Hi Bill,
Further wiring checks indicate that everything is intact. My mechanic suggested that I install the new sensor, new head unit and drive it for an hour or so to see if it would "learn" how to read and present the correct temp.
After about 35 min of temp running up and down between 80 and 36, the temp began to read in a reasonable range and after about an hour, it stabilized in a narrow range near the actual outside air temp.

Is this normal? Is there a learning circuit in the HVAC head unit?
Thanks.

 

The ONLY modules that require SYNC or LEARNING are the BCM/PCM and the Airbag Sensor module SDM

All other modules are or should be plug and play.


BC

 

thanks bill for this great info
shell

 

I think this will help many others so im bringing it to life...

 

Does anyone know which ground the SWPS in connected to?

Thanks!

 

It does not connect to any ground. Its a discrete circuit that connects directly to the EBTCM. The EBTCM connects to G101 and G104. what DTCs are you seeing whe its having issues?

BC

 

Hi Bill, it has been awhile. I hope all is well up north! Brian, aka cobra4b, and I replace my SWPS about two years ago and for a while everything was fine. However, for the last few months I have been getting "Service traction control" and "Service active handling" on my DIC almost every time I take my Vette out. When I look at the codes I get a C1287H Steering Sensor Rate Malfunction code so it appears to me that the SWPS is not broken but having some kind of power issue but as always I would appreciate your insight!!

Mark

 

This information is huge Bill. A big thank you coming your way! Last year I had just purchased my first 'vette. '04 c5 z06. I washed it under the hood and all kinds of fault codes blasted me, including reduced engine power. It barely ran and sounded horrible, for 2 days. I haven't let it get wet under there since. Now, with this valuable info, I am definately going to check these connections and reassemble using di-electric grease, first!!! Gettin' kinda grimy under there and I want to make her shine. You're the best!!! Thanks again.

 

IMPORTANT!!!!!!!! DO NOT USE Dielectric Grease!! Its more perfered and correct to sue this sort of stuff. You can get it on line or find something at any Marine / Boat store.



Dielectric grease can cause a bad connection! You can use it on the connector rubber seals to keep the moisture out but not on the connections.

BC

 

Hi Bill, any idea what is causing the problem three posts up?

Thanks!~
Mark

 

I just got this code yesterday C1287H Steering Sensor Rate Malfunction. I took apart the grounds under the hood as suggested and cleaned them, they were really clean compared to the pics posted, but I cleaned them anyway. Just went for a quick 15 min cruise and no codes, lets see what happens when I get a chance to drive her tomorrow.

Well it's back...took about 35 mins and it was back. Guess I may have to get a new sensor.

 

Hi

Thanks for the great information. I have the problem that the headlight don't pop up anymore. There is no noise and there was no noise before. The lights go on but the motor to pop up the lights doesn't make any sound. I already checked all fuses - none is borken - and I also replaced the relays No 44 (on the passenger side).

Do you have any idea why the headlights don't pop up anymore? There are no other electrical problems.

Thanks for your help.
Andreas

 

Wow, what a thread...

So after reading this whole thread and several others as well, is buying an alternator from Gene @ GMPartsHouse.com the best option? Are they rebuildable? by me or a shop?
$400+ for an alternator is steep, but if it is the best option, then so be it...

Wiring connections and grounds all check out ok.

Thanks again for all your assistance...

 

WHY do you think you need a new alternator???? Before you replace it tell me your issues.

BC

 

My friends 2001 model manual trans...

Intermittant charging system fault for about 2 months...

Two weeks ago checked wiring connections.

It went away. Reappeared yesterday while on the road... Battery went dead while driving.

Charge battery at home - starts fine. Today took altenator to AutoZone and it checked out OK - but does their test really work?

I'm going to be more thorough in checking all connections tomorrow.

As always, thanks for your help...

 

What is the battery terminal voltage with the car at idle?


Heres the generator schematic:



Run a temporary 10ga wire from the battery POSITIVE terminal to the BATT terminal on the back of the alternator. If the charging voltage increases and the FAULT message goes away, the circuit between the BATT & POS terminal is defective/corrupted

 

HI BILL! I think I really need your help. Several people have directed me to talk with you and said you were probably the man to most likely be able to help me. Here is my problem.
I have a 2000 C5 corvette. I just changed carpet, cluster, and seats. Old cluster was scratched. When I went to start the car it would just click and not start. Now, if I disconnect the battery for about 30 seconds the car will start right up. After about a minute there is a clicking noise coming from the BCM area and the heat and air control lights and interior lights will flash in tune with the clicking noise, but the car will run fine. If I turn the headlights on and turn the dash dimmer all the way down the clicking will stop and so will the flashing. But after I turn the car off, the car will NOT start back, and the security light in dash will flash. And the clicking noise coming from the bcm area will start again and interior lights will flash. When I try to start it again, either nothing will happen or the starter will bump and immediately stop but not enough to start it. Just a quick bump of the starter is all I get. The car will not restart until after I pull the battery cable back off and wait for atleast 30 seconds. I thought that it might be the cluster so I changed it back to my old cluster but still have the same results. I have load tested the battery and that was fine. I used the liquid electrical tape in the door wire jams like you have mentioned doing. I have taken the steering column back out and checked everything 3 times now. I have also checked in the connectors for any corrosion. Everything checks out. I have only had this car for 3 weeks, and I'm in way over my head on how to fix this. I can't find anyone who even wants to work on it. I cleared and reset the codes on the car. I got it started by disconnecting battery and hooking it back up and drove it for about 15 miles. This was the first time I got the Reduce Engine Power. I checked the codes when I got back home and these were the results...
PCM- no codes TCS- C1255H BCM- no comm SDM- U1000HC, U1064HC IPC- U1064H, U1176HC, U1160HC RADIO- U1096H, U1064H HVAC- no comm LDCM-U1064H RDCM-U1064H RFA- U1064H. Also when I load tested the battery these were the results...the battery was 12.51 with the key off and 14.10 with the car running. The computer ripple was 6.5mv. I really don't know what else to try. I'm beginning to think my car is possessed or something. I'm a girl and I pet my cars but this one is about to drive me crazy!!! Any help would be great. I tried to do alot of the things you have already listed but nothing seems to be helping. Thanks Jamie

 

Bill,
Did as you suggested.
It worked as you said.
My thinking is that the car starts fine every time, so it is likely the wire from the starter to the alternator rather than from the battery to the starter. Does this sound right?

So perhaps the fuseable link is bad?

We're going to pull the wires off the starter and do a continuity check to see if there is a problem there.

Thank you so much.

 

Today I put a brand new optima red top battery in the car today and nothing changed. Same symptoms. For the first time today when i was pulling into oreillys to get the new battery my message center read Low Voltage and a couple times now it has said reduce engine power. Do I have to buy a BCM from the dealer or can I buy one offline or from somewhere cheaper? Can I program it myself or do I have to take it to the dealer to have it programmed? I checked with the dealer here and they priced me $1900 alltogether. $1400 for the BCM and $500 for programming it. That seems a little high to me!

 

Bill Thankyou so much for the ground information . I have a 98 and its doing all of the same things. I do need some help with my Security light It will not go off. I have repalced the key and also tested the two wires off the switch the guy at the dealership told me the switch is fine. The light stayed on after all the crap went crazy with the gauges.I was going down the road and everything went crazy A/C stopped windows stopped, oil pres went to 0 temp went to red ABS light traction control light came on and info center said reduce power. After a mile or so evertything started working again but the Security light will not go off. im going to check the grounds if i can find them. any idea which ones i should start with, and do you think this will fix my Security light problem. Thanks for your Help