DTC P1361 and IAC testing
Dhood
11-25-2007, 02:11 PM
Been having this code pop up now and again and recently running rough with SES light on under cold damp startup conditions. Sometimes an immediate restart will solve the problem. Replaced spark plugs and wires and checked coils as OK. I have a 94 TS 3.8 with 115k miles. Previously replaced the IAC and CPS about 7 years ago so now thinking its the same thing. Wanted to rule out the IAC and connector so tested ckts 423 and 424 at the PCM with an ohm meter and came up with 20 k ohms. This is outside the "well under 200 ohms" specified in the GM workshop manual so I took the IAC out and measured just the two pins for those circuits. Same reading. Read the resistance on a "known bad" IAC, same thing. So off to Autozone to get my free replacement and find out nowadays, they have a multitester that can check the conditon of the IAC. Both boards passed after five tests each.
So my questions is this, if the manual is correct and there is a much higher resistance in the IAC itself, is there a mistake in the manual? I used two different ohm meters and came up with matching results. The IAC female connectors for these two pins were flattened out so I reshaped them and retested the connection thru the firewall connector. The PCM grounds are good and clean too. Any other ideas for the intermittent DTC or are we back to testing the CPS? Thanks for all the help in this forum, great place to learn and share ideas.
So my questions is this, if the manual is correct and there is a much higher resistance in the IAC itself, is there a mistake in the manual? I used two different ohm meters and came up with matching results. The IAC female connectors for these two pins were flattened out so I reshaped them and retested the connection thru the firewall connector. The PCM grounds are good and clean too. Any other ideas for the intermittent DTC or are we back to testing the CPS? Thanks for all the help in this forum, great place to learn and share ideas.
maxwedge
11-25-2007, 02:34 PM
1361 is the est circuit not toggling according to my info?
Dhood
11-25-2007, 04:26 PM
1361 is the est circuit not toggling according to my info?
Yup. "Timing signal not switching after enable." Ignition remains on module timing.
Yup. "Timing signal not switching after enable." Ignition remains on module timing.
maxwedge
11-25-2007, 06:43 PM
Check this link, this is a pcm, icm issue as well as bad in puts from the crank sensor or cps. http://service.gm.com/gmspo/mode6/pdf/1995/95c38k_F__aE.pdf
Automotive Network, Inc., Copyright ©2025