700r4 tcc emergency help

[Backwoods_BC]

I need some emergency help, Im driving a 91 6.2 4x4 with a 700r4, and I am in the middle of moving, Im 600 miles from home! The transmission is not locking up, Its shifting fine otherwise. I am towing a small trailer, but its not locking with or without the trailer hooked up. I am getting 9 to 10v at the ALDL terminal, and 0.30v when it should be locking. The brake switch is cutting power completely (0v) upon braking. TCC solenoid has resistance of 13 ohm between connection and ground. TPS shows 5v at one wire, and has variable resistance through out throttle range on the other. Does this sound normal? Can I disconnect the solenoid and just drive it without being locked? Is there any other things I should be checking? Thanks for any help!

[DmaxMaverick]

Check the ECM for codes. Something as simple as a temp sensor (bad connection, or just bad) can prevent TCC lockup.

[Backwoods_BC]

Check the ECM for codes. Something as simple as a temp sensor (bad connection, or just bad) can prevent TCC lockup.

OBD1 system shows code 21, (TPS circuit high?) Will it cause damage from driving without lockup?

[Backwoods_BC]

BM Racing transmissions states that their torque converter can be run with or without lockup, simply by cutting the power wire (purple wire, pin a) I am presuming that it will be fine on a stock one as well, as this is what the brake switch does. I also found that the tcc solenoid should have approx 20 ohms resistance, so this may be my problem.

[DmaxMaverick]

OBD1 system shows code 21, (TPS circuit high?) Will it cause damage from driving without lockup?

If the circuit is high, it will prevent a lockup (anticipating full throttle acceleration). Start by checking the connection and harness. 13-20 ohms difference is insignificant. It's a solenoid coil, and should be nearly closed (such as 20 ohms), in any case. The 7 ohm difference is well within the margin of error of most consumer type meters, anyway. A little corrosion in a connector can cause more than that. Make sure you are checking the correct polarity, as many of them have a diode (which may indicate different resistance, depending on the polarity). Older electrical systems are often further from OEM spec than new, as well. If the circuit was open, it may indicate a bad coil.

Driving with the TC unlocked won't hurt, unless you allow it to generate excessive heat. Light loaded, easy driving won't hurt, especially this time of year (and colder). Mileage will suffer during highway driving. If your TPS is dead, it's easy enough to fix, and not too expensive. They rarely fail, so a used sensor would probably be OK.

I do not recommend "cutting" a wire to "fix" the issue. If it's only a matter of the TPS, fixing that should return normal operating.

[Backwoods_BC]

Well I made it home Ok. Thanks for the advice. Now to troubleshoot and repair the problem. BTW, I never cut any wires, I simply unplugged the connector at the transmission. I figured at least the transmission wouldnt be trying to lockup, if it is a TCC clutch issue, and cause more damage to it. I will start a new thread as to the troubleshoot\repair of this issue. Thanks again.

[sholsten]

I burned my 700R4 out one time driving it 65 mph for 100 miles over a blown fuse.