artrix Posted July 15, 2007 Share Posted July 15, 2007 hi with a 3 speed auto with an O/D on what would cause the box to drop down a gear at say 100k's (60mph) could it be an electrical / switch related problem. any common faults with these symptoms.? Link to comment Share on other sites More sharing options...
denisb Posted July 15, 2007 Share Posted July 15, 2007 (edited) Did you notice it's more when your pushing down the accelerator? If so, it's possible the kick down switch is a little tempermental or needs adjustment. Assuming we're talking about the W21 model (86-95). Not sure about the newer ones. Denis Edited July 15, 2007 by denisb Link to comment Share on other sites More sharing options...
88pathoffroad Posted July 15, 2007 Share Posted July 15, 2007 A tweeky solenoid pack might have something to do with it, but you have to tear the pan and valvebody off to get to them. Auto trans problems are always a mystery... Link to comment Share on other sites More sharing options...
artrix Posted July 15, 2007 Author Share Posted July 15, 2007 Did you notice it's more when your pushing down the accelerator? If so, it's possible the kick down switch is a little tempermental or needs adjustment. Assuming we're talking about the W21 model (86-95). Not sure about the newer ones. Denis yes its a 1991 model and as far as i can remember the accelerator was not being pushed down when it dropped back. i did notice that i seemed tp be reluctant to go into OD ..im usually a manual transmission driver so i have no knowledge of autos and there odd ways. im in australia and less han half the cars on the road would be autos. i must admit i feel abit out of the loop when i drive it. Link to comment Share on other sites More sharing options...
denisb Posted July 16, 2007 Share Posted July 16, 2007 Auto trannys can be a pain to diagnose. First off it would be better (since we're hearing your troubles via chat forum) if we could get a little more info. Is it happening on a regular basis (daily, weekly, every couple of minutes, etc)? Does it seem to shift hard? When you're driving agressively or not? When was the last tranny flush/oil change? Things like that. Denis Link to comment Share on other sites More sharing options...
artrix Posted July 16, 2007 Author Share Posted July 16, 2007 Auto trannys can be a pain to diagnose. First off it would be better (since we're hearing your troubles via chat forum) if we could get a little more info. Is it happening on a regular basis (daily, weekly, every couple of minutes, etc)? Does it seem to shift hard? When you're driving agressively or not? When was the last tranny flush/oil change? Things like that. Denis hi it doesnt shift hard , and i was not driving aggressively and i believe it was given an oil change less than 1000k's before. the car is one that has just been bought. also what speed does the average trans shift into OD. i have spoken to a fellow that says that the box's shift up and done in direct relationship to the speed and if the speed. Link to comment Share on other sites More sharing options...
Simon Posted July 16, 2007 Share Posted July 16, 2007 Not only speed, but RPM's as well, not to mention throttle position. Are you saying the RPM's drop down after being in OD? Does it only drop about 500rpms? If so, it's your torque converter locking up. Perfectly normal, and nothing to worry about. If you're saying it's downshifting out of OD often (RPM's going up) then it could just be that it can't maintain speed in OD, and has to downshift to do so. They shift a lot, as the engine (assuming you've got the VG30 engine) is underpowered. Link to comment Share on other sites More sharing options...
artrix Posted July 16, 2007 Author Share Posted July 16, 2007 (edited) Not only speed, but RPM's as well, not to mention throttle position.Are you saying the RPM's drop down after being in OD? Does it only drop about 500rpms? If so, it's your torque converter locking up. Perfectly normal, and nothing to worry about. If you're saying it's downshifting out of OD often (RPM's going up) then it could just be that it can't maintain speed in OD, and has to downshift to do so. They shift a lot, as the engine (assuming you've got the VG30 engine) is underpowered. when the OD comes in it drops the by 500 rpm. its at 60 mph that it dropped back and stayed there. it also seems not to want to go into OD sometimes, tonight i was driving at 50-55mph and it was still in 3rd, surely it should have slipped up into OD(4th) by then. the trouble with me is that i have zero experience with autos so when i read some of the info on this site i have no idea what most are talking about. im in australia and i would think that manuals outnumber autos here. we like to drive the car not just steer it Edited July 16, 2007 by artrix Link to comment Share on other sites More sharing options...
Simon Posted July 16, 2007 Share Posted July 16, 2007 No....if it only drops by 500rpms, that's the torque converter locking up. The OD will drop the revs much further than that from 3rd gear. I believe it's over 1k. Sounds to me like the torque converter is not locking/unlocking as it should. At 50-55mph, what were your RPM's at? Link to comment Share on other sites More sharing options...
artrix Posted July 17, 2007 Author Share Posted July 17, 2007 (edited) at 50-55 i believe rpms were around 3250 -3500.....as for the OD drop to 3rd 1000 rpms is about right now that you mention it. bloody thing at the moment just seems reluctant to change into OD Edited July 17, 2007 by artrix Link to comment Share on other sites More sharing options...
denisb Posted July 17, 2007 Share Posted July 17, 2007 3500 rpms seem a little high in O/D at 55mph, but like Simon said, when the torque converter locks up on the highway it almost feels like another gear change and it will unlock as soon as you press the accelerator the least little bit. Now if the kickdown switch, tranny computer or your shift solnoid were bad, it might not shift into O/D a soon as it should. You would probably get a hard shift when it would shift tho. You can try reseting the tranny ECU to see if it helps, never know sometimes those Gremlins are sneaking around in there. I beleive it's located in the left rear panel next to the speaker. You mentioned the oil was changed.....you did mean the tranny oil right? Oh and how many miles/Km on the rig. Link to comment Share on other sites More sharing options...
88pathoffroad Posted July 17, 2007 Share Posted July 17, 2007 BTW: the "kickdown switch" is the throttle position sensor/switch. It serves two purposes, as a on/off idle switch AND a throttle position sensor. Being mal-adjusted can cause trans shifting problems at times. Link to comment Share on other sites More sharing options...
artrix Posted July 17, 2007 Author Share Posted July 17, 2007 3500 rpms seem a little high in O/D at 55mph, but like Simon said, when the torque converter locks up on the highway it almost feels like another gear change and it will unlock as soon as you press the accelerator the least little bit. Now if the kickdown switch, tranny computer or your shift solnoid were bad, it might not shift into O/D a soon as it should. You would probably get a hard shift when it would shift tho. You can try reseting the tranny ECU to see if it helps, never know sometimes those Gremlins are sneaking around in there. I beleive it's located in the left rear panel next to the speaker. You mentioned the oil was changed.....you did mean the tranny oil right? Oh and how many miles/Km on the rig. the car has 160,000 kilometres (100,000 miles) and as far as im aware they changed all the oils less than 600 miles ago. how do you reset the tranny ecu? it all changes ok around town it just seems to be a problem firstly getting intoOD then staying there. thanx for all your assistance guys, im sure i sound like a dope but as i said i know nothing about autos. have rebuilt diesel engines so im not in capable of working on the thing just have no idea where to start. Link to comment Share on other sites More sharing options...
denisb Posted July 17, 2007 Share Posted July 17, 2007 The easiest way is probably to disconnect the battery terminal and keep the brakes pressed for a couple of secs to make sure all voltage has been drained. The ECU should then reprogram itself as your driving. The rig might run a little crapy for a couple of miles while everything resets. As 88 pointed out the Kickdown switch is a throtle position switch. It can be adjusted and if it's faulty it could be seeing the throtle as being "mashed" or pushed down causing the tranny to have a higher shift patern. This is why I was saying you would probably get a harder shift. To absolutely positively make sure that the O/D is not engaging and that it's not a torque lock up issue, try this. When it seems to either drop down or not go into O/D, hit your O/D button on the stick and see if it actually drops a gear. If it does it sounds lick a lock up issue. If it doesn't, then your O/D definately doesn't engage. Denis Link to comment Share on other sites More sharing options...
artrix Posted July 17, 2007 Author Share Posted July 17, 2007 (edited) The easiest way is probably to disconnect the battery terminal and keep the brakes pressed for a couple of secs to make sure all voltage has been drained. The ECU should then reprogram itself as your driving. The rig might run a little crapy for a couple of miles while everything resets. As 88 pointed out the Kickdown switch is a throtle position switch. It can be adjusted and if it's faulty it could be seeing the throtle as being "mashed" or pushed down causing the tranny to have a higher shift patern. This is why I was saying you would probably get a harder shift. To absolutely positively make sure that the O/D is not engaging and that it's not a torque lock up issue, try this. When it seems to either drop down or not go into O/D, hit your O/D button on the stick and see if it actually drops a gear. If it does it sounds lick a lock up issue. If it doesn't, then your O/D definately doesn't engage. Denis ok here goes just did a test drive after i disconected the battery for over an hour to try and reset the ecu. no change i got onto the motorway and got up to110k's (65mph) and it didnt go into OD. tried to switch the OD button on off and on at that speed and nothing happened. i then got home and went thru the self diagnosis proceedure that i believe 88 posted. i got 1 long flash followed by 10 short, it repeated this series 1 long 10 short. at first i got exited and thought i had a fault readingfor ''REVOLUTION SENSOR CIRCUIT IS SHORT CIRCUITED or DISCONECTED. that was short lived as i re-read the directions and it looks like what i was seeing was a confirmation that all circuits are ok! thats if im interpreting the self diagnostic directions correctly. just looked at another post regards sel diagnostics , it read the OD light flickered ? i was assuming it was the light on the switch that has HOLD A/T POWER on it ......... is that the correct one to be looking at. on the sheet i copied it readsPOWER SHIFT LAMP i assumed that to be the HOLD A/T POWER switch.... if im starting to frustrate any one with my lack of knowledge please be patient im not really a pumpkin head. bugger bugger bugger.............................this is all getting very frustrating. any more advice would be as usual gratefully recieved. Edited July 17, 2007 by artrix Link to comment Share on other sites More sharing options...
denisb Posted July 17, 2007 Share Posted July 17, 2007 The light on the botton is the right one and it does look like the O/D is not engaging. The switch you tare talking about, did you try it in both position? It also changes the shift points as it is used for when more power is needed such as towing. At this point I'm more or less trying to brainstorm, as it is pretty hard to do a lot more troubleshooting withoout actually being there. Link to comment Share on other sites More sharing options...
denisb Posted July 17, 2007 Share Posted July 17, 2007 I just got another brainstorm.......you're from Australia right? I've always wanted to visit Australia. I'm only the cost of a plane ticket away from test driving your Pathy to trouble shoot the sympthoms . Sounds like a win win situation to me. Denis Link to comment Share on other sites More sharing options...
artrix Posted July 17, 2007 Author Share Posted July 17, 2007 (edited) I just got another brainstorm.......you're from Australia right? I've always wanted to visit Australia. I'm only the cost of a plane ticket away from test driving your Pathy to trouble shoot the sympthoms . Sounds like a win win situation to me. Denis good point there denis , it would be easier if we could have an expert here , i'll send my private jet immediately, start packing your bags.. so would you agree that the self diagnosis flashes i saw give an all ok signal? Edited July 17, 2007 by artrix Link to comment Share on other sites More sharing options...
denisb Posted July 18, 2007 Share Posted July 18, 2007 Sorry it took some time to reply I was packing my suitcase....what kind of weather are you having down there so I know what to pack If you saw 1 long and 10 short, my manual says it's an all ok code. Now all ok does not mean you don't have a problem, it just means you don't have a proble that the ECU is seeing. I've got a someone's scaned copy of the shop manual, I'll see how big the Auto Tranny section is. I might be able to seend it to you, it has a lot of trouble shooting info in it. I won't be able to check until tomorrow when I get to work, but If I've got it, I'll get your e-mail address and send it to you. Denis Link to comment Share on other sites More sharing options...
artrix Posted July 18, 2007 Author Share Posted July 18, 2007 Sorry it took some time to reply I was packing my suitcase....what kind of weather are you having down there so I know what to pack If you saw 1 long and 10 short, my manual says it's an all ok code. Now all ok does not mean you don't have a problem, it just means you don't have a proble that the ECU is seeing. I've got a someone's scaned copy of the shop manual, I'll see how big the Auto Tranny section is. I might be able to seend it to you, it has a lot of trouble shooting info in it. I won't be able to check until tomorrow when I get to work, but If I've got it, I'll get your e-mail address and send it to you. Denis thanks for that mate i have sent you a privae message with my email address let me know if it didnt get thru. as for the weather its winter here at the moment but its between 18-22 degress centigrade during the day, have no idea what that is in farenhieght. i imagine the weather is like florida in winter. too cold for us to swim in the ocean but you do see a lot of carzy tourists in the surf. Link to comment Share on other sites More sharing options...
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