While in the paint shop getting the front of my 99 painted, apparently the mechanic unhooked the battery (Clock's time was off). (They removed the front clip to strip). After getting the car back yesterday, I noticed that the alternator wasn't putting out enough voltage to the batt. (12.1 w/ air on , 13.3 w/ air off). This unit was charging before I sent car in. Also, I was getting no tire pressure readings while car was at a standstill but seemed to get them while moving. And to top it all off, now I can't program my key fobs to work.

Anyone have any idea as to if I can reset this system in any way? This is my 4th vette but all others were older (64-79) and we didn't have all of these computer probs back then .

I've always been my own wrench and have service manuals for this vehicle.

Any help or info will greatly appreciated!!

Woody (vetter79)

 

I'm sure my driver's handbook says that the tire pressures won't show until 15mph.

 

From what I was told, the Tire Pressure Monitoring system uses the ABS circuitry to send the signal back to the DIC and needs the wheels turning to induce the signal. I don't know about the other stuff but I would certainly let the shop know where you had the work done that you are having problems now that you didn't have prior to them having the car. Be sure and let us know how things worked out.

 

to rerpogram key fobs, if you have 2 do them both at the same time .
. Turn the ingnition key to the ON position
2. Clear any warning messages on the Driver Information Center (DIC) by pressing the RESET button.
3. Press the OPTIONS button on the DIC several times until the blank page is displayed, then press and hold the RESET button for two seconds.
4. When the message FOB TRAINING is displayed, push the RESET button once. The message HOLD LK+UNLK 1ST FOB will be displayed.

5. Press and hold the LOCK and UNLOCK buttons on the transmitter simultaneously for 15 seconds.

6. When a transmitter is learned, the DIC will display FOB LEARNED and then prompt you to learn the next transmitter.

7. Repeat steps 5 and 6 for each additional transmitter.

8. Remove the key from the ignition.

 

i would check to make sure all of the grounds are clean and tight in the front and check the codes you have. in general it seems like a bcm com problem or low battery problem. mine usually shows 14-14.3 volts while charging. maybe drops to 13 with a/c on.

 

Thanks for all the advise guy & gals - Fround the prob (after I found the alternator OK). Bad battery - Replaced and all is well now. Alt. shop said the they thought some vettes had some sort of sensing in htem that would stop the alternator from putting a full load into a batt. that was going down the tubes. Not sure about this but it worked for me. (was running about 11.4 volts on a batt. that should have been charged, so this guy was on to something!!

 

Close ... but no cigar ..... someone misinformed you ...

The Tire Pressure units in the tires have a small radio transmitter in them. They transmit 2 pieces of data ... the tire pressure, and the units unique serial number.

The radio transmissions are picked up by the RFA (Remote Function Actuator) which is a radio reciever that also picks up the transmissions from your key fobs. The data is then sent to the BCM from the RFA, and the BCM has the software that displays/alarms the tire pressure data.

When you move tires around on the car, and then go into TPMS "training" mode, the BCM displays a message to train the LF tire. The magnet you put near the tire stem wakes up the sensor and it transmits its serial number and tire pressure. The BCM then internally stores the information that that particular unit (serial number) is at the LF position. As you go round the car training the system, the BCM is simply "learning" the serial numbers of the sensors, and where they are located.

When the wheels stop turning, after a few minutes, the sensors go to "sleep" to conserve their internal batteries. When the wheels start turning again, the sensors wake up and start transmitting their serial number and pressure again. I believe they transmit several times a minute until the car has been stopped for a number of minutes (like 15 to 20).