TOD - Front sensor?

Hello VXers! My issue is with the TOD system. I hope someone has some helpful into for me. Some info and some questions below.

The otherday the TOD lights went full on front (and rear). I could feel a bind or dragging when turning the wheels and moving forward or backward.... sharp turns etc. It might have pulled out of it the otherday on the way to work, but if it did, it started again immediately. I would be willing to say that it never stopped. The CHECK light is also blinking.

I pulled the codes using the light diagnostics by shorting pin number 8 on the diagnostic connector. I got codes:

16 and 21

These are the front speed sensor, and the throttle position sensor respectively.

I don't think the issue is with the TPS, although it is a TOD sensor of sorts so it could be. I am leaning to the front axle sensor that is on the transfer case.

When I hit up isuzuparts.com I run into several (4)"speed sensors"...

Number one is listed as a Powertrain part and the others are listed as Anti-Lock brake parts. Two of them look to be exactely the same.. (could be 'A' and 'B'...?) When I talk to the dealer, they sound like they are looking in the right place, but they quote me what seems like it could be a wheel/hub speed, anti-lock brake sensor from the descriptions below.

(1) VEHICLE speed sensor, Vehicross 99-01 $180.88 $0.00 $144.70
Electrical - Powertrain control - Vehicle speed sensor


(2) FRONT speed sensor, Vehicross, Right 99-01 $350.94 $0.00 $280.75
Brakes - Anti-lock brakes - Front speed sensor


(3) FRONT speed sensor, Vehicross, Left 99-01 $350.94 $0.00 $280.75
Brakes - Anti-lock brakes - Front speed sensor


(4) REAR speed sensor, Vehicross 99-01 $446.25 $0.00 $357.00
Brakes - Anti-lock brakes - Rear speed sensor

When I call dealers, they wittle down the into the parts catalog and quote me an 'A' and a 'B' sensor. I think, based on location, that the one I need is the 'B' senosr (if I indeed need it at all), but it seems that the sensor is labeled as being for "anti-lock" brakes... I am a bit nervous in ordering due to the price differentials, and simply because I can't seem to find a parts guy that knows what is what. (or can really make me confident that he knows what he is sending me)

So I am thinking I will just replace the front axle sensor that is on the transfer case. I am hundreds of miles from a dealer, and don't have a reader to do the proper test to make sure, but the flow chart on the fault code leads pretty clearly to the sensor.. or a connection concerning the front speed sensor... etc.

Does anyone have an idea what the part number for that sensor might be? I just would really hate to get the wrong thing... I get impatient with parts guys, as I am a parts guy myself. Dealer parts guys (some anyway) might as well be selling parts for horse carriages for all they know... sorry.. starting to rant... better end it here! :p

Thanks for any info that anyone has! Keep on VXin'!

fourteener

I had the front speed sensor code come up on me after a drive in the rain. It vanished when dry. When the code sets, the transfer case locks the front and rear wheels together, that funny feeling is tires scrubbing.

It turned out to just be a wet connector. The sensor itself is very durable.

John C.

Hey Hotsauce, thanks for the reply.

I am going to be pulling the connector apart tomorrow, inspecting, cleaning, etc. I am with you on the connector or connection being an issue. Our streets get a lot of magnesium chloride put on them in the winter. It could easilly be short related. I will be sure to get back here either way to get the issue resolved. I am just getting my ducks in a row so to speak with the sensor.

It is certainly doing what you and others have described as far as the lock up.... only 16,800 miles too. I love it no matter what. Simple fix... just follow the procedure ya know? :)

Thanks again, it gives me a couple hundred dollars worth of hope! :cool:

fourteener

I have the same thing going on with my 01. Is there any excessive noise comin from the enigine (at idle or while drivin)? like a squeek coming from the drive belt area?

If so you could have a bad alternator

my problems first started when it would rain or if i had snow packed in between the wheels the TOD light would begin to flash. then when dry or if i kicked out the snow it would work again no problem. actually i though i had a short some where because my TOD, radio, and A/C would peariodically short out. When i took it to the dealership they said if the atlernator is not charging the car enough (like mine was)then the car will first cut the power for the TOD, then the A/C, radio and so forth. Poor alternator probally from all the "hossin" i do in the gravel pits :bgwo: Anywho if the TOD cuts in and out it might be a alternator problem. Good Luck!

Finnaly got around to pulling connectors under the VX to get to the bottom of the TOD issue. I began with the one on top of the transfer case. With 16,800 miles on the VX, the connector came apart clean as a bean and went together with an appropriate snap.

I moved from connector to connector under the VX looking for anything that could be an issue. I came across a longer connector closer to the front of the vehicle, but very accessible. It was typical Delphi style weather pack double/triple layer seal. The connector had some of the orange seal exposed. Hmmm.

I took it apart and the connector was again.... so clean that I wanted to cry. I could smell clean. Made me proud. :p

The fit concerned me slightly so when I put it back together I made sure that the connection was solid. The seal doesn't want to go back in very well, but they are suppose to be weather tight (or almost) so I worked it a bit.

When I heard the snap, I knew that the connection was good. The orange of the seal still wanted to bulge out ever so slightly, but the connection was measures above the condition it was in.

I drove it around the driveway and TOD wasn't angry (blinking). It had the first two lights of TOD on. Those are usually never on. I just assumed that it was still intermittantly messed up as it was doing the same thing between "lock ups".

Today....

I decided to clear the codes as the light wasn't flashing. I needed it to flash for the verification process with my technician. I called to see what type of time frame they had...

"Clear those codes man"... "Give it a try."

I jumped number 8 on the diagnostic connector, put the transfer case in neutral with the E-brake on, turned the key to the on position and hit the brake 5 times rapidly.

Codes clear. Test drove. Problem gone.

Not only is the problem gone, but my VX is actually operating the way it should for the first time EVER (I think anyway). TOD never had much to say before today... except for the angy lock-ups.

I mean... it lit up sometimes.. but not often. Now on the otherhand, TOD is operational. I can tell that it is operating like it was designed. It is certainly more sensitive than it was before. It is almost like it WANTS and ENJOYS working now... before it just seemed not to do much at all... sluggish.. late...gimmicky I took the car out and drove in figure 8's very carefully, then at full lock pretty slowly. No issues. I drove pretty quickly backwards, and turned at various speds. I basically followed the flow chart and the drivability test as described in the workshop manual.

Did I say no issues? ! :cool:

WOW

I am super pleased. I cross my fingers and hope for the best, but for some reason I don't think I will be seeing those codes again.

I thought I would get back to close the issue. I can't stand reading about issues only to never hear from the poster again. I will certainly pop back in if it comes up again!

Thanks VX.info for all the help you all offer to the VX community. This includes all the peeps that make up the community.

fourteener & TOD

Thanks for the indepth follow up report on your situation and conclusion. Good to hear that you managed to elliminate any possibilities of issues with the TOD and successfully resolved it.

I, too, had a TOD sensor issue which turned out to be a defective sensor located on the transmission case. Turned out to be either the rear sensor that was the culprit but could not tell which of the two sensors it was as they both were located in the same area. Also, when ordering from St. Charles, they were identically the same sensor visually except for one wire which was a different color on both. Turns out that the color differentiation just determined which harness and location point the sensor was designated for. Otherwise, both rear and front sensors were performed and looked the same. Never had an issue after the replacement. Saved a lot of cash since the dealer wanted a chunk just to order the part not to mention the outrageuos quote of installation which took me about 5 minutes to do.

Good job.

Well, I overreacted as the code came back. I took it to a local shop (50 miles) and he did some checking and cleared the codes and drove it (I spun the wheels and gave it a good check).

$250 for nothing.

I am going to fix this thing myself if I have to replace all 12 sensors and everything else involved. (although my bank account will struggle with one sensor I am sure)

Gonna call St. Charles tomorrow and order a front wheel sensor on the transfer case if they think it is even remotely a good idea. Anyone replaced one of these before? It looks easy enough, but I am not sure. (sorry ron, missed that you have done it. easy enough?)

I will not be defeated!

:cool:

Try a freebie first and pull the front abs sensors. There was a post about them collecting rust since they're magnetic. Clean 'em off and reinstall. All that will cost is your labor.

Might as well check all the sensors' wiring as far as you can trace it and check the tps connection too.

Also check the main wire loom behind the headlight for chafing on the radiator core support, it has been reported as a source of strange behavior.

I don't get the part about it going away for a while then coming back...