I have been trying to get all of the kinks worked out on my truck and I can't seem to get this one. My CEL flashes codes #11 and #12 when I do the key trick. #12 is because the PCM has been disconnected from the battery w/in the last 50 cycles which I already know. The problem is code #11 - "No distributor reference signal detected during engine cranking. Check circuit between the distributor and the PCM."

Has anybody had this same issue, and if so, what do I need to do to fix it? Everything appears to be ok under the hood so I'm thinking the culpret may be something hidden. The truck seems to keep wanting to pulse under normal throttle and keeps trying to decide which gear and RPM it wants to use when I push it a little harder. I'm hoping that whatever is throwing this code is causing this irritating condition. Any help on this will be greatly appreciated.

 

Not 100% sure but I'll take a stab at it ;-). CEL #11 usually set off a P1391/P1398 code in scan tools. These two codes reflect on: Intermittent Loss of Compression or Cranking Pressure/A Misfire Adapt Numeral is at it's limits. This first one with Compression issues is monitored with engine running and when the failure counter reaches 96 for two consecutive trips. It could be caused by several things:

1. Open or shorted 5 volt supply circuit
2. Open sensor ground
3. Open or shorted signal circuit
4. Excessive crankshaft sensor clearance
5. Excessive camshaft sensor rotating component
6. Damaged crankshaft sensor rotating component
7. Damaged camshaft sensor rotating component
8. Failed Sensor
9. Failed PCM

I've compiled some photos for ya as well:

read and print them all out and follow them in order...lemme know how it goes ;-)

http://i116.photobucket.com/albums/o38/CKovacs244/1.jpg

http://i116.photobucket.com/albums/o38/CKovacs244/2.gif

http://i116.photobucket.com/albums/o38/CKovacs244/3.jpg

http://i116.photobucket.com/albums/o38/CKovacs244/4.jpg

http://i116.photobucket.com/albums/o38/CKovacs244/5.jpg

http://i116.photobucket.com/albums/o38/CKovacs244/6.jpg

http://i116.photobucket.com/albums/o38/CKovacs244/7.jpg

 

it proubly wouldnt be the pcm tho because pcms rarley go out it will usually be something like a ground came loose or to much resistance in a wire or an open in the circut all your pcm does is controll the grounds to all the circuts

 

Thank you greatly on the in-depth information! I will work on this today. I'll post how this goes once I've finished. I hope this fixes it and eliminates all of the pulsing issues.