95 AAZ Passat issues

[patracy]

Here's a dandy issue I've had.  I was heading home and had to rev high to gain speed up the hill.  I revved it to redline.  Then it bogged and died.  Fearing the worse I drug it home only to find out I had no power to the IP.  So I hot wired it to a keyed +12V lead under the dash for the mean time.  Any idea what would have caused the power lead to the IP to loose power?  I've also noticed the fog lights no longer work. 

Everything else works fine on the car though.  Windows, locks, AC, radio, turn signals, exc.

[Vincent Waldon]

The IP is powered thru the Electronic Control Module... biggest black brick on the fuse panel on Jettas/Golfs... can't say for sure on the Passat chassis.

The line is unfused... so the most likely candidate is the module itself, or the wiring therein.

Do the glow plugs appear to be working OK??  They are also controlled by the ECM.

[Henchman]

Unless the 95 was different from the 93, I don't believe it even has an ECM. IIRC The shut off is controlled by the glow plug relay, which is controlled by the ignition switch.  I have had problems with Passat ignition switches where I have to push the key in and hold the plug on the back. So work forwards from the switch, to the relay, to the pump.

Ian

[Vincent Waldon]

Here's my understanding of the terminology:

ECM = electronic control module = analog circuit module that controls the glow plug relay, fast idle, EGR (if equipped) and supplies power to the AAZ's IP

Looks like this on a A3 Golf relay panel:



Not the same as the ECU... Engine Control Module... digital computer that controls a TDI's IP.

[patracy]

Is the part number 05-3402-30 ?  Or does anyone know where I can get one?  Or any means to test it?

[Henchman]

I get what you're saying.  Just compared to a b3/b4 passat AAZ, the Mk3 AAZ is Big Blue.  None of that voodoo magic 136 business!

As for the relay, it's easy enough to check.  Relay 103 is compatible if IIRC.

Ian

Here's my understanding of the terminology:

ECM = electronic control module = analog circuit module that controls the glow plug relay, fast idle, EGR (if equipped) and supplies power to the AAZ's IP

Looks like this on a A3 Golf relay panel:



Not the same as the ECU... Engine Control Module... digital computer that controls a TDI's IP.

[vanbcguy]

For what it's worth, the pump solenoid wire on my '94 AAZ Jetta is DEFINITELY fused.  The car has all the same "stuff" as the AAZ Passat would have.

How do I know it's fused?  I shorted it while the car was running.  No start after that.  Found a fuse labeled "Engine Management" or something like that, clearly blown.  Replaced, no issues.

[Vincent Waldon]

Found a fuse labeled "Engine Management" or something like that, clearly blown.  Replaced, no issues.

By george that rings a bell...some folks remove the Engine Management fuse as an anti-theft device... so stands to reason that it would control the ECM and thus power to the IP.

Good catch!

Vince