90 XJ AT shifting / TPS problem
03-26-2006, 12:29 PM
#31
Guest
Posts: n/a
Re: 90 XJ AT shifting / TPS problem
JRK58@MSN.COM wrote:
>
> I pulled the fuse from the TCU and it shifts fine manually, also took
> some readings at the TCU and they are way off. I guess a bad TCU? The
> link that Bill gave has some great info on checking the TCU but I was
> looking at it backwards and thought it was 180 out. The guy also says
> at the end that if the readings are within spec the TCU is a
> transmission condemed unit, I'm thinking he meant out of spec.
Or he was meaning if it checked out ok, the tranny was condemned?
Do you have a transmitter on board by any chance? I know that a
transmitter can cause the TCU to have total brain farts if the wiring or
antenna are anywhere near it or it's harness.
On the 90, the ground still jumps out screaming at me....
I think I would run a dedicated ground jumper to the TCU just to see
what happens, same for your ground jumper idea on the TPS ground.
A lot of the computer grounds terminate on a bolt on or near the oil
dipstick. There will be a bunch of small black wires bolted on there.
That might be worth a clean too.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)
>
> I pulled the fuse from the TCU and it shifts fine manually, also took
> some readings at the TCU and they are way off. I guess a bad TCU? The
> link that Bill gave has some great info on checking the TCU but I was
> looking at it backwards and thought it was 180 out. The guy also says
> at the end that if the readings are within spec the TCU is a
> transmission condemed unit, I'm thinking he meant out of spec.
Or he was meaning if it checked out ok, the tranny was condemned?
Do you have a transmitter on board by any chance? I know that a
transmitter can cause the TCU to have total brain farts if the wiring or
antenna are anywhere near it or it's harness.
On the 90, the ground still jumps out screaming at me....
I think I would run a dedicated ground jumper to the TCU just to see
what happens, same for your ground jumper idea on the TPS ground.
A lot of the computer grounds terminate on a bolt on or near the oil
dipstick. There will be a bunch of small black wires bolted on there.
That might be worth a clean too.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)
04-25-2006, 07:35 AM
#35
Guest
Posts: n/a
Re: 90 XJ AT shifting / TPS problem
On Fri, 24 Mar 2006 19:17:49 -0800, L.W.(ßill the goat ----er) ------
III <----------@***.net> wrote:
> The Throttle Position Sensor is like a mechanical kick-down rod and
>lever,
Oh my god can you possibly be more wrong, goat----er?
--
Just your average Joe.
III <----------@***.net> wrote:
> The Throttle Position Sensor is like a mechanical kick-down rod and
>lever,
Oh my god can you possibly be more wrong, goat----er?
--
Just your average Joe.
04-25-2006, 07:35 AM
#36
Guest
Posts: n/a
Re: 90 XJ AT shifting / TPS problem
On Fri, 24 Mar 2006 19:17:49 -0800, L.W.(ßill the goat ----er) ------
III <----------@***.net> wrote:
> The Throttle Position Sensor is like a mechanical kick-down rod and
>lever,
Oh my god can you possibly be more wrong, goat----er?
--
Just your average Joe.
III <----------@***.net> wrote:
> The Throttle Position Sensor is like a mechanical kick-down rod and
>lever,
Oh my god can you possibly be more wrong, goat----er?
--
Just your average Joe.
04-25-2006, 07:35 AM
#37
Guest
Posts: n/a
Re: 90 XJ AT shifting / TPS problem
On Fri, 24 Mar 2006 19:17:49 -0800, L.W.(ßill the goat ----er) ------
III <----------@***.net> wrote:
> The Throttle Position Sensor is like a mechanical kick-down rod and
>lever,
Oh my god can you possibly be more wrong, goat----er?
--
Just your average Joe.
III <----------@***.net> wrote:
> The Throttle Position Sensor is like a mechanical kick-down rod and
>lever,
Oh my god can you possibly be more wrong, goat----er?
--
Just your average Joe.
04-25-2006, 07:36 AM
#38
Guest
Posts: n/a
Re: 90 XJ AT shifting / TPS problem
hOn 24 Mar 2006 19:35:59 -0800, JRK58@MSN.COM wrote:
>The TPS on my XJ has 2 pigtails one sends a voltage signal to the
>transmission controller. The spec for the TPS output to the
>transmission controller is about 4v, if it's only putting out .34v
>wouldn't that affect the tranny?
If it gets below 3, yeah. 3.4 isn't that much off from 4. An old
battery could cause that minute difference and your tranny would still
work. It'd also still work right at almost 5 volts.
--
Just your average Joe.
>The TPS on my XJ has 2 pigtails one sends a voltage signal to the
>transmission controller. The spec for the TPS output to the
>transmission controller is about 4v, if it's only putting out .34v
>wouldn't that affect the tranny?
If it gets below 3, yeah. 3.4 isn't that much off from 4. An old
battery could cause that minute difference and your tranny would still
work. It'd also still work right at almost 5 volts.
--
Just your average Joe.
04-25-2006, 07:36 AM
#39
Guest
Posts: n/a
Re: 90 XJ AT shifting / TPS problem
hOn 24 Mar 2006 19:35:59 -0800, JRK58@MSN.COM wrote:
>The TPS on my XJ has 2 pigtails one sends a voltage signal to the
>transmission controller. The spec for the TPS output to the
>transmission controller is about 4v, if it's only putting out .34v
>wouldn't that affect the tranny?
If it gets below 3, yeah. 3.4 isn't that much off from 4. An old
battery could cause that minute difference and your tranny would still
work. It'd also still work right at almost 5 volts.
--
Just your average Joe.
>The TPS on my XJ has 2 pigtails one sends a voltage signal to the
>transmission controller. The spec for the TPS output to the
>transmission controller is about 4v, if it's only putting out .34v
>wouldn't that affect the tranny?
If it gets below 3, yeah. 3.4 isn't that much off from 4. An old
battery could cause that minute difference and your tranny would still
work. It'd also still work right at almost 5 volts.
--
Just your average Joe.
04-25-2006, 07:36 AM
#40
Guest
Posts: n/a
Re: 90 XJ AT shifting / TPS problem
hOn 24 Mar 2006 19:35:59 -0800, JRK58@MSN.COM wrote:
>The TPS on my XJ has 2 pigtails one sends a voltage signal to the
>transmission controller. The spec for the TPS output to the
>transmission controller is about 4v, if it's only putting out .34v
>wouldn't that affect the tranny?
If it gets below 3, yeah. 3.4 isn't that much off from 4. An old
battery could cause that minute difference and your tranny would still
work. It'd also still work right at almost 5 volts.
--
Just your average Joe.
>The TPS on my XJ has 2 pigtails one sends a voltage signal to the
>transmission controller. The spec for the TPS output to the
>transmission controller is about 4v, if it's only putting out .34v
>wouldn't that affect the tranny?
If it gets below 3, yeah. 3.4 isn't that much off from 4. An old
battery could cause that minute difference and your tranny would still
work. It'd also still work right at almost 5 volts.
--
Just your average Joe.