08 Alpha Speed Sensor Problems

[StandoutAlpha]

My 08 Alpha is having a speed sensor problem if anyone can chime in and help Thank You in advance.

The Problem: The speedometer will stop working/moving and the transmission will not shift into the next gear at all. RPM needle works just fine.
NO CODES AT ALL
But I did have a *P2138* once clear it with my BlueDriver OBD App scanner and it never came back

*Possible Causes*
1. I'm using a Pedal Commander
2. I found my front passenger side floor soaking wet so it could be water interfering with the electrical
3. My Service 4WD is on due to after taking out my dash and putting it back must've pinched a wire or something since passenger airbag and seat belt light on the 4x4 switch doesn't light up
even if I have someone siting in the passenger. I haven't fix that yet but drives normal other then the speedometer issue and also just can't switch to 4HI Lock or 4LO Lock -right now its on normal AWD-

*Before anyone says 'its the transmission" FYI I just had the transmission rebuilt a few months back *also including a new INTERNAL speed sensor*

Here's the thing.....
First off it
-Only happens once a awhile *once or twice a month*
-Only on 1st gear *2nd gear and up drives normal*
-When coming to a complete stop and going forward again it goes back to normal *speedometer works again and drives just fine*
-It will also cause *if foots on the gas pedal and I'm trying to increase speed just a little foot pressure will send the Alpha to downshift
or go wide open throttle and the engine screams until I let off to back where it is*
^^^^problem is I ain't trying to floor the pedal I'm just increasing my speed "switching lanes,passing cars, coming out of ramp etc.

What I had replaced the 1st time
-Put in a new output speed sensor *the person who rebuilt my tranny didn't replace that so I did that*
-Still having the same problem but now only does that once every 1 or 2 months *now less likely to happen*

Now this 2nd time I have replaced
-Cut the old speed sensor connector out and solder a new speed sensor connector in *I thought the wire could have a break in it so I replaced that*
-Put in a new output speed senor again *just to pair it up with the new sensor connector*

Still having problems....
-This time the speedometer will stop working/moving every time I drive, every single day, and here and there
-It will only work again if coming to a complete stop and going forward again
-Only on 1st gear still

What else to check or take a look at? Maybe my gauge cluster going bad?
If you made it this far Thank You again for reading this thread..

 

[Guerrero]

Well, hope my answer help you a little, but in your particular case, need to focus in repairing every gremlins because those could be causing your headaches....

First, 2008 H3s have TWO SPEED SENSORS, one internal sensor inside the transmission in the OIL Pump assembly (need to remove the tranny, then remove the oil pump case and then replace Speed Sensor.
The other Speed sensor is the one situated in the Transfer case, is the external Sensor.

So you commented that you replaced the External sensor, I think, sensor+conector, and still having the symptons you describe.
In this moment if I were you, i will look into all the gremlins problem you are having, because your 4WD problems, if are associated to a bad wiring, could be causing the external Speed Sensor problem (the wiring is in the same location for both systems).
Of course check and diagnose the other electrical gremlins you are having because can be messing something (wiring repair are tedious, but a proper diagnostics with multimeter could make things easier)

Its strange your case, because bad Internal Speed sensor always launch a fault code, but Speedometer seems to work correctly, just bad shifting (speedometer seems to be related to external speed sensor). So your 4WD wirings problems, and bad signal from external speed sensor could be relationated

Hope this help you out, and keep us posted

P.d: What did you do to mess with that amount of wiring and possible sources of problem now? Replaced AC fan or something?

 

[StandoutAlpha]

I had to remove the whole dash to replace the old leaky AC Evaporator Core and I put a new one in.. Since then the Service 4WD light comes on.

This car is giving me problems after problems.
I'm just going to take it to a dealership for a diagnostic.

 

[amrg]

Make sure the 4Hi/LO cluster is plugged in properly into the harness in the dash. Could be something this simple

Sent from my SM-G960F using Tapatalk

 

[StandoutAlpha]

For the 4WD light turns out I had 2 wires mismatch plugged in wrong. Now its back to normal and working again.

Still having problems with the speedometer.

Going to replace in a new
-Accelerator Pedal Sensor
-Throttle Position Sensor

Going from there i'll see if it fixes the problem

 

[dacjeep]

I had the same issue..... Replaced connector and wires to the Controller, replaced the speed sensor on the tran, this worked for a couple of years, then it came back. Purchased another speed sensor and it did it again, returned that sensor for another one and took care of the problem. I was told by my Master Mechanic that I need to by OEM sensor. I did not do that. He also told me before I purchased my sensor that I would have to go through a couple of those to get one that worked. He was right. Something to do with the tolerance range quality standards with third party parts.