1994 4runner limp mode transmission

have vehicle scanned for trouble code[s]

Sounds like it goes into "limp mode" sometimes this happens to keep from damaging transmission. Transmission may be over heating or low on transmission fluid.

Sounds like you have a failiing transmission, faulty selector, or possibly a failing Transmission ECU. There are too many possible causes to even guess, but what I can tell you that 'limp mode' will not prevent your vehicle from Driving - It will, however, enable a vehicle with certain failing systems to be driven short distances at limited speeds (with decreased power), but it does not prevent the vehicle from moving - If your vehicle starts but does not move when placed in gear, the problem is not 'limp mode' but lies elsewhere.

probably not if it is limp mode
the ECM puts the car in limp mode to prevent serious problems in the engine or transmission
could be no coolant, sump oil , transmission oil etc
run the fault codes and find the reason for the mode

If it's in limp in mode it won't shift out of 2nd gear. Get the trouble codes read. The solenoid pack is a pretty common failure. But don't just throw parts at it. Get the codes first.

Of course the first thing to do is to check the transmission fluid level. Next have car scanned for codes, if there is a speed sensor malfunctioning, the transmission would go into limp mode. In limp mode, only reverse and second gear work. Many auto parts stores will scan your car for free. I hope this helps.

Before guessing at transmission problems, check the fluid level (car warmed up, engine running in Park on level ground) and have the PCM scanned for trouble codes FIRST. This guide is meant for problems that do not show up as PCM codes (like shift A&B solenoid failures, for example).
Also note that many problems that show up as transmission issues are actually PCM or electrical, and may be external to the transmission. Try a different PCM, and check for chafing where the cables come out of the PCM.
NOTE:The transmission is on the same fuse as the MAF, O2 sensors and at least one other sensor - if an O2 shorts out, it will blow the fuse and the trans will go into limp-home mode. Be sure the trans has power and the fuse is not blown before doing anything else.
What is "limp-home mode" ? This is a fault mode in which the transmission either loses electrical power or the PCM deactivates all of the electronics. The transmission will default to max line pressure. The driver will have Reverse and 3rd, with manual 2nd available by putting the gearshift in 2 or 1 (doesn't matter). 1st, 4th, and TCC lockup will not be available. It will not hurt the car to drive it like this for short periods, but use manual 2nd to get the car moving, and be aware that the trans will generate more heat than normal while operating in limp-home mode due to increased torque converter slippage during 2nd gear starts and no lockup in 3rd gear.
Thank you for using fixya and good luck

NOTE:The transmission is on the same fuse as the MAF, O2 sensors and at least one other sensor - if an O2 shorts out, it will blow the fuse and the trans will go into limp-home mode. Be sure the trans has power and the fuse is not blown before doing anything else.

Also note that many problems that show up as transmission issues are actually PCM or electrical, and may be external to the transmission. Try a different PCM, and check for chafing where the cables come out of the PCM.

Secondly, put a line pressure gauge ($55 shipped on Ebay, or visit a local trans shop) on the pressure test port and go for a drive to verify proper line pressure. Base pressure at idle in P,N,OD should be around 70psi and around 140psi in R. Max line pressure should be at least 190psi at WOT in 1st or 2nd, 225psi is optimum. If base pressure is low, trans or pump is worn out. If max pressure is low, check EPC solenoid. If reverse is slow to engage, and line pressure does not come up to at least 130psi in reverse, replace the boost valve with a Transgo 0.500" boost valve (easy fix in pan).

What is "limp-home mode" ? This is a fault mode in which the transmission either loses electrical power or the PCM deactivates all of the electronics. The transmission will default to max line pressure. The driver will have Reverse and 3rd, with manual 2nd available by putting the gearshift in 2 or 1 (doesn't matter). 1st, 4th, and TCC lockup will not be available. It will not hurt the car to drive it like this for short periods, but use manual 2nd to get the car moving, and be aware that the trans will generate more heat than normal while operating in limp-home mode due to increased torque converter slippage during 2nd gear starts and no lockup in 3rd gear.

Trans shifts into gear harshly, car feels sluggish off the line, No 1st, 4th or TCC lockup available, Manual 2nd, 3rd and Reverse are only available gears, CEL is on: Transmission is either in limp-home mode or has lost electrical power. If there are lots of error codes in the PCM, check the fuse that powers the transmission, and if it pops again, look for a short in that circuit like an O2 sensor harness touching exhaust. Otherwise, check PCM codes for a particular fault in the transmission causing the PCM to put it in limp-home mode.

Car goes into gear but feels very sluggish like the brakes are dragging, but it will roll easily (starts out in 4th gear), you manually shift to 2 to get it moving, once it's moving you put it back in OD and the car shifts 3rd to 4th on its own and locks the converter at the appropriate time: ShiftB solenoid failed: Easy fix in the pan. Or a wiring problem from PCM to trans.. or PCM.


Start with the simple things and check the fuse and Wire leads at the ECM's Transmission control module and the transmission it self. Look for any damages to the wire harness and leads. Try disconnecting the wire harness form the clip on the transmission and cleaning it with brake parts cleaner and reconnect and pull the Fuse to the ECM with the ignition on the on position "engine not running" for 10 sec and place back in and start the engine and go for a test drive and see if that reset the transmission. Good luck and keep me posted, we'll get your transmission running 100% again soon.

It sounds like your transmission is going into the limp mode. The transmission goes into limp mode to protect the transmission from major damage. You either need to take it to the dealer or to a transmission shop to have a diagnostic test done.

try checking your transmission control module for burn't resistors or capacitors also try clearing your tcm by pulling the negative side of your battery off for bout 10 minutes and look for any fuses related to the tcm or ecm in your owners manual