Help. having transmission problems

[dentonz]

I have an 01 trooper ls 4wd auto with 89k. It will not shift out of first gear, but easily shifts into r/d/p. There was no warning this just happened suddenly. Can this be just a sensor/electrical problem or something more serious.

Thanks

[trooperbc]

Originally Posted by dentonz

I have an 01 trooper ls 4wd auto with 89k. It will not shift out of first gear, but easily shifts into r/d/p. There was no warning this just happened suddenly. Can this be just a sensor/electrical problem or something more serious.

Thanks

i'm not sure i understand.
**when you drive in D Drive, the trans doesn't upshift after starting off in L 1st gear?
or
**mechanically, when you 'manually' shift into L, you can't get it out of that position at the shift lever?
or
**the gear selector indicator lights at the dash don't change, i.e. it says L even when you *know* you are in a different gear?

if the latter, then i'd say it was the gear selector Mode Switch/Sensor.

check out these posts, which also have links to other posts describing symptoms
http://www.4x4wire.com/forums/showfl...&Number=902938

also check out FAQ, #59 i believe
http://www.isuzufaq.com/

hth

let us know some more info as it applies


\\
//bc

[stompin60]

It sounds like it is limp mode, which can mean it is fried, but there are other alternatives to troubleshooting it.

Here is one thread that people have trouble with the voltage , but there are others on this site too.

http://forum.planetisuzoo.com/viewto...ight=limp+mode

[dentonz]

Originally Posted by trooperbc

i'm not sure i understand.
**when you drive in D Drive, the trans doesn't upshift after starting off in L 1st gear?
or
**mechanically, when you 'manually' shift into L, you can't get it out of that position at the shift lever?
or
**the gear selector indicator lights at the dash don't change, i.e. it says L even when you *know* you are in a different gear?

if the latter, then i'd say it was the gear selector Mode Switch/Sensor.

check out these posts, which also have links to other posts describing symptoms
http://www.4x4wire.com/forums/showfl...&Number=902938

also check out FAQ, #59 i believe
http://www.isuzufaq.com/

hth

let us know some more info as it applies


\\
//bc

To clarify, When it is in D it will not shift out of low gear. Even by manually selecting gears, it will only shift into low gear. However, it has no problem going into reverse or back into drive. It will not up-shift at all.

[atfdmike]

Hi, if the trans is in backup mode, you would be seeing a check lite and the trans would behave as follows:
Backup Mode
If a major system failure occurs which could affect safety or damage the transmission under normal vehicle operation, the diagnostic system detects the fault and overrides the Powertrain Control Module (PCM).



The "CHECK ENGINE" light comes on and the "CHECK TRANS" light flashes to alert the driver, and the transmission must be manually shifted as follows:
Shifts are firmer to prevent clutch slip and consequent wear. The fault should be corrected as soon as possible.
Also, if you want to look at selector switch, then:
2001 Isuzu Truck Trooper LTD 4WD V6-3.5L

Vehicle Level Transmission and Drivetrain Transmission Control Systems Transmission Mode Switch, A/T Service and Repair Service and RepairREMOVAL

1. Place selector lever in neutral.
2. Disconnect battery ground cable.
3. Remove mode switch cover (1).
4. Disconnect selector lever (2) from the mode switch.
5. Disconnect transmission harness from the mode switch connector (3).
6. Remove bracket with mode switch connector from the transmission case.

1. Remove mode switch connector (3) from the bracket (4).
2. Remove two mode switch bolts and nut then remove mode switch (5).

INSTALLATION
To install, follow the removal steps in the reverse order, noting the points;

1. Torque Mode switch bolt: 13 Nm (113 inch lbs.) Selector lever nut: 23 Nm (17 ft. lbs.)
2. Mode switch setting procedure Perform either of the following adjustment procedures: Procedure 1

1. Place selector lever in neutral.
2. Remove selector lever from the mode switch.
3. Remove the mode switch cover.
4. Loosen the two 10 mm screws.
5. Rotate the mode switch until the slot in the mode switch housing aligns with the selector shaft bushing, and insert a 3/32 inch (2.4 mm) drill bit or punch (1) into the slot.
6. Tighten the screws to 13 Nm (113 inch lbs.) .
7. After completing adjustment, snap the mode switch cover into place.
8. Reinstall the selector lever. Procedure 2

1. Place selector lever in neutral.
2. Disconnect transmission harness connector from mode switch connector.
3. Remove mode switch connector with bracket from the transmission case.
4. Connect multimeter (resistance mode) to terminals 1(E) and 4(H) on mode switch connector.
5. Loosen two mounting screws.
6. Rotate mode switch slightly in both directions to determine the range (approximately 5 degrees) of electrical contact.
7. Position mode switch in middle of contact range.
8. Tighten two mounting screws.
9. Remove multimeter and install mode switch harness connector with bracket to the transmission case.
10. Connect transmission harness connector to mode switch connector.

If you are getting a check trans light, then codes should be set and available to read via the Tech 2 tool. If not, then I don't think any harm would come of checking the shifter switch and making sure that it is clean, adjusted properly and you should be able to search this forum for others who have had similar experiences. Good luck , hope this helps.

[trooperbc]

Originally Posted by dentonz

To clarify, When it is in D it will not shift out of low gear. Even by manually selecting gears, it will only shift into low gear. However, it has no problem going into reverse or back into drive. It will not up-shift at all.

wow. that's strange.
any more info?
***check trans light -- has it come on when driving?
(it does come on when yu first turn the key, right? my 92 has the light in an awkward place and i didn't notice it wasn't lighting until my trans started acting up and i went looking...)

***atf fluid checks -- the color checks out ok? no burnt odor? the level is ok?

***it's not in limp mode, that's for sure. limp mode puts you into 4th starting off when in D, not L 1st. and it 'encourages' you to manually shift.

***mode switch -- i've not heard of, nor experienced this symptom for mode switch problems. but...if all else checks out ok, it might be worthwhile to disconnect the mode switch/harness connector and use an ohm meter to verify continuity between the appropriate terminals for each gear selected.
but, i'm real skeptical that it's this switch; you should be able to manually shift OK, but if there are no other leads. . .

(btw, did you check out any of those links i gave you?)

shift linkage(s) -- have you crawled under there and actually looked at the linkage while someone else shifts? see anything?

charging system -- well it is desperate time. no doubt these electronically-controlled transmissions are *very* sensitive to even minor charging system deficiencies; but again, this particular symptom, doubtful, but. . .

at this point, i'm just guessing with you, and throwing out ideas. post any additional info you have -- re: trans fluid, conditions when it happened, any changes since, etc.

[dropsnout]

If the trans seems like it wants to shift but doesn't it probably had an internal hard part failure. Sounds like you probably need a transmission.

[dentonz]

Originally Posted by dropsnout

If the trans seems like it wants to shift but doesn't it probably had an internal hard part failure. Sounds like you probably need a transmission.

Thanks, I'm having it rebuillt as we speak.

[trooperbc]

Originally Posted by dentonz

Thanks, I'm having it rebuillt as we speak.

wow. only 5 years and 89,000 miles. ouch.
did they say why?

was it covered by warranty?
are they rebuilding or putting in oem factory remanufactured unit?
is it the dealer?


just trying to get educated. thanks.

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\//bc