

| Subject: | Jetta swap: Check Engine Light Install Electrical Questions |
| From: | neil n |
| Date: | Fri, 16 Oct 2009 15:28:15 -0700 |
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
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