So last night I decide to take the "garage queen" (only 19K on the car) for a drive & disaster! Driving perfectly fine, then all hell brakes loose!! I get the following warning on the DIC:

1. reduced engine power
2. service traction system
3. service active hdlg

*As a side note, I do not have wheel sensors in my current wheels.

I do have a scan unit & I get the following codes:

1. P1120 Throttle Position (TP) Sensor 1 Circuit
2. P1220 Throttle Position (TP) Sensor 2 Circuit
3. P1515 Control Module Throttle Actuator Position Performance
4. P1516 Throttle Actuator Control (TAC) Module Throttle Actuator Position Performance

Anyway I manage to limp the car home as it will not go over 2K! So this is were I am at, PLEASE help!!!

PS Oh yeah, to make the night better, when I get home wife tells me a/c is NOT working..... home a/c compressor motor is done....NOT my finest day.

 

You don't need a scan tool to pull the codes. Have you ever pulled them thorough the DIC?

http://www.google.com/url?sa=t&rct=j...OqDUpN0NsM2tmw

 

I just learned that....LOL. I just also happen to own a scan tool. In the future I will definitely do it through the DIC.

So far things (based on research I did this am) are pointing at the TAC (Throttle control module).

Do you by chance happen to know were it is located??

 

Attached to the PCM. This link will show the picture of it also.

http://forums.corvetteforum.com/c5-t...-location.html

 

Sorry for dupl post

 

Another dupl

 

Thanks for the info!!

 

Sounds like my car. Last week.
It's a 2 car epidemic.
Same warnings. Same slow crawl to my destination.
I only had the P1221 code in common though.
Mine is fine now, but I need to dig into it. It will fail again.

Ron

 

Ron,

I started mine earlier today (after I cleared the codes) & exactly the same!! It starts at 2K & stays there, regardless if you floor it. It won't go past 2K, like the throttle body is stuck in that position.

I am going to get a new to me (as I have NOT found a new one) TAC (throttle actuator control). They run about $220 used. Again, all my research points to this. I will let you know how it turns out.

The MOST upsetting thing is that I bought my car NEW & it sits in the garage most of the time, only has 19K. So for a part to go bad on a well cared & not abused (does not see rain, blah, blah, etc...) car is VERY frustrating!! Oh well.....

Mike

 

Early electronics left a lot to be desired for sure. Especially a lot of the connectors. They are very poor quality.
Good luck! At least you have a hard failure. Not an intermittent.

Ron

 

3318C5
Did your problem end up being the TACM?
I have same 4 codes.

 

Big thanks to bill and dadaroo. <br/>I ended up finding the problem was mechanical and not necessarily electric. <br/>The throttle body shaft was broken in two. This allowed the tps voltage to not match motor control. Crazy. I pulled it apart and welded it up until I can find a new shaft. Even though throttle body is 100mm. It looks like the shaft is a stock part. Hopefully

 

I have a 98 Vette with 20,000 miles, and experienced a variety of similar problems. To name a few, Steering wheel locked up with dreaded remove key and wait 10 seconds Message. Fuel system cut-off allowing about 2 miles per hour top speed. headlight doors would not open until you twisted the switch at least twice. Driver's memory seat never found the correct position. I will make a long story short. I guessed after doing much reading that low battery voltage could be causing my problems. When the problems occurred the voltage reading was around 9.2 or 9.4 with the key turned to the on position, which was enough to start the car but I'm not sure it was enough to activate the necessary electronics to make the above items operate successfully. My solution, put a battery charger on the battery for a day and brought the Amp reading to 11.4 amps with the key in the on position. I have driven the car daily for about 3 weeks now and have not experienced any more of the above problems. Each time I start the car now I check the battery reading and it is between 11.2 or 11.4 volts. I also invested in an inexpensive trickle charger to maintain the battery during long idle periods. Hope this helps.

 

Where are you reading the voltage, on the DIC or at the battery?


A fully charged battery should be 12.6v or more.

It's not 12 volts it's 12.6 because each cell is 2.1 volts.

If the battery is

12.5 = 85% charged
12.4 = 65%
12.3 = 50%
12.2 = 35%
12.1 = drained

The starter will work with low voltage because it likes current. The electronics need the voltage. Low voltage makes the electronics do funky things.


Mr. Sam

 

I am reading the voltage on the DIC. Just to be clear I am not a mechanic. It became apparent that the Steering wheel lock and the Fuel cut off showed up when I would return from a trip and the Vette sat Idle for 2 or 3 weeks. I actually removed the battery from the car while I was charging it so I had to Re-Program the Key fobs when I put it back in. At present time the Memory seat works, Headlight doors require one turn of the switch to open and light and the steering wheel lock and fuel shut off have not returned. If The Wheel lock and fuel shut off problem return I would probably install the LMC5 Module available from Richard at Compliance parts (855-565-8388)

 

I highly recommend you just install the LMC5 and be done. Very inexpensive. I have info on that at home I can post if you like.

One should always be reading the voltage AT the battery also. That can tell you if the battery or the ignition electrical is affecting the voltage. Everything that is HOT in ON goes thru those switch contacts and they have a history of issues due to use. The DIC reads the voltage AFTER the switch.


Mr. Sam