New member,asr problem.high idle

[billybob93]

First I want to thank-you for letting me post my problems here on CM.I have a 93 LT1
(black rose) P-series. I first had a ses light, pulled a code 43 (knock sensors)!! When I
got in the car to go to Auto Zone to get the sensors. The service asr light came on and
(the car was warm up already) the idle shot up to 1800 rpms,and stay there!!! I change the K.S.,both of them thinking that was the problem. Clearred the codes. Started the car everything ok, until I turn the car off,and started again. ASR light back on!!! No codes this time. When the car sits for 7-8 hrs, it runs perfectly. I already change ICV, check the ground, battery is brand new(bosch), Pulled the codes on the CCM very erracttic,I was told this common when the asr light comes on(No communication from ECM).I have FSM I have read it ,problem could be 1 in 100 things. Also, a day or two before this all happen, I had a new set a tires put on (Firestone wide-oval Z-rated) I read that if you put wrong size tires on this could effect the wheel speed sensors,causing the asr light to come on. But I put the orginal sizes on! I was hopeling this happen to someone else,It starting to drive right up
the wall!!! Like I said it only happen after the car warms-up. Please HELP!!! I have
postted this on another forum NO HELP,no real answers THANKS

[c4c5specialist]

HI there,
Please POST CODES FROM CCM>
Theory is nothing compared to factual codes.
Second, if you have no communications from the PCM, that may be your issue.
When this happens, does any of your gauges stop working?
Any lights come on the dash??
Allthebest, c4c5

[billybob93]

Yes, my security light blinks three times, mph goes to 0 and doesn't registor any miles
on odometer. The codes I got from the CCM were mod.1 c41/ H41 ERR. on another mod.
(remember reading in FSM no comm ECM) mod 9 H72. I want you for a quick responce. I
was ready to take it to a dealer here in york PA. AT $100.00 just to get it in the shop
I like to fix it myself

[billybob93]

sorry for that last post , that should read thank-you for the quick response. Two other
thing,when this happens the engine will miss every now or then at 2500 or higher rpms.
Also it's a 6-speed. THANKS

[c4c5specialist]

HI there,
Based on the information, it sounds like you have one of 2 things.
ECM or CCM is dropping out communications.
Now, unfortunately, there is no accurate information to diagnose a dropout in the communications line, other than the symptoms you have.
Based on the ASR information, I would be leaning towards the ECM, because the ASR has seen a problem.
CCM shouldnt normally affect the ASR system.
Any other information from you may be helpful.
Allthebest, c4c5

[billybob93]

Maybe this will help,I know when this problem is going to happen before I crank the motor over. With the ingition in the on position, one of the coolant fans comes on,then the asr light, then the SES light,but only get code 12.