No more speedometer

[JiPi]

Hello,
A friend has a '98 GTS. His speedometer is not working anymore and he got a check engine light. He went to a mechanic who connected his scan tool to the car, but said that he couldn't get any information from the tranny. He has an appointment next Tuesday and has to leave the car for two days to track down the problem. He already checked the fuses, the wiring harness and all the connectors coming from the transmission but with no success.

I don't know if it's related, but his white reverse lights are not working either.
Do you have any idea regarding these two problems?

He doesn't have a powertrain diagnostic procedures manual for his '98, but I have one for my '96RT. Is the repairing procedure the same?
Thanks in advance for your help.

 

[V10SpeedLuvr]

I would say its the output speed sensor, but a scanner should easily pick up that code.

 

[ViperJohn]

The tranny is the same, but the cars have different PCM's so I am not positive how that will affect troubleshooting.

Regarding the reverse light: Is it possible the skip shift and reverse lock out plugs are swapped? They are the same connector and have been put in wrong when replacing or working on a tranny before.

And I agree with Chad about the speed sensor, sometimes they quite working but don't throw a code.

Hopefully Tator will see this on Monday and chime in. He should be able to shed more light on this subject.

 

[Tom F&L GoR]

The speedo is powered by the PCM, while the BU light goes through a fuse. The only thing in common is connector C330, which is listed as being on the left frame rail and black in color. Unfortunately it is one of the few that the sevice manual does not show a location picture for.

It is a ten wire connector with the following colored wires in/out:

DB/GY
GY/OR
VT/BK
WT
DB/GY
LB/BK
VT/WT
BK/LB
WT/OR
one location left empty.

If you have the service manual, look at page 8W-80-41.

 

[JiPi]

Yes, he has a service manual. I will tell him to have a look at this section.
Thanks for the input.

 

[HARDVIPER]

Hey this could be a blessing no more miles on your baby!

 

[95Viper]

I have an extra speed sensor for a 95 if he needs one. I bought it thinking it was my speedometer problem when it turned out to be my PCM.

 

[JiPi]

Thanks 95Viper but I heard the dealer already order the speed sensor. Hope that is the problem and not something else.