Date:         Fri, 16 Oct 2009 15:28:15 -0700
Reply-To:     neil n <musomuso@GMAIL.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         neil n <musomuso@GMAIL.COM>
Subject:      Jetta swap: Check Engine Light Install Electrical Questions
Content-Type: text/plain; charset=ISO-8859-1

Well I've been melting my head staring at diagrams/reading, and just
don't get it.

The new CEL works. Checking OBD, it blinks. Key at 15: CEL on. Engine
running: CEL off. CEL wire wasn't present at ECU connector from
factory. I re-routed an unused ECU wire (68/51 lilac/white) to CEL pin
(68/5) .   (*how I did it. )

Though it works I'm concerned because......

Ign. on or off, VOM see's 12.xx volts between B+ (30) and new wire
(ground) from ECU. But. No continuity is shown between new wire from
ECU and vehicle ground ign. on or off. I found this out by checking
things before running the new wire.

Should I test continuity between new wire "harness ground"? Still,
IIRC, all wiring harness grounds eventually connect to the frame.
Maybe the ECU ground is switched on/off by ECU, but then why do I see
12.xx volts with ign. off?

Positive connection to new CEL light is wired to 15. Is this correct?

I appreciate any help. The light works, but I'm concerned I might fry
the ECU over the long haul due to a minute wiring flaw. The ground
weirdness and lack of instrument cluster wiring detail (maybe an
electrical component crucial to proper operation of new CEL is
missing?) are prompting me to triple check my work.


Neil.


* Located ECU wire 68/51 in Jetta diagram. Physically confirmed pin
location at ECU connector. Grounded other end of wire to frame and
checked continuity. I didn't check to see if it spliced off anywhere
to +  within the Jetta harness as this wasn't shown in the diagram. I
have no idea what this wire was for, but AFAIK, it connected to the
Jetta instrument cluster which I'm not using.

--
Neil Nicholson '81 VanaJetta 2.0 "Jaco"

http://tubaneil.googlepages.com/

http://groups.google.com/group/vanagons-with-vw-inline-4-cylinder-gas-engines