trulytex

1990 Vert - My SIR light and seat belt light are on and my GM dealer pulled the code #26 - RF Wheel Sensor. I am trying to clear the code. I have the FSM and it tells me to ground terminal K - 3 Sec on, 3 Sec off then back on. But ground to what?

gw962

I think there is a write up on how to do this with a light switch wired into your jumper wire, which should give you more accuracy. From what I've read, there isn't much margin for error on the 3 second on-off.
As for a ground, I used a long wire with an alligator clip and attached it to the seat frame.
I need to pick up a switch though as I'm not quick enough to unhook and hook the clip in the prescribed time frame.
Mine is also a 90 showing the same fault code.

pipe

Mid America has a code clearing tool for $20 bucks It's a connector that goes to your ALDL connector with 2 wires coming out to a small momentary contact button. It's a cool little unit. But sometimes just clearing the code won't fix it. A code 26 is the right front frame sensor which is mounted on the frame rail very close to the firewall. DISCONNECT THE BATTERY! when doing any repairs on this system! You can unbolt the sensor from the frame and use a dremel or whatever and clean the area that the sensor sits on and the bottom of the sensor itself. Apply some Dielectric grease to the bottom of the sensor and bolt it back down. Then try to clear the code. Sometimes it will work but if not you will need to replace the frame sensor $60 bucks from GM GOOD LUCK WITH THE FIX Pipe

90TripleBlk

Do a search ... you will find lots of good information, especially in the TechTips section. I found two or three different methods to clear the code. All the same principle ... just different techiques. It took me twice as long to clear the codes as it did to fix the contact of the sensor to the frame. It may have been easier with the code clearing tool but it is just a simple on/off switch. You could make one very easily with wire, clips and a switch from Radio Shack.

gmboileau

I discovered that clearing the codes for the Sir system is tricky because you have to ground and unground the K terminal on the ALDL connector in a specific order for very specific times to clear the codes. It’s awkward to do this ground/unground process because of the location of the ALDL connector.

The clearing code sequence is:

1. Turn ignition off.
2. Ground ALDL terminal K-terminal A is a good ground
3. Turn ignition on.
4. Wait for fault codes to flash about 5 secs. When the codes begin flashing, unground terminal K for 3 secs +/_.5sec
5. Ground again for 3 secs. +/_ .5sec
6. Unground terminal K and wait 10 secs.
7. Ignition off



In order to make it easier to access the ALDL terminal K and to control the on off time I used a length of wire and a standard household light switch between the K terminal and ground. Just flicking the switch made it much easier to control the ground/unground sequence. Since the tolerance is only .5 sec either way a stopwatch is handy as well.

Cheers

Gary

Dads90

what is easier is to put the paper clip or small nail into Terminal K. Make a jumper cable with an alligator clip and clamp it to K. When its time to ground it after turning the key. Touch it on the lower seat frame. Then repeat as describe above.

Dads90

My bad, didn't read post number 2. Did you reseat the sensor ? Code may not clear if the contact is bad.

jfb

The outer shell of the cigarette lighter socket is also ground and is not painted like the seat frame is.

pipe

How did ya make out? Ya fix the problem yet? Pipe

The Beep

Couldn't pull a battery cable I suppose.