Does anyone have an answer to this problem? I have just recently bought a MR2 hyd pump (2001-2005 with integrated ECU) and am having the exact same problem. The pump will turn on and run fine, but it runs backward. This is the third pump I have tried( peugeot 307, subaru xt6 and MR2) and all three have had something wrong with them. The 307 runs at what seems about 20 rpm and puts out zero pressure, the xt6 I cannot even get to turn on (although I haven't really tried anything more than just hooking a pos and neg leads to the big terminals) and the MR2 runs backward. I really would like to figure out the MR2 because it came with a really nice mounting bracket that fit perfectly and I have the fittings for the hyd lines already. Thanks in advance.
Power Steering using Toyota MR2 EHPS pump
Many EV conversions have to deal with Power Steering decision. If you decided to keep PS and looking how to drive PS pump, consider this all-in-one solution brought to you by Toyota engineers. Toyota MR2 has EHPS ( Electric Hydraulic Power Steering ) in which pump is driven by its own electric motor instead of pulley hanging off the main engine like most ICE cars do. First generation of MR2 had separate fluid tank, motor/pump assembly and controller, some EVers took motor/pump and wired it directly to 12V or via various switching circuits designed to keep the pump off while driving straight or at high speed to save power.
However, 3rd generation of MR2 also called Spyder has a single pump assembly combining motor, pump, fluid tank and controller, making it very attractive option for EV community.
To the best of my knowledge you are looking for 2000-2005 ( maybe some other years, I'm not sure ) EHPS pump from Toyota MR2 Spyder, call your local junk yards or check this one online http://car-part.com . The pump looks like this:
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To wire it use schematics below. If you don't have proper harnesses you can either solder directly or create your own connectors for each pin. I personally created connectors and then filled harnesses with caulk to keep wires in place. It can be removed later if needed.
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Although 50 Amp relay is stated, I couldn't find one so I used typical 40 Amp automotive relay, my testing shows that it doesn't actually reach 50 Amp current anyway.
You can wire VSS signal from your car to make the pump turn itself off at higher speeds, but I couldn't manage that because my Miata has unusual VSS signal. Even without VSS, the pump runs idle at 4 Amps until you actually turn the steering wheel, so the power wasted is very minimal.
You'd have to find a way to connect PS Pressure line from the pump to your car's rack and return line from the rack back to the pump. Return line is easy, just use 3/8 hose and clamps. As for pressure line, if you are lucky you can fit one from other Toyota models, if not, you can make custom one from separately purchased fittings and the pressure hose, I have seen those on Ebay and online shops like this one http://www.summitracing.com/
Hope this helps, feel free to update this Wiki with more details, my main goal was to publish schematics and wiring, I am not very good with hydraulics, maybe someone can add details on making custom pressure hose.
Here are the Toyota part#'s for the electrical Connectors: These part#'s get the Plastic part only, The metal pin wiring parts are sold separately. Maybe someone can add the part#'s for those.
Part#'s Large connector 90980-12068
Middle connector 90980-10897
Small end connector 90980-10942
There are two part numbers for the wiring. They come with the plugs, rubber seals, & about 6 inches of wire. At $6.55/ea they aren't cheap for what you get, but they are made to fit.
Three pigtails for the small & middle connectors P/N: 82998-12440
Two pigtails for the large connector P/N: 82998-12500
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However, 3rd generation of MR2 also called Spyder has a single pump assembly combining motor, pump, fluid tank and controller, making it very attractive option for EV community.
To the best of my knowledge you are looking for 2000-2005 ( maybe some other years, I'm not sure ) EHPS pump from Toyota MR2 Spyder, call your local junk yards or check this one online http://car-part.com . The pump looks like this:
To wire it use schematics below. If you don't have proper harnesses you can either solder directly or create your own connectors for each pin. I personally created connectors and then filled harnesses with caulk to keep wires in place. It can be removed later if needed.
Although 50 Amp relay is stated, I couldn't find one so I used typical 40 Amp automotive relay, my testing shows that it doesn't actually reach 50 Amp current anyway.
You can wire VSS signal from your car to make the pump turn itself off at higher speeds, but I couldn't manage that because my Miata has unusual VSS signal. Even without VSS, the pump runs idle at 4 Amps until you actually turn the steering wheel, so the power wasted is very minimal.
You'd have to find a way to connect PS Pressure line from the pump to your car's rack and return line from the rack back to the pump. Return line is easy, just use 3/8 hose and clamps. As for pressure line, if you are lucky you can fit one from other Toyota models, if not, you can make custom one from separately purchased fittings and the pressure hose, I have seen those on Ebay and online shops like this one http://www.summitracing.com/
Hope this helps, feel free to update this Wiki with more details, my main goal was to publish schematics and wiring, I am not very good with hydraulics, maybe someone can add details on making custom pressure hose.
Here are the Toyota part#'s for the electrical Connectors: These part#'s get the Plastic part only, The metal pin wiring parts are sold separately. Maybe someone can add the part#'s for those.
Part#'s Large connector 90980-12068
Middle connector 90980-10897
Small end connector 90980-10942
There are two part numbers for the wiring. They come with the plugs, rubber seals, & about 6 inches of wire. At $6.55/ea they aren't cheap for what you get, but they are made to fit.
Three pigtails for the small & middle connectors P/N: 82998-12440
Two pigtails for the large connector P/N: 82998-12500
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Thanks for the reply. I can get the pump to run, that is not the problem. The problem is that it runs backward. It pumps air instead of fluid. I have hooked the 12vdc (50 amp) pos and neg to the fat pins like in the picture on page one of this thread. Neg being the farthest pin outboard. The middle connector(6 pin) I have +12vdc going to pin 5, lower right corner. And the end connector(4 pin) I have +12vdc going to the upper right corner, pin 1. If +12vdc is connected directly to these pins, the internal relay kicks on and the pump runs for about a 1/2 second, then stops then runs backward at what I assume is full power. If I try to wire it up exactly as depicted in the picture with an external relay, it will not run at all. The voltage after the main (50 amp) relay, pin 86/coil, drops to about 8 volts and this is not enough to get the internal relay(inside the pump connected at pin 5) to switch on.
I opened up the case of the ECU on the pump and found that pin 1 on the outside 4 pin connector was extremely corroded. In fact it fell apart when I tried to clean it. So I soldered in a new pin. Continuity checks and the pump does the same thing after being wired up again. HB0517 said that he has had the exact same problem, but so far no response from a PM I sent him. Has anyone else had a similar problem with the 2001 Spyder MR2 pump? There is no other corrosion inside the pump that I could see.
So far this hyd system has been nothing but frustration for me.
Any help is greatly appreciated. Thanks.
I opened up the case of the ECU on the pump and found that pin 1 on the outside 4 pin connector was extremely corroded. In fact it fell apart when I tried to clean it. So I soldered in a new pin. Continuity checks and the pump does the same thing after being wired up again. HB0517 said that he has had the exact same problem, but so far no response from a PM I sent him. Has anyone else had a similar problem with the 2001 Spyder MR2 pump? There is no other corrosion inside the pump that I could see.
So far this hyd system has been nothing but frustration for me.
Any help is greatly appreciated. Thanks.
41 - 60 of 73 Posts
