P1635 (Aux reference)
10-30-2006, 11:53 AM
#1
P1635 (Aux reference) Wired 5v ref to MAP sensor from the Aux 5v reference port (#72 on Blue connector) because the MAP 5v reference stopped working. The MAP now works fine except the PCM keeps throwing this code. I think it's just telling me that this Aux reference is now being used because there is nothing wrong with the reference output. How can this be permanently cleared? It doesn't remain cleared after an OBDII sode delete. Thanks
10-30-2006, 12:16 PM
#2
TECH Addict
iTrader: (10)
Join Date: Jun 2004
Location: Commerce Twp, MI
Posts: 2,918
Likes: 0
Received 0 Likes
on
0 Posts
Anyone with some tuning software can turn it off under the DTC enablers. From the factory, it's set to throw a code after 2 trips. What else uses that pin or used to use that pin? Anyone know?
10-30-2006, 03:34 PM
#3
Originally Posted by SSpdDmon
Anyone with some tuning software can turn it off under the DTC enablers. From the factory, it's set to throw a code after 2 trips. What else uses that pin or used to use that pin? Anyone know?
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
10-30-2006, 05:25 PM
#4
TECH Addict
iTrader: (10)
Join Date: Jun 2004
Location: Commerce Twp, MI
Posts: 2,918
Likes: 0
Received 0 Likes
on
0 Posts
I'd set the TPS sensor based on how the write-ups suggest (ie - the bumpstop write-ups). Then, perform the TPS reset procedure. If it's still a problem, then you'll need some software to adjust the TPS tables (under Engine Diagnostics). Typically, the lower threshold of the TPS test is what people have to change because cam'd setups require a higher idle with 0% throttle.
10-31-2006, 06:20 PM
#5
A bit long 'cuz we found the gremlins Kinda fell into finding a local tuner who actually has been building race cars for 30 years. The shop has recently added street/track set ups & tuning to their services.
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.
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.
