P1635 (Aux reference)
Anyone in the Cleveland/Akron, Ohio area that has a tuning business, please send me a PM. Also have a back up PCM that needs the crank learn performed, I think. When it was tried, got a crank sensor code & a coil missfire code immediately upon starting the engine. Am hoping to fix both issues.
SSpdDmon, thanks for the reply & please let me know what you think about the TPS code.
Comments from all are welcome & appreciated.
Thank-you
Anyway, my problems TPS, MAP,...etc. were related to a short somewhere in the EGR, MAP, AC wiring. The shop showed me that the internal PCM had these three on the same 5v/ground reference circuit. Because they are connected internally, connecting the alternate reference voltage directly to the sensor only worked momentarily until it too shorted out from becoming part of the shorted circuit. Once the MAP signal shorted, TPS issues started. Map sensor feed back was also causing the TPS out of range fault.
The MAF (low input) was happening because my idle was not charging the battery enough & the battery voltage would drop below 12v & set the check engine light. This, I found before going to the tuner. The book says that this shouldn't happen until voltage drops to 8v.. They couldn't explain why it was happening @ 11.99v, but, did increase my idle speed a little to get better charging. There were no MAF problems on the way home. Drove home w/ no MAP signal (because of the pending re-wire work) & it ran much better than when running w/MAP connected to the short.
The shop also got my second PCM working. The problem seemed also to be more related to the short than in the crank relearn. The tuner told me that he got no relearn codes & that the short was probably somehow related to the problem I had when first trying to use it. The short also fried the 5v. reference curcuit mentioned above when I had previously installed the second PCM.
So, all that remains is to re-wire the EGR, AC pressure switch, & MAP sensor from each sensor or switch directly to the PCM. Because the 5v. reference curcuit for these is fried inside both PCMs, an alternate source (probably a piggyback to other 5v. sources) will have to do.
Thanks again SSpdDmon.


