AW4 does not shift - help me finish troubleshooting

[bigalpha]

did you get a resistance value for your solenoids?

Yes:

- Yes, I tested the wires to the solenoids at the TCM connector and at the connector under the hood. C14 0 ohms, C15 gave some real high reading 30-50 ohms, C16 0 ohms.

 

[90xj06]

what was the values for the solenoids?

just unplug the connector and get a resistance to them. im going to go put my jeep in the garage and look to see if i can give you a detailed procedure.

 

[bigalpha]

Those values I gave you were with the TCM unplugged, tranny in 'Park' and ignition 'OFF'

 

[90xj06]

if you can unplug the solinoids and test them. power off. they should be 11- 14 omhs.

 

[bigalpha]

if you can unplug the solinoids and test them. power off. they should be 11- 14 omhs.

Yeah, I wanted to drop the pan as a last resort. I wanted to be doubly sure nothing else was causing this issue.

What do you make of the 0V speed sensor, and the low voltage for the TPS?

 

[90xj06]

the tps sensor would make it shift sporadic. but you have a manual shifting which is lack of power. so the transmission does not know what to do. im going to try to find the plug or connector to avoid removing the pan.

 

[90xj06]

do a resistance check from pin d7 - c15 and d7 -c16 and see what you get.

my guess is there is a gray connector on the right side of engine. i think its either corroded or unplugged.

 

[bigalpha]

d7-c15 = 30-40ohms. This flucuates between measurements. However, when I am actively measuring, the ohms do not flucuate. They only change between startups sometimes.

d7-c16 = 0 ohms.

There is a connector on the passenger side of the engine bay. I unplugged it and tested that as well. I received the same amount of resistance. The connector/wiring is in good shape. No breaks, tears, melts, shorts.

From there, however, I'm not exactly sure where the wiring runs. I know it probably runs down the firewall, but I can't seem to trace it myself.

 

[bigalpha]

So, I went back out and re-measured the resistance of C15 and got .... 16 ohms :dunno:

 

[90xj06]

just to see whats the resistance from d7 to the negative side of the battery?

on the test you did d7 is the ground c14 is solenoid 3 c15 is 2 and c16 is 1.

c15 ohms seems normal.

now just to make sure put the meter in ohms and touch the 2 leads together it should read 0.

 

[bigalpha]

Yeah, I already verified the meter was working by touching the leads together and it was 0.

Can't check d7 to batt neg right this second, but should be able to after work.

 

[B.RAIDER]

There is a connector on the passenger side of the engine bay. I unplugged it and tested that as well. I received the same amount of resistance. The connector/wiring is in good shape. No breaks, tears, melts, shorts.

From there, however, I'm not exactly sure where the wiring runs. I know it probably runs down the firewall, but I can't seem to trace it myself.

Just a thought here...... see if you can disconnect the wiring plug from the TCU and the under hood connector and see what your resistace shows there ....you'd be checking that wiring from the TCU to the under hood connector for any problems in that wiring and rule it out for sure.
Hope that makes sense.

Got your pm....... It was explained to me a while back and as best as I could explain it is ......the solenoids do the shifting "electronically" thru the TCU and when there is no power or correct signal to the TCU it defaults to the "manual" shifting mode which is done mechanically thru the linkage.
I know someone on here can explain it better than I just did.

 

[bigalpha]

Just a thought here...... see if you can disconnect the wiring plug from the TCU and the under hood connector and see what your resistace shows there ....you'd be checking that wiring from the TCU to the under hood connector for any problems in that wiring and rule it out for sure.
Hope that makes sense.

Got your pm....... It was explained to me a while back and as best as I could explain it is ......the solenoids do the shifting "electronically" thru the TCU and when there is no power or correct signal to the TCU it defaults to the "manual" shifting mode which is done mechanically thru the linkage.
I know someone on here can explain it better than I just did.

I already tested the resistance on the plug going to the TCM. So, I unplugged TCM and underhood connector. Plug going to TCM, C14-16 all read 0 ohms.

Ah, I gotcha. That makes perfect sense.

 

[B.RAIDER]

I already tested the resistance on the plug going to the TCM. So, I unplugged TCM and underhood connector. Plug going to TCM, C14-16 all read 0 ohms.

Ah, I gotcha. That makes perfect sense.

So, if I understand all that has bee discussed here, and I understand that you have went thru the Shift Pointers checklist, all is well up until you get to the wiring going from the underhood plug to the transmission. It would be my in my thinking you have narrowed it down to that particular set of wires and the solenoids.
But wait........somewheres I recall a mention of the NSS could be a problem also, something as to it's gotta know where the gear selector is set in order for the TCU to well you know :banghead:......

 

[bigalpha]

Well, the TPS reads a little low ~3.7V.
The Speed Sensor shows 0V.

I don't have any classic NSS symptoms.

**Actually, the Speed sensor shows the correct voltage, but it doesn't cycle because I can't rotate anything by hand while i'm testing. i assume it's good though.

 

[90xj06]

heres the schematic i was using to figure out the problem. you need to test the gray connector down to the tcu connector. measure it with both connectors disconnected and the jeep key off. on the lowest resistance setting. it should be very close to 0

 

[bigalpha]

The diagram shows a red x.

 

[90xj06]

try going here.
http://www.teamkov.ath.cx/tcu.jpg

 

[bigalpha]

try going here.
http://www.teamkov.ath.cx/tcu.jpg

No dice. I am at work, so maybe they are blocking it.

 

[90xj06]

that's probably what it is. i just confirmed it does work.