Balmer Posted August 24, 2009 Share Posted August 24, 2009 My E-AT switch keeps coming on (power position) by itself. I find this somewhat confusing. It's a rocker switch - not a momentary switch, . The switch physically stays in the "auto" position, but often when I'm starting off from a light or even a slow rolling speed, the light comes on indicating that the E-AT has switched to "power" position. The light is accurate - the trans. DOES switch into power mode - which I can't stand. Would this be caused by the switch itself or another part of the E-AT system. Can I simply wire the switch directly so that it MUST stay in the auto position? Is there another way to by-pass the "power" option on the auto trans? Link to comment Share on other sites More sharing options...
Simon Posted August 24, 2009 Share Posted August 24, 2009 You're hitting the throttle too hard. It'll automatically kick into "Power" mode if you hit the throttle hard. Some folks have reported it also does it if you "double kick" the throttle. Link to comment Share on other sites More sharing options...
adamzan Posted August 24, 2009 Share Posted August 24, 2009 You're hitting the throttle too hard. It'll automatically kick into "Power" mode if you hit the throttle hard. Some folks have reported it also does it if you "double kick" the throttle. X2 Also that power light can blink indicating issues with the trans that are electrical so don't get rid of it. Link to comment Share on other sites More sharing options...
94extreme Posted August 24, 2009 Share Posted August 24, 2009 he said that it does it in slow speed to.. so, if you're NOT punching it then run the diagnostics mode on your ECU that's appropriate for the transmission diagnoses. Link to comment Share on other sites More sharing options...
Kittamaru Posted August 24, 2009 Share Posted August 24, 2009 It does indeed activate Power mode if you double tap the pedal - it's in preparation for a need of emergency power, a very nice feature that's incredibly useful for prepping the engine for short-run highway on ramps - it kicks down a gear or two but doesn't rev up right away, allowing you to rev up quickly (but gradually) rather than it simply jumping 2k RPM Link to comment Share on other sites More sharing options...
Indigent Posted August 24, 2009 Share Posted August 24, 2009 I would run the transmission diagnostic check. I suspect that your throttle position swith might be bad. It is not monitored by the ECU, but will show up on the TCU check. Even if the TCU check passes, it could still be bad, because the TCU check doesn't measure the resistance at each 1/8 position. The only way to really check the TPS is to get a multimeter and measure the resistance at each 1/8 section of stroke. Link to comment Share on other sites More sharing options...
Balmer Posted August 25, 2009 Author Share Posted August 25, 2009 Thanks for the advice guys. Since, in my opinion, the throtle CAN'T be punched too hard, is there an easy by-pass? I would be much happier without this option despite everyone's high opinion of it. Link to comment Share on other sites More sharing options...
Kittamaru Posted August 25, 2009 Share Posted August 25, 2009 Why don't you like the power mode is my first question - it's quite useful, and all it really does is twofold: A) Engine revs higher for longer before transmission shifts Transmission downshifts sooner to give more torque Link to comment Share on other sites More sharing options...
Balmer Posted August 25, 2009 Author Share Posted August 25, 2009 I don't like it because my rig is a 90% dedicated trail rig. THE "POWER" OPTION SUCKS OFF-ROAD!!! Some may debate this but I find it too be a total PITA to have my trans shifting to an unrealisticly low gear when the power I need to smoothly get over rocks is found in the gear I'm in. I could go on and on about the situations in which this option is a disadvantage, but if you've wheeled your rig HARD in a variety of situations, I have a hard time believing that you've found the "power" option to be helpfull. I can see it on the highway and other road driving conditions but not for the kind of wheelin' I do! I love having an auto since it is way better in mud and snow as well as other terrain due to the lack of a "pause" in shifting as with a standard. In "auto" position the trans shifts just how I like it. We can debate the merrits (or lack thereof) of this system, but the fact is I DON"T WANT IT! So, again I ask... does anyone know how to by-pass this option. Link to comment Share on other sites More sharing options...
adamzan Posted August 25, 2009 Share Posted August 25, 2009 Try unplugging the switch maybe it will disable the circuit? Link to comment Share on other sites More sharing options...
Indigent Posted August 25, 2009 Share Posted August 25, 2009 This doesn't particularly help, but the Terranos have a third position in the switch called Hold. It prevents the tranny from entering power mode. Since it is the exact same tranny, I doubt that they made any changes in the TCU program. It may well just be a wiring thing, who knows. I am curious now, and I am going to look into the schematics and see. Link to comment Share on other sites More sharing options...
headpeace Posted August 25, 2009 Share Posted August 25, 2009 I know when my power mode kicks in automatically and unwanted I just tap the brake and it goes off. Maybe if you just apply a small amount of break it would keep it from coming on? Link to comment Share on other sites More sharing options...
Balmer Posted August 25, 2009 Author Share Posted August 25, 2009 This doesn't particularly help, but the Terranos have a third position in the switch called Hold. It prevents the tranny from entering power mode. Since it is the exact same tranny, I doubt that they made any changes in the TCU program. It may well just be a wiring thing, who knows. I am curious now, and I am going to look into the schematics and see. Cool man, you rock... I hope you come up with something. Link to comment Share on other sites More sharing options...
Balmer Posted August 25, 2009 Author Share Posted August 25, 2009 I know when my power mode kicks in automatically and unwanted I just tap the brake and it goes off. Maybe if you just apply a small amount of break it would keep it from coming on? Mine doesn't go back into "auto" mode unless I manually throw the switch, it just stays in "power" mode regardless of how I drive it. Link to comment Share on other sites More sharing options...
headpeace Posted August 25, 2009 Share Posted August 25, 2009 Oh, yeh that blows Link to comment Share on other sites More sharing options...
TerranoNZ Posted August 25, 2009 Share Posted August 25, 2009 This doesn't particularly help, but the Terranos have a third position in the switch called Hold. It prevents the tranny from entering power mode. Since it is the exact same tranny, I doubt that they made any changes in the TCU program. It may well just be a wiring thing, who knows. I am curious now, and I am going to look into the schematics and see. I thought "hold" would hold the auto in one gear I'll check the next time mine runs I'm not a fan of that power mode, to me it shifts faster normally. When in power mode it over revs, it's no longer making power, just revving. Each to their own though Link to comment Share on other sites More sharing options...
Balmer Posted August 25, 2009 Author Share Posted August 25, 2009 "I'm not a fan of that power mode, to me it shifts faster normally. When in power mode it over revs, it's no longer making power, just revving. Each to their own though" My sentiments exactly. Link to comment Share on other sites More sharing options...
GrimGreg Posted August 26, 2009 Share Posted August 26, 2009 I'll use it in power mode offroad for climbs, don't want it to shift normally and bog down half way up and lose momentum (been there, wasn't fun). Link to comment Share on other sites More sharing options...
Kittamaru Posted August 26, 2009 Share Posted August 26, 2009 (edited) I don't like it because my rig is a 90% dedicated trail rig. THE "POWER" OPTION SUCKS OFF-ROAD!!! Some may debate this but I find it too be a total PITA to have my trans shifting to an unrealisticly low gear when the power I need to smoothly get over rocks is found in the gear I'm in. I could go on and on about the situations in which this option is a disadvantage, but if you've wheeled your rig HARD in a variety of situations, I have a hard time believing that you've found the "power" option to be helpfull. I can see it on the highway and other road driving conditions but not for the kind of wheelin' I do! I love having an auto since it is way better in mud and snow as well as other terrain due to the lack of a "pause" in shifting as with a standard. In "auto" position the trans shifts just how I like it. We can debate the merrits (or lack thereof) of this system, but the fact is I DON"T WANT IT! So, again I ask... does anyone know how to by-pass this option. Woah, chill out cowboy - my rig is 99% on road, and yes, power option is VERY useful for jumping on highways with short on ramps. I can imagine it'd suck for off road use though, since torque control is what it's all about. As for over-revving - mine seems to shift at the absolute apex of it's rev - if I manually control the gearing (via the shifter) I can find the "sweet spot" from which to shift from 1st to 2nd and 2nd to 3rd - it's great for, as I said, short ramp highway entrances, as I can pull 0-60 far faster than I could otherwise, though with the result of higher RPM, higher gas consumption, and a little smoke from the tailpipe as oil blows past the rings at such high pressures in the engine. However, if it's either blow a little white smoke or be rear ended by an 18 wheeler doin 30 mph over the speed limit, I'll take the former Power mode seems to use the same shift techniques... it's cool and such. However, in normal mode, I get FAR better mileage, and I shift much sooner. It's great for everyday driving - off road, I don't imagine either one would be particularly good... which is why most people prefer manuals off road, right? Edited August 26, 2009 by Kittamaru Link to comment Share on other sites More sharing options...
OldSlowReliable Posted August 26, 2009 Share Posted August 26, 2009 I just always flip it on for offroad.....It really helps for not getting bogged down at the top of climbs on dunes or deep rutted hill climbs in forests.....Sure, my engine is yelling pretty loud, but otherwise it shifts to run at like 1500rpm which is not too great for the top of a 75ft dune.... Link to comment Share on other sites More sharing options...
Balmer Posted August 27, 2009 Author Share Posted August 27, 2009 Again... I'm not trying to offend anyone who loves their E-AT option. I just want to know how to by-pass it. Link to comment Share on other sites More sharing options...
OldSlowReliable Posted August 27, 2009 Share Posted August 27, 2009 Again... I'm not trying to offend anyone who loves their E-AT option. I just want to know how to by-pass it. Be lighter on your gas pedal? Otherwise, would it be possible to just disconnect the switch? Maybe that switch itself is required to make it happen, cause when it does it auto, the light comes on...idk Link to comment Share on other sites More sharing options...
Indigent Posted August 27, 2009 Share Posted August 27, 2009 I thought "hold" would hold the auto in one gear I'll check the next time mine runs I'm not a fan of that power mode, to me it shifts faster normally. When in power mode it over revs, it's no longer making power, just revving. Each to their own though Mine was a TD27T, and I remember it being able to shift normally when in hold mode both up and down, but when I stomped on the pedal, it would not go into power mode. Link to comment Share on other sites More sharing options...
mitsu Posted September 11, 2009 Share Posted September 11, 2009 as far as i know with the power switch it lets the gear change at a higher RPM than in the auto mode, normally when mine comes on i jus use the kinkdown switch to come out of it, but i has happened to me when i move off and when first gear revs above 2500rpm the light will come on and it well rev to about 3500 and it will change Link to comment Share on other sites More sharing options...
Indigent Posted September 11, 2009 Share Posted September 11, 2009 Just a quick update. I took the TCU out of my junk pathfinder and pulled the eprom out and disassembled the code. There is a specific routine that monitors the Throttle Position Switch, and once it reaches a certain amount, it activates the Power Mode routine. On the 90-93 WD21's (there are 2 additional wires on the 94-95 for the dimmer illumination) there are 4 wires going from the TCU to the switch. Two are for the light, and two are for the intentional power mode side of the switch. When the switch is in the Auto position it is essentially open, therefore there is no way to "easily" modify these trucks to have the Hold function of the JDM model. Could someone with an auto Terrano chime in on how many wires are on that switch? My suspiscion is that there is at least one extra wire in the switch to specifically activate a Hold Mode routine in the TCU. Link to comment Share on other sites More sharing options...
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