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AW4 does not shift - help me finish troubleshooting

I went out and tested through the entire connector (while it was unplugged) using the "Shift Points" document and these are the only anomolies:

C3 (Speed Sensor): 0 Volts
C9 (Drive Input): 0 Volts
C14 (S3): 0 ohms
C15 (S2): 23.8 ohms
C16 (S1): 0 ohms
 
bigalpha said:
I went out and tested through the entire connector (while it was unplugged) using the "Shift Points" document and these are the only anomolies:

C3 (Speed Sensor): 0 Volts
C9 (Drive Input): 0 Volts
C14 (S3): 0 ohms
C15 (S2): 23.8 ohms
C16 (S1): 0 ohms
Click to expand...
How did the rest of the test come out?
Were they within the specs of the chart using all the guidelines of each test?

Also, It has been stated over and over about bad grounds on our rigs.
If I missed it in any of your post (forgive me) .... you need to verify that all your grounds from the battery are good. If your battery to block and block to chassis are bad it would mess with the ohms readings.
You stated that your c15 readings were jumping 0-34....this could be part of your problem.
I know it's a headache trying to figure this mess out, but hang in there you will get it fixed. It took much reading...searching and more reading before I found my problem...with a little help from Ecomike also.
 
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Everything else I tested came out within specs. These were the only significant variations.

Sure seems like a lot of problems :scared:

For all but the solenoids, are they supposed to be tested with the connector plugged in?
 
bigalpha said:
If I can manage to find those two squarish plugs, do I need to disco them to test the solenoids?

So, it'd be: ignition 'ON', 'Park', and unplugged?
Click to expand...

I would unplug them and check the end going down to the trans. Doesn't matter if the ignition is on. I would recommend being in park though if you're poking around under the hood. :}
 
lawsoncl said:
I would unplug them and check the end going down to the trans. Doesn't matter if the ignition is on. I would recommend being in park though if you're poking around under the hood. :}
Click to expand...

When I did that, I received 0 ohms at all three ports (C14-16).

Now, when I did this at the connection at the TCM, I received 0 ohms if I used a chassis ground and 23.8 ohms if I used the ground in the connector (only at C15).

Will I need to find the ground wire for this connector and use that instead of a chassis ground for an accurate measurement?
 
bigalpha said:
Now, when I did this at the connection at the TCM, I received 0 ohms if I used a chassis ground and 23.8 ohms if I used the ground in the connector (only at C15).

Will I need to find the ground wire for this connector and use that instead of a chassis ground for an accurate measurement?
Click to expand...
I'm still thinking you have a chassis ground problem (partial problem anyways)starting at your battery.
So your saying that at D7 on the connector you have 23.8 ohms and if you ground it to the chassis somewheres you get 0 ohms?
 
B.RAIDER said:
I'm still thinking you have a chassis ground problem (partial problem anyways)starting at your battery. So your saying that at D7 on the connector you have 23.8 ohms and if you ground it to the chassis somewheres you get 0 ohms?
Click to expand...

I don't really have any symptoms of a bad ground, I don't think. I suppose the best way to test a ground is by using a meter to test between chassis ground and positive on battery?

Yes, that's what I'm saying. But, I can test D14 and D16 on the same chassis ground and I get the same reading as when I test it using D7.
 
bigalpha said:
I suppose the best way to test a ground is by using a meter to test between chassis ground and positive on battery?
Click to expand...
Set your meter to ohms and touch the ground side of the battery to your engine block and then your ground strap on your firewall. I just did mine and I got 0 OHMS at both checkpoints.
Are you using a digital or analog meter?

After re-reading all the post, I am inclined to believe you have a shorted wire somewheres between your TCU and the transmission.

I would start with the connection that lawsoncl mentioned (squarish plug) in the engine compartment at the firewall to the transmission.
You could have a melted wire or something of that nature.
I'm no electrical guru by any means, but if you are getting a reading of 0 ohms at the square plug mentioned (with it disconnected), to me that points to shorted wire(s) from that plug to the tranmission or TCU (depending which end of the plug you test).
If you can verify that the wires are good....then you just might need to drop youe transmission pan and check the solenoids that way.
 
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B.RAIDER said:
Set your meter to ohms and touch the ground side of the battery to your engine block and then your ground strap on your firewall. I just did mine and I got 0 OHMS at both checkpoints.
Are you using a digital or analog meter?

After re-reading all the post, I am inclined to believe you have a shorted wire somewheres between your TCU and the transmission.

I would start with the connection that lawsoncl mentioned (squarish plug) in the engine compartment at the firewall to the transmission.
You could have a melted wire or something of that nature.
I'm no electrical guru by any means, but if you are getting a reading of 0 ohms at the square plug mentioned (with it disconnected), to me that points to shorted wire(s) from that plug to the tranmission or TCU (depending which end of the plug you test).
If you can verify that the wires are good....then you just might need to drop your transmission pan and check the solenoids that way.
Click to expand...

I am using a digital meter, as I don't have access to an analog one (without buying one).

I tested the neg battery terminal to the battery ground on the engine block and got .2 ohms.
I tested neg battery terminal to the strap on the firewall and got 1.2 ohms.

I tested the plug on the firewall and both ends of the plug received 0 ohms. The wiring appeared to be in good shape with no melting, breaks or burn marks. The wiring still has the shrink wrapping on it from start to end.

I'll crawl under the Jeep and try to check the wiring and verify it's not ripped or broken. Is there a way to test the Speed Sensor and make sure it's working properly?

I'm trying to drop the pan as a last resort, lol.
 
Is there a scan tool that can plug into teh TCM or something that can run all the diagnostic tests and punch out any errors?
 
did you test the wires to the solenoids?
and the computer is getting power?
did you back probe the connectors to see if the computer is sending a signal to the solenoids. are the solenoids receiving the signal.
the check engine light is not lighting the computer sees the tcu as working correctly.

more over when did this start happening? did it just stop working one day? im going to get a copy of the fsm and see the wiring on it. but i would imagine its the same on the 90.
 
- 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.

"did you back probe the connectors to see if the computer is sending a signal to the solenoids. are the solenoids receiving the signal. "
- How do you do this? Do you backprobe the solenoids with the connector plugged in?

- The CEL is NOT illuminating.

- I bought the Jeep with this condition.

- I finished backprobing the whole TCM harness following the "Shift Points" document. I got 3.7V for the TPS and 0V for the Speed Sensor.

- The TPS is putting out ~3.7V at the connector at the TPS as well.
 
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