Lee Posted December 4, 2005 Share Posted December 4, 2005 Toyota users, I have a very strange problem That I have been trying to solve for years. I have a 1988 Odyssey with the 22RE engine with an Auto Trans. The rear end and been changed to a 4:56 from a 4:10. The engine starts and runs just fine and the Tranny works perfect as long as I am UNDER 3000 feet in elevation. I live at 2700 ft. so I go well over 300 feet all the time. The problem is when I am in OVERDRIVE and go to an altitude above 4000 feet, the tranny shifts out of overdrive and no matter what you do it will not go back into overdrive until I get back under 3000 feet. Even when going down long downgrades at high speeds and your foot off the gas. I have an altimeter in the M/H and it does its shift thing at almost exactly 3000 and 4000 feet. This was confirmed with a GPS altimeter as well. In all other respects the M/H runs great and gets good gas mileage. I have checked all the vacuum hoses and wiring that I can and have found nothing wrong. Any Ideas? I also have read that a lot of owners would like to have bigger fuel tanks. Mine holds 30 gallons in two tanks. The aux tank is connected to the main tank with crossover tubes. The second tank is filled from the original during fill ups. During use, the main tank is filled from the aux tank. This eliminates the need for a large second filler tube and the need to fill the aux tank from the other side of the M/H. You will need high and low crossover tubes to allow both fuel and air to move from one tank to the other. Both tanks are located at the same height and on either side of the drive shaft, side by side. Works just fine. Gauge sending unit works for both tanks, no problem. Jackson Hole Wy to Jackpot Nv with no stops. Lee Quote Link to comment Share on other sites More sharing options...
Gulfstream Greg Posted December 4, 2005 Share Posted December 4, 2005 Hi Lee There is a device that senses altitude and cuts out the overdrive. Not exactly sure where its at. Later today I will pull out the service manual and give you a better description. So just so you know its not a defect, its a default. Greg Quote Link to comment Share on other sites More sharing options...
Lee Posted December 5, 2005 Author Share Posted December 5, 2005 Hi Lee There is a device that senses altitude and cuts out the overdrive. Not exactly sure where its at. Later today I will pull out the service manual and give you a better description. So just so you know its not a defect, its a default. Greg Thanks a lot Greg. I will be waiting for your second reply. If anyone would like more info on the fuel tank upgrade, just let me know. I also installed a large power inverter, a 100 watt solar panel charge system and a second coach deep cycle battery. Lee Quote Link to comment Share on other sites More sharing options...
ralph Posted December 12, 2005 Share Posted December 12, 2005 Thanks a lot Greg. I will be waiting for your second reply. If anyone would like more info on the fuel tank upgrade, just let me know. I also installed a large power inverter, a 100 watt solar panel charge system and a second coach deep cycle battery. Lee got any pictures of those gas tanks? are they forward of the differential or behind it? Quote Link to comment Share on other sites More sharing options...
neil Posted April 15, 2007 Share Posted April 15, 2007 Help! We've also noticed a problem with the overdrive not kicking in at higher altitudes. Recently bought an '86 Toyota Dolphin & are loving it...but, when going to Death Valley a few weeks ago, the overdrive worked fine while we were in the valley floor (minus 200ft elevation) but not at all when climbing up over the mountain passes while leaving the Valley...what was the answerto your seemingly similar problem?? (without the overdrive our gas mileage is in the toilet ) Quote Link to comment Share on other sites More sharing options...
88WIT Posted April 18, 2007 Share Posted April 18, 2007 As Greg noted, the altitude sensor starts working and the processor doesn't forward the signal to a relay that operates a solenoid mounted on the transmission case. You can bypass the relay easily but I don't have my '88 with me presently to tell you exactly where it is. It's tucked up under the dashboard left of the steering column. It's got full-time 12 Volts and the relay (switched at the shifter OD button) lets that through. Upshot, you can use a toggle switch to bypass the relay. If you have a wiring diagram for your model it'll give you the color coding. I won't be able to give you a better description for a week or so until I get my unit back. Quote Link to comment Share on other sites More sharing options...
Jack - Phoenix Posted April 23, 2007 Share Posted April 23, 2007 I am so glad I found this string - I have the same OD problem but never made the correlation to altitude. However, thinking back it makes sense. We go to Flagstaff (6,000 ft) regularly and it happens every time - I thought it was heat related. More details on how to over-ride the sensor would greatly appreciated. Quote Link to comment Share on other sites More sharing options...
razorback Posted May 6, 2010 Share Posted May 6, 2010 Just drove up to Clovis NM, from Arkansas. When the altitude changed in west TX the OD stopped working - Please advise? jamie travelers rv park. Quote Link to comment Share on other sites More sharing options...
Maineah Posted May 6, 2010 Share Posted May 6, 2010 The sensor is more about engine output then the transmission. At altitude there is less air for the engine to breath so it's output is reduced and the transmission stays in a lower gear to make life easier for the engine. Quote Link to comment Share on other sites More sharing options...
razorback Posted May 6, 2010 Share Posted May 6, 2010 The sensor is more about engine output then the transmission. At altitude there is less air for the engine to breath so it's output is reduced and the transmission stays in a lower gear to make life easier for the engine. When it happened - I heard a bit of ticking sounds from the steering column. Has anyone else heard this??? Or is this a relay problem? stuck in clovis... Quote Link to comment Share on other sites More sharing options...
McShank Posted May 6, 2010 Share Posted May 6, 2010 I travel up into high altitude often and od cuts out as I climb. When I think of my little 2.4L engine trying to push a 6000+ lb. load around I can appreciate that the cut out is there to insure I don't overstrain the engine (more than it is always overstrained). I keep mileage figures every time and I think my mileage has not changed when I've been at 8000' with no od; if I overrode the cut out the rpm's would be too low and my foot would remain all the way to the floor, no od my rpm's are higher but with my foot only half way to the floor. Peak torque on the 2.4 is reached at 3400 rpm's and when at 55 mph in od the engine probably turns close to only 2200 rpm's. That means you are lugging the engine by bypassing od at altitude. Remember you lose 3% of power for every 1000 ft. in altitude and these little engines are undersized already. Jack-Phoenix: I am in New River and lose my od just before the Prescott turn off and get it back coming down the Sunset Point grade into Black Canyon City. Seamus McShank Quote Link to comment Share on other sites More sharing options...
Gulfstream Greg Posted May 9, 2010 Share Posted May 9, 2010 When it happened - I heard a bit of ticking sounds from the steering column. Has anyone else heard this??? Or is this a relay problem? stuck in clovis... Your probably in the fringe altitude where it is on and off and on and off. Just a guess. Quote Link to comment Share on other sites More sharing options...
razorback Posted May 14, 2010 Share Posted May 14, 2010 OD is out and the rig wont start. Maybe related? Changed out the cold start sensor switch as the valve worked fine with voltage. Still not cranking. any apiffanies? Quote Link to comment Share on other sites More sharing options...
Gulfstream Greg Posted May 15, 2010 Share Posted May 15, 2010 The rear end and been changed to a 4:56 from a 4:10.Lee Did the gear change make a worthwhile difference? Quote Link to comment Share on other sites More sharing options...
minicruisin eric Posted October 4, 2010 Share Posted October 4, 2010 As others have said, these usually have an altitude sensor that kicks it out of OD at a certain altitude. When I first got my rig, I would occasionally use OD down hills. However, after further research, I have decided to keep it out of OD all together. The cost of replacing the OD clutches far outweighs the minor mpg savings IMHO. Just one opinion amongst the masses. Quote Link to comment Share on other sites More sharing options...
mini-wini-dan Posted July 18, 2013 Share Posted July 18, 2013 Yes this just happened to me today while driving into south dakota. I heard the ticking and then it started jerking in and out of over drive. Now it won't go in at all and I am near Mount Rushmore. Quote Link to comment Share on other sites More sharing options...
mini-wini-dan Posted July 18, 2013 Share Posted July 18, 2013 yes this just happened to me today while passing into western south dakota. right now I have no over drive functioning. Quote Link to comment Share on other sites More sharing options...
WME Posted July 18, 2013 Share Posted July 18, 2013 Leave it out of OD, most folks never use OD. WME P.S. there is also an altitude cutout than prevents using OD above 4000 ft. Quote Link to comment Share on other sites More sharing options...
waiter Posted July 19, 2013 Share Posted July 19, 2013 Dan, The EFI computer has a pressure sensor that senses altitude. The EFI computer then corrects Injection times based on altitude. ( A lot of older cars use the MAP sensor to do this, they sense the altitude before you start the car.)As a bonus, Toyota also uses the sensor to disable your OD above 1000 meters (about 3,000 ft)JOhn Mc 88 Dolphin 4 Auto Quote Link to comment Share on other sites More sharing options...
douglitas Posted August 12, 2013 Share Posted August 12, 2013 great info! thanks waiter. Quote Link to comment Share on other sites More sharing options...
Chris Mac Posted September 5, 2015 Share Posted September 5, 2015 Thanks for the heads up. I almost had a panic attack. Driving from MD to Park City, Utah in a 1986 Toyota Grandville, 22re engine. Leaving the badlands headed to Mt. Rushmore and start to hear a clicking from the steering column then the transmission slips a few times. As my dad is driving I stumble across this thread and switch the o/d off and the clicking stops and we are on our way. Hopefully it was just the altitude. Update later. Quote Link to comment Share on other sites More sharing options...
Maineah Posted September 6, 2015 Share Posted September 6, 2015 It's more about the engine not having enough guts at altitude that the trans! Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.