: TPS - Problems

12-06-03, 12:19 PM
OK well here's the deal.

I recently bought a 93 Cadillac STS. It has some minor issues that I need to resolve.

The shocks are blown $$$$$ - picked up a passive replacement set
The engine idles rough - picked up wires, plugs, TB cleaner, etc
The engine occansionally stalls.

The previous owner believed the rough idle to come from a malfunctioning TPS and removed the TPS to replace it. Problem was he bought the wrong part. They reinstalled the TPS, but from what the PCM is telling me they did not teach the PCM the new idle.

PCM Data: PD01

Engine off

- 6.6 when closed
- 80.4 WOT

Engine on

- ~2.0-3.3 closed
- 80.4 WOT

I also get codes:

P070 - Intermitent TPS Voltage
P030 - ISC Out of Range

Now what all that tells me is that the TPS is not adjusted properly, (should read 0.0 when closed 100.0 WOT) correct? The PCM was not taught the new idle. The ISC is having problems controlling the idle because the TPS is sending voltages that tell the PCM I have my foot on the gas.

I have bought a new TPS (just in case the old one is bad) but I have only been able to find the TPS Learn Procedure for the 4.9L engine not the Northstar 4.6L.

Could someone please tell me if this procedure works for the 4.6 or if there is a different procedure for the 4.6L engine. As well any insight into the problem would be greatly appreciated.



Aurora By Olds
12-07-03, 02:31 AM
My complete manual is out in the garage, but If I remember correctly, this was the procedure for idle relearn:
Start engine, and let idle until operating temperature is reached (180degrees)
Idle engine for an additional 5 minutes.
quickly rev engine over 1500 rpms and let idle again.
Place gearshifter into drive (D) range and let idle until MIL goes out. (shouldbe less than one minute)
and voila, this should do it. It worked for me once.
Also, there is a TPS relearn as well, that should be performed before the idle relearn, if I remember correctly.
After everything is reconnected, turn key to the "on" position, and then turn it back off. Wait at least 30 seconds, and repeat. Do this a total of three times, and it will supposedly relearn the TPS.
I only have the preliminary Aurora service manual, so I cannot look up the codes to follow the flow chart, but if this doesnt help, you may want to look into a set of manuals, as you seem to be somewhat familiar with drivability and emissions systems.
They are certainly worth the money, 10 times over.

12-07-03, 09:05 AM
Thanks for the reply.

I will go and give it a try and see what it gets me.

As for the shop manual, I can't seem to find one. I asked the dealer (HAHAHA) they want $250. Can you say GET LOST.

Anyways if anyone could point me in the right directions for a shop manual I would greatly appreciate it.



El Dobro
12-07-03, 02:23 PM
You can get the original manuals from Helminc.com . You can also do a search on eBay. A heck of a lot cheaper there.

Aurora By Olds
12-07-03, 02:32 PM
You can get the original manuals from Helminc.com . You can also do a search on eBay. A heck of a lot cheaper there.Ditto. I bought mine new from Helm for about $115. Ive seen them go on Ebay after that for under $50.