kdclaiborne

Help me out here. I have a set of manuals, but thought I'd throw this out to the forun ZGuru's:

Just picked up a clean well-maintained 02 EB Z06 last November. If I'm not mistaken, this car has a reverse lock-out switch on 6speed tranny to prevent shifting into Reverse while moving in any forward gear. Mine either isn't working or has been disconnected as I can accidentally shift into Reverse at highway speeds.

I may be off, but I'm guessing that someone may have mistakenly disconnected both CAGS and Reverse Lock-out as I think they are near each other and look similar. CAGS has also been disconnected/disabled. When it gets warmer, I 'm going to lift to check a few things, change oil and tranny fuild (even tho GM says you don't have to...).

What do I need to check?

u4ick

I've had this problem myself.
I accidentaly hit reverse shortly after getting my car (only had 1,400 miles when I got it).........obviously it didn't go in but made that horrible grinding when I bumped into it. I was on the highway and going into 5th under heavy load when it happened. And I don't think it happened again for quite some time....more than 2yrs.
Then all of a sudden it was happening periodicaly under normal driving conditions.......it would just fall over to reverse, and would be difficult to find 5th, it just wanted to keep trying for reverse. So I replaced the solenoid and problem solved.
Others here have had the same issue, so I think it's somewhat common.
I say check your wiring..........if it's worked correctly before then it's probably not the wiring (unless something has come loose......doubt it though as they have a locking type plug).....and with all things electrical....if it's happened once it will happen again. Just change it out and forget it........you certainly don't want it happening again at an inoportune moment.

BlackZ06

You say you are shifting into reverse at highway speeds ?????????

I doubt it ... if you try for reverse in ANY manual car at highway speeds you will hear a HORRIBLE grinding noise .... you will NOT be able to actually select reverse. The reverse lockout is simply there to protect the gearbox from you being able to "grind" the gears, as over time that will damage the gearbox.

Want to test my theory ... remove Fuse # 19 from the Underhood Fuse Block ..... accelerate car to 60 MPH and select REVERSE .......

NOTICE: I AM NOT RESPONSIBLE FOR DAMAGE TO YOUR TRANSMISSION

What kind of gearshift lever is installed in your car ... aftermarket or OEM ???? Sounds like yyou "think" you are selecting reverse, you are actually selecting some forward gear ... which one is a good question.

One option is, after you "think" you selected reverse ... bring car to a stop while holding clutch pedal to the floor ... now carefully see if you are actually in reverse or another geAR ... I'LL BET YOU'RE IN 5TH.

heavymetals

T56 has a reverse lockout solenoid.

Common failure.

cbogwill

I think you've posted something along these lines before (or someone has). Clearly you have never had this solenoid fail...

When you attempt to hit 5th, you can feel that the "gate" that blocks reverse isn't there. If you aren't paying attention if this happens, you will grind (actually getting into reverse isn't going to happen).

I've driven a car where the solenoid would work intermittently. It sure does feel weird.

Bill Hilt

part# for the solenoid please can it be tested ?

BlackZ06

Part number is 12523300 for the solenoid, there ia an O-ring listed as 12523203 for the solenoid.

The PCM controls the solenoid by applying GROUND to the circuit, in other words the solenoid is ALWAYS supplied power through Fuse 19, the PCM turns it ON/OFF by controlling the ground for the circuit. A P0801 should be set if the PCM determines an "out-of-range" voltage condition on the circuit.

Bill Hilt

Well iI finally got around to removing my selonoid . I would say its on the passenger side if you asked me btw. I think the spring is broken in the housing it mounts to . Is there a part number for that piece ?

Deviant LS6

If the lock out solenoid is unplugged or bypassed it will not allow you to go into reverse. You can overcome the unpowered solenoid by using lots of force (usually two hands) and it will be be very stiff to go all the way over right. If your shift solenoid is allowing you to go over towards reverse without any resistance I would venture to say that the solenoid itself it bad.

The solenoid is on the passenger side of the tranmission and up high. I've taken one apart and it's just two springs, a rod and an acuator. One of these have failed. I doubt they sell the individual parts. You're better off buying a new reverse lockout solenoid.

fishdude7

I've had this problem in my vette as well. What deviantLs6 said is right. I had a clutch installed, and the solenoid was left unplugged. I couldnt get into reverse because there was no power going to the solenoid to allow it the open. Your problem is that the solenoid is bad, and is stuck in the open position allowing you to get into reverse when shifting into 5th gear. If you can shift into reverse when the car is off the switch is bad. I had the same problems that you had, so I replaced the solenoid. When I took the old solenoid out I saw that it was stuck in the open position. I have had no problems with it since then. By the way, I replaced it on my back under jackstands. That sucked. It's really easy to replace it on a lift though.

pluslt

I had this same issue on two separate occasions. Good to know its a relatively easy fix and isn't going to require a trip to the transmission gurus. Good post.

MTPZ06

Congrats, but ummm...4 years later?? If you ever have chest pains, don't wait 4 years to see a doctor.