O/d Light Flashing

[tleader]

The O/D light is flashingin my 91 LS400. The tranny seems to be working fine, with no mishaps. The O/D switch works, and when it is switched on, the light starts to flash, but the car DOES go into overdrive. I have not noticed any problems thus far, but according to the manual, it is saying there is a major transmission failure. Anyone got any ideas, or know if there is a sensor out? Could it be the beginning of a transmission failure? Any help would be appreciated.

[LinuxFan]

I actually had this happen to my 91 once. Has not happend again and except for the trac light being on (still working thru that to find a cause), everything works fine.

any ideas

[VMF]

might mean that you got an error code? have you car checked for codes

[LinuxFan]

Yeah -- that is the plan today, if not then for sure some time this weekend. Let you know what I get.

[SKperformance]

It is usually because there is a torque convertor lock up problem.

[90LS400Lexus]

My old 91 Honda Accord had a "S" light (meaning sport shift mode) that let you know if you was in "sport" shift, rather than normal. It started flashing on my car. According to the owners manual- it signals transmission problems if it flashes. I noticed that the speedometer was also fluctuating as well. Also too- when it would flash- it would not go into 4th gear (overdrive). It turned out to be a bad speed sensor on the transmission. Replaced it and all was fine. Although I have no idea- it may be a similar problem on your car. Does the speedometer fluctuate at all? If the transmission is shifting well and it seems to be going into "lock-up" OK, then I would just drive it. It may just be the sensor that controls the "O/D" light is going out. I have no idea. Perhaps someone else here will have more insight on this.

[LANLEX]

The O/D light is flashingin my 91 LS400.  The tranny seems to be working fine, with no mishaps.  The O/D switch works, and when it is switched on, the light starts to flash, but the car DOES go into overdrive.  I have not noticed any problems thus far, but according to the manual, it is saying there is a major transmission failure.  Anyone got any ideas, or know if there is a sensor out?  Could it be the beginning of a transmission failure?  Any help would be appreciated.

←

I'm a new Lexus member. My 1991 LS400 has the same problem, the O/D Off light is flashing. What have you found out. Your help is greatly appreciated.

[90LS400Lexus]

Hello and welcome!

As stated, my old 1991 Honda Accord LX sedan did this as well. Owners manual stated that it meant transmission required service. Turned out being a bad transmission speed sensor on the transmission. I have no idea if this could be a LS400 problem or not.

[LANLEX]

Hello and welcome!

As stated, my old 1991 Honda Accord LX sedan did this as well.  Owners manual stated that it meant transmission required service.  Turned out being a bad transmission speed sensor on the transmission.  I have no idea if this could be a LS400 problem or not.

←

Thanks for your suggestions. Also my cruise control does not engage. The cruise control light is lit on the dashboard, but when I tried to set, it would not engage. Well I took my 91 LS to the Lexus dealer and they said the ECU was bad. It needs to be replaced at $1567.00 plus labor. Ouch!! Well I think I'll live with it for now. The car runs fine, it shifts nicely.

[VBdenny]

I found this question on the UK LOC site. Maybe you could email the poster and see if they found anything out. Sometime I think Lexus ought to put a light on the dash that is green and shaped like a dollar sign.

Donalex Nov 7 2004, 10:30 AM Post #1

New Club Member

Group: Members

Posts: 1

Joined: 7-November 04

Member No.: 8043

Location:Warsash, England

Lexus Model:LS400

I have an early LS 400 (1991) fitted with a 3 speed plus overdrive transmission.

A few miles into any trip I get the amber O/D light flashing slowly. The main dealer refuses to tell me what this indicates.

Can anyone out there with a workshop manual advise what this little amber light is trying to tell me please?

Thanks in advance,

Don Alexander Warsash, England

http://www.lexusownersclub.co.uk/forum/ind...showtopic=17728

[pachocco1]

For certain it is an error. Get this looked at as soon as possible.

If you are a DIYer, I have attached the resolution to whatever trouble code you have.

You can get you trouble code byfollowing the instructions on this link.

trouble code

circuiti.pdf

[BogeyJH]

Using the code reading tutorial from LexLS.com, I got error code 42 indicating a problem with the #1 speed sensor circuit (backup sensor). The car shifts normally and exhibits no hint of a problem other than the flashing indicator. Each time I drive the car, it takes some time for the O/D OFF indicator to start flashing, which I don't believe is indicative of a reset in the circuit with each drive cycle.

Since electronics sometimes glitch and need to be hard rebooted, I decided to pull the 20A EFI fuse to reset the ECU, clearing the stored codes. I then drove for a good distance with no indication of a problem (no flashing indicator).

UPDATE:

The issue returned after remaining dormant for quite a while. Now pulling the fuse to reset the ECU only resolves the flashing O/D OFF indicator for one run cycle. Once the car is started a 2nd time, the flashing is back. Also, the cruise control will not engage with the fault condition present. I guess I'll have to look into this further.

Bogey

updated June 20, 2009, 12:35 PM