CCKen

Do you have a scanner that shows live data? Some, if not all, good scanners will show TPS output and TCM input from the TPS. If you do have one, or can rent one, you can watch the scanner instead of reading voltages at the TCM connector. Plug in the scanner, turn key to run, set up scanner to read live data, note TPS output, then depress gas pedal and watch the TOPS output and the TCM input.

If you do read voltages at the TCM connector, a CEL will be triggered when you turn the ignition key to run with the TCM disconnected. You'll have to clear the code when the connector is reinstalled.

I would like to see you read the resistance of the Input Speed Sensor from the TCM connector to see if the wiring is good. Playing with my spare ISS today I read 625 Ohms.

prcherokee

This might help too.

http://library.worldtracker.org/Car%...kee/01XJET.PDF

markcrain

I was reading that info. Thank you for sharing it. I noticed it makes no mention of a 0700 code at all. Any thoughts on that?

prcherokee

Page 3 on top .
IT says that is a PCM code, not a TCM code.

mlepesant

Just for info, I had the same codes back in May. Had the valve body, solenoid, NSS, TPS replaced, with no luck. The trans shop didn't know what was wrong (by the way the OD wouldn't lock up) after several trips to the shop. Rethinking about the many posts I read from Radi or Ken I replaced my positive battery cable end connector which was really in a bad shape and lose (the end of the cable was frayed and the connector was junk. I had done the negative some time ago). The codes haven't reappeared since then and Jeep is shifting great. (Of course as soon as I send this post, it will start behaving again...).
I am not saying that will solve your issue but it is worth doing since it is very low cost and time..
Marc

mlepesant

Highjacking the thread since it is the same topic. Let me know if I should start a new one.

Transmission was rebuilt after 90kmiles. Then rebuilt again (and torque converter changed) after another 100kmiles. Don't know what the codes were then - I was not working on my jeep at this time. The jeep is a 98 sport, AW4, with 334kmiles. Working great otherwise...


Well, so much for my "fix". I had the P0700 and P0740 come back for the past 2 months or so now.
I have used the method provided by Ken in quotes below.
Here are the results of the tests (all tests on TCM plug):
- TCM ground circuit at cavity 24: no resistance.
- Brake lamp switch: little resistance at about 2 ohms (tester fluctuating a lot before settling). No change when depressing the brake pedal.
- Solenoid circuits: 14 omhs on C. 15 ohms on the other 2.
- TPS: no checked. (replaced with a Mopar unit less than a year ago).

Again, the behavior is the following:
"Problem" going out of 1st when cold (it has been doing this for ever so I was led to think that it is normal...); it feels like the car doesn't want to shift out of 1st. It does this until temp reaches maybe 110 or so (or a few shifts) and then it shift out of 1st very well. No issue ever shifting to 3rd. Typically after several stop and go in traffic, it then looks like it doesn't shift into 4th. I can tell this issue is coming because the RPM drop from 1 to 2 and 2 to 3 is very minimal. A few stop and go later, while in 3rd, RPM keep going up. I can drive the jeep at almost 3k RPM for 60mph. I am not really sure if it is actually the torque converter not locking up or if it is not shifting into 4th.
I can tell several times that the converter doesn't lock up since removing my foot from the gas shows a significant and immediate drop in RPM. When the TC locks up, depressing the brake pedal increases slightly the RPM.
I changed the C solenoid about 2 years ago after getting a P0743.
This transmission issue seems to be reoccuring about every 6 months..
I am wondering if the solenoid (1 or 2 can't remember) that controls shifting 1 to 2 and 3 to 4 could be at fault. Again, resistance tested when cold is normal.
I use the correct fluid, which is bright red. Due to those issues in the past 2 years I have drained and refilled several times. Level may be slightly high.
Last (but maybe not least), the solenoid connectors are broken (at least 2 of the 3) and are held in place with zip ties (Yes I know... but last time I dropped the pan they were still holding the connectors very tight).
Besides testing the TPS (which I will do next week when getting an analog multitester), draining a little bit of fluid to put it at a lower level, what would you suggest I test next?
Sorry for the long post...
Many thanks.
Marc


<<
You may have a bad brake lamp switch, bad TPS signal to the TCM, or wiring from the TCM to the Lock-Up solenoid.

~~~~~~~~~~~

Tests:

You'll need a digital Volt/Ohmmeter.

Refer to the TCM connector pin-out below.

Preliminary

Disconnect battery ground cable at battery. Leave disconnected during the Ohmmeter checks.

Access TCM and unplug the connector.

Check the TCM ground circuit by probing pin cavity 24 (+) to a good chassis ground under the dash. You should read continuity, but no more than 1.0 Ohm resistance. If you see high resistance, the TCM ground point connection should be checked/cleaned. The TCM is grounded at the coil mount bracket stud(s). Two small wire ring terminals and a battery ground cable. Remove and clean the two small ring terminals. Reconnect and read the resistance again.

Brake Lamp Switch

Probe pin cavity 23 (+) to cavity 24 (-). You should see continuity. Move the brake pedal in and out and see if the reading changes. If so, replace the switch. If you see resistance of more than 5.0 Ohms at any time, replace the switch.

Solenoid 'C' circuit wiring

Measure the resistance between cavity 11 (+) and 24 (-). You should see 11 to 15 Ohms resistance (solenoid resistance spec). With a new solenoid installed it should be within spec. If not there may be a wiring fault between the TCM and the solenoid.

TPS Checks

If any fault was found and corrected in the above checks you may not want to be bothered with this check.

To proceed,

Reconnect the battery ground cable at the battery.

You'll be checking the TPS output voltage to the TCM.

Set voltmeter to 20 VDC scale.

Turn ignition switch to ON (run) without starting the engine.

Measure the TPS input voltage by probing cavity 17 (+) to cavity 16 (-). At idle you should read between .26 V and .95 V. While still connected, depress the gas pedal slowly to WOT and watch the Voltmeter. The voltage should increase smoothly to 4.49 volts, or less.

You may not have been experiencing TPS performance problems but the lack of good voltage to the TCM may cause your problem.

Completion

Disconnect the battery ground cable before reconnecting the TCM connector.

Tell us what you find. >>