-2008, 01:04 AM
Thanks for this info - looks like it does actually give good info! One quick question, are you using the full blown VAG-COM or the freebie download version?


08-07-2008, 10:40 PM
The 2E engine ECU only has ten fault code possibilities but it is necessary when setting the ignition timing to put the ECU into Basic Adjustment mode 04 and this requires a registered copy of VAG COM and it is also useful for various other checks. On some earlier 2E Golf 3ís and Passatís I have found VAG-COM will not communicate with the engine ECU whilst the engine is running which can make setting them up a problem. When this happens, I have to get my old code reader out as this will communicate when the engine is running. Also, you car may have the earlier 2x2 plugs so you will need the adapter. Beware of buying very cheap cables on fleaBay, a lot of people have trouble with them Buy one from forum user Eshrules and then register the software online with Ross Tec for $99

lpg boy
08-07-2008, 10:49 PM
I started out buying the VAG_COM unit for serial port operation about two and a half or three years ago, there were no e-bay offerings in those days. It came from Gendan and the software was version 6.?? in those days. I don't know what shareware level is available, but I am running on 8.05 recently downloaded. I am not a computer buff or teckie, so rather than take a chance I paid for peace of mind. There is a vag-com section on this forum site and it is well worth reading the histories of problems, although a firm recognised by this forum is Eshrules as a supplier of this type of equipment I believe.
Both Gendan and VAG COM give fast response if you are a registered user of the genuine equipment, don't know about others.
I did try and be clever and go from my older key-com to latest CAN BUS type by working through a part exchange deal with vcds direct not available in U.K. it was not as cheap as anticipated once postage had been added and then about 3 weeks later I got a £34 vat bill and a sodding handling charge of £6. Be warned if buying abroad!
But I can now read the latest vw group cars no matter which I replace my B4 with 221000 miles on the clock
good luck

lpg boy
08-07-2008, 10:59 PM
My passat is the same age as yours and it plugged in to the left of the steering wheel just above the height adjuster behind a speaker looking cover. if the connector is not there it may be a 2 plug type that crasher is on about. mine works with the engine running but is fully registered
and genuine.