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View Full Version : Transfer case speed sensor woes.....HELP!



mrlegoman
06/17/2010, 08:48 AM
[edit] Problem fixed. Mechanic just forgot to plug in the OSS.

I'm at wits end.
I finally took my 99 VehiCross to a shop to get the transfer case worked on. I was expereiniinc really bad "tight corner braking" or torque bind as I call it. I was also getting a rear speed senor TOD error light.
I had bought a used (only 8000 miles, $250) transfer case from a salvage yard and had the shop swap the whole thing out.
I got a call today and they said they are still receiving the TOD rear speed sensor error and want to replace it for $360. What are the chances that BOTH rear speed sensors are bad? I want to think that something else is going on, but not sure where to look. Any suggestions before I blow $360???

VX KAT
06/17/2010, 09:39 AM
Would a non-OEM, but "LKQ" work for $80? Doesn't mention TOD though.

http://cgi.ebay.com/ebaymotors/99-00-01-Isuzu-Vehicross-Toyota-4Runner-Speed-Sensor-_W0QQcmdZViewItemQQhashZitem51935b2d81QQitemZ35036 4577153QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccesso ries#ht_3852wt_1377

mrlegoman
06/17/2010, 10:32 AM
Thanks for the link, but this is the TOD speed sensor.

front - 357(A) - Part #8-97181-686-0
rear - 357(B) - Part #8-97181-685-0

See if this works:

http://www.myisuzuparts.com/2001/756/2/2-61/showparts.html#flash
http://www.myisuzuparts.com/2001/821/2/2-61/showparts.html#flash
Go down and click on the 'eye' icon for 357(B) to highlight.

From isuzuparts.com
Item Number MSRP Core Price Price
8972516850 $409.17 $0.00 $322.76

I find it improbably that I'm getting the same code error with two different transfer cases (and thus two different sensors). I'd like to think there is another problem somewhere, but need some advice on where to look.

Triathlete
06/17/2010, 01:09 PM
Have you checked the wiring harness and plug going into the Tcase? Be sure to remove the plug and check the pins inside. If they look good give it a good cleaning with some electronics cleaner and follow the wiring back and check for chaffing or broken wires. Do the same at the TOD computer. As you said it sounds unlikely that two tcases would have the same problem. Plugs, wiring, and the computer are the incommon things.

mrlegoman
06/17/2010, 06:31 PM
Update:
I stopped by and talked to the tech to get some more info. He said that there was issues with the speedometer not reading anything and during a test drive, the transmission would not shift.......
So I asked him to show me which speed sensor he was refering to and he showed me the speedometer speed sensor. Not the transfer case TOD speed sensors.
That "LKQ" on ebay does not look like correct.

Isuzu part number match's Acura SLX or Honda Passport part number?! Same part?
http://www.hondapartsnow.com/transmission_automatic/atm19~1994~honda~passport~4dr_ex_4x4_v6~4at~ka~spe edometer~driven~gear.html

Ldub
06/17/2010, 07:34 PM
Isuzu part number match's Acura SLX or Honda Passport part number?! Same part?
http://www.hondapartsnow.com/transmission_automatic/atm19~1994~honda~passport~4dr_ex_4x4_v6~4at~ka~spe edometer~driven~gear.html

IIRC, one of those vehicles is a re-badged Rodeo (Passport) & the other is a re-badged Trooper (SLX)

mrlegoman
06/17/2010, 07:51 PM
IIRC, one of those vehicles is a re-badged Rodeo (Passport) & the other is a re-badged Trooper (SLX)

thumbs-up
Good stuff.

mrlegoman
06/18/2010, 10:42 AM
Update: Stopped by again to discuss the fact the speed sensor was working on the old transfer case and I was having issues with needing to buy a new one because now of a sudden it stopped working. He told me it was throwing a P0722 error code. Which I just looked up:

Output Shaft Sensor Circuit No Signal
(DTC P0722 Transmission Output Speed Sensor (OSS) Low Input) 7A1-48

I'm beginning to think he simply forgot to plug in the OSS as shown on page 7A-44. I think this is the sensor from the ebay link above. I couldn't find it on any of the schematics.

mrlegoman
06/18/2010, 01:21 PM
Update: Lots of lulz. He just forgot to plug in the OSS after installing the transfer case. Everything is good to go!

circmand
06/18/2010, 01:59 PM
now is the time to find a new shop befre you need it. any have qualified mechanic would double check connections before even saying anything let alone try to get you for more repair work. I would just this guy either unqualified or untrustworthy.

mrlegoman
06/28/2010, 06:11 AM
Update: Even more great news. The speedo quit working on me last week. I took it back in and they said the VSS was bad. I ordered a new VSS for $190, got it in today and 'oops' it still doesn't work. (I'm going to ask whether or not he took a volt meter to the VSS or just 'assumed') Turns out the speedo gear inside the transfer case is stripped out. Is this even replaceable without having to take the whole transfer case apart?
I would love to find another shop, but in our town, this is the only shop I've found in the last year within a 1.5 hour drive that will work on Isuzu's.

[edit] I re-read DTC P0502 VSS Circuit Low Input. If the tech followed this, then the stripped gear would have given him no signal. So I guess it would be plausible to assume a bad VSS.