Q: I have been chasing a canister purge solinoid code (26) for a while. I had a bad Solinoid and some bad hoses -- all were leaking pretty badly. Canister is okay. I checked my wiring and PCM -- all good. But after ~30 seconds of running, the code reappears and the SES comes on. Just out of dumb luck, I turned the A/C on. In about 5 seconds the SES went out. I have found that if I leave the A/C on, I get no code. Any explainations for that one?
The AC kicks the idle up a little bit. Maybe the increased idle speed prevents whatever condition sets the code? -DanD
I believe the A/C clutch driver is the same "quad driver" that can cause EGR/canister purge solenoid/etc. SES codes. It's conceivable that for example the canister purge solenoid is just barely out of spec and the extra current draw of engaging the A/C masks this. Tim.
Well, there should be nothing (EGR, Purge solinoid, etc) out of spec, because I had to replace them all already. I'm pretty sure the problem is in the PCM. I went and tried a test PCM and the code stayed away with and without the a/c on. Previously, before replacing the purge solinoid, both would code 26. Tim, I think you are on to something. If there is an internal problem with the "quad drive", this could explain it. I only had limited time to test it, but I'm pretty sure the other PCM will be the cure. Thanks!
but I'm pretty sure the other PCM will be the cure Don't neglect checking the wiring harnesses and grounding (battery to frame and PCM to frame in particular). It'd be awful to buy a new PCM when all you really needed was to clean up a few ground connections. Tim.
Thanks for the info. I go down the road of bad grounds at my "real job" quite a bit. It will cause some strange problems. The PCM actually cost me a whole $28.00 plus shipping on Ebay.
