Pwr Steering with an SMC?

Tylerfishsmith · 10-24-2006, 02:00 PM

Anyone ever figured out how to use the power steering without the factory ecu? Finishing up an install with a SMC and having a bit of trouble here. I would imagine it would be the same solution regardless of what type of aftermarket engine management was used. Any thoughts would be appreciated.

Thanks...Tyler

Enthalpy · 10-29-2006, 08:18 PM

The P/S is actually quite simple. There is one output the stock ECU has that deals with the P/S. Otherwise, the P/S has its own ECU.

That one output prevents the power steering system from draining the battery when the engine isn't turning. It's a pull-to-ground lead.

Most map it to positive RPM, but I don't. I map it to voltage > ~12.3 volts. That way, if your alternator craps itself while driving, the battery lasts longer.

With the Autronic (depending on which you have), you should be able to setup one pull-to-ground output like this.

If you only have pull-to-high outputs left, no worries. You can wire a relay to pull that P/S lead to ground when the relay's coil sees high power from the EMS. The other coil side would be grounded, of course. Make sure you use a relay with enough coil resistance so as to avoid blowing the Autronic output.

Tylerfishsmith · 10-30-2006, 08:48 AM

There are two wires from the stock ecu. One labeled PS and the other is PCST I believe. On the steering ecu they are labeled EFI and IDUP. I ran the PS or EFI wire to a yellow/black ignition on hot wire from the efi main relay. The other wire is capped. I have heard others doing it this way. When key is on pwr is fed to steering ecu. IDUP wire I assume tells the stock ecu when pump is on to adjust for the extra load, not sure though. As the autronic will automatically adjust any idle changes I felt this wire was not needed. Any extra thoughts on this will be helpful.

Enthalpy · 10-30-2006, 09:59 AM

Wow, I will have to revisit the wiring diagrams. I made a mistake. My apologies.

You are right, the Autronic will compensate its idle, but the feedback loop might take too long. It's worth playing with.

If it does die, you could use an A/C idle up valve to give the engine a burst of air as the P/S engages. I would have to look into how to wire that up and what signals come from the P/S ECU to the motor.

Tylerfishsmith · 10-30-2006, 10:10 AM

I am not saying I am 100% right on this. It just made sense to me. I have heard that this is how others make it work on their cars. Keep the thought machine running as I would like to be sure before I finish my wiring.

Thanks for your input...Tyler

Enthalpy · 10-31-2006, 01:22 AM

Well, there's one way to know for sure. Fire the thing up and see if you can replicate what's going on.

Tylerfishsmith · 10-31-2006, 08:22 AM

I will have to wait until I get my smc back. Having it checked out by a dealer to make sure everything is ok. I had a short several years ago and have not messed with car since. Want to make sure the ECU is OK before I try and start again and chase gremlins somewhere else. Tuning will be quite daunting for me. Cannot find any base maps for this setup. Will have to try and figure out on my own. Oh yea...this the first time I have ever tried to tune. Will take it very slow for sure.

Enthalpy · 10-31-2006, 10:52 AM

The Autronic has one of the absolute best interfaces for tuning that I have seen. It's not the simplest, but it is one of the best-organized. The Autronic is one of the few true speed-density EMSes around. Unfortunately, I have only tuned Subarus on them, so I don't have a base map for you. I can help you out with tuning, if you want.

Tylerfishsmith · 10-31-2006, 11:12 AM

I really appreciate that. I will touch base with you later when I get SMC back and am ready to start car. I wish there was a way to interface the laptop output live online. Car could be tuned in cyberspace by someone like yourself who is experienced. That is walk me through it live. MMMM...need to think about this. A live public forum tuning a car. Having one of those Eureaka moments...I am sure it has already been done somewhere. Well, thanks again...will get back in touch later.

Tylerfishsmith · 10-31-2006, 11:14 AM

Am going to wire in LC-1 instead of stock O2 this weekend. That way I can use the autotune feature. This is what really drew me to the SMC. Know anyone who has done this? Getting conflicting info from Innovate message board.

Enthalpy · 10-31-2006, 03:54 PM

I have tried the "remote tuning" thing. It doesn't work that well. A big part of the tuning is listening to the engine. The engine will tell you quite a bit of what you need to know, and if you aren't physically there, you don't get that quality of tuning.

Autronic is one of many EMSes that does autotune. The Nemesis and AEM EMS does autotune as well.

There's a trick with Autotune. Autronic tried to mandate you use their exhaust analyzer. People have gotten the LM-1 to work just fine with Autronic. You won't be able to use the Dyno Dynamics integration (which is software that communicates with the dyno to autotune).

There was a website on the LM-1 and Autronic out there. I have always used the dyno wideband, so it's never come up with me.

My email is damon.becker (at) comcast (dot) net. Drop me a line if you want help. For some reason, my email notification isn't working. I'll keep checking back on this thread, though.

Tylerfishsmith · 11-15-2006, 03:05 PM

Now I am wrong on the pwr steering. Was looking at it again last night and noticed that the two wires from the steering ecu are out to engine ecu. Good thing I didn't pwr it up that way. I believe they are telling engine ecu when and how strong the steering pump is running so the load can be compensated for. The steering pump I believe to get it's signal via speed sensor in tranny. I am not going to pwr anything up and see how it works. Now I just need to pwr water injection pump and IC fan. Not sure where to pull pwr from. Thinking about the same leg as injectors and fuel pump. Think that will be OK. Have a 30amp inline fuse w/relay here. Thinking injection pump and spal fan should not overload. What do you think?

Enthalpy · 11-15-2006, 03:27 PM

You could test this easily enough. Fire up the key (engine off) and see if there's voltage between the probes and ground. If not, manually ground them. If the pump kicks on, then there's your answer. One is for idle control, and the other is for P/S activation. You would only be able to use one, unless you use the other for an idle-up valve activation, akin to the A/C idle-up function.

As for pulling power, size the electrical loads you are imposing. The fan and pump might not be trivial. You might have to pull another source off that battery. The last thing you want to do is pop the fuel pump when you simultaneously start up 3 different motors (fuel pump, fan, W/I pump).

When you start up a pump, it draws roughly 2X the power it does under steady-state.

For my I/C, engine lid and W/I pump setup, I pulled a fused switched high (using my own relay) from the battery.

10-24-2006, 02:00 PM	#1 (permalink)
Tylerfishsmith No Skills Join Date: Sep 2006 Location: Gulf Breeze, FL Posts: 51 Thanks: 0 Thanked 1 Time in 1 Post My Google Map iTrader Rating: (0/0% )	Pwr Steering with an SMC? Anyone ever figured out how to use the power steering without the factory ecu? Finishing up an install with a SMC and having a bit of trouble here. I would imagine it would be the same solution regardless of what type of aftermarket engine management was used. Any thoughts would be appreciated. Thanks...Tyler

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10-29-2006, 08:18 PM	#2 (permalink)
Enthalpy EMS Harmonizer Join Date: Feb 2006 Location: Denver, CO Posts: 1,226 Thanks: 8 Thanked 55 Times in 43 Posts My Google Map iTrader Rating: (2/100% )	The P/S is actually quite simple. There is one output the stock ECU has that deals with the P/S. Otherwise, the P/S has its own ECU. That one output prevents the power steering system from draining the battery when the engine isn't turning. It's a pull-to-ground lead. Most map it to positive RPM, but I don't. I map it to voltage > ~12.3 volts. That way, if your alternator craps itself while driving, the battery lasts longer. With the Autronic (depending on which you have), you should be able to setup one pull-to-ground output like this. If you only have pull-to-high outputs left, no worries. You can wire a relay to pull that P/S lead to ground when the relay's coil sees high power from the EMS. The other coil side would be grounded, of course. Make sure you use a relay with enough coil resistance so as to avoid blowing the Autronic output.

10-30-2006, 08:48 AM	#3 (permalink)
Tylerfishsmith No Skills Join Date: Sep 2006 Location: Gulf Breeze, FL Posts: 51 Thanks: 0 Thanked 1 Time in 1 Post My Google Map iTrader Rating: (0/0% )	There are two wires from the stock ecu. One labeled PS and the other is PCST I believe. On the steering ecu they are labeled EFI and IDUP. I ran the PS or EFI wire to a yellow/black ignition on hot wire from the efi main relay. The other wire is capped. I have heard others doing it this way. When key is on pwr is fed to steering ecu. IDUP wire I assume tells the stock ecu when pump is on to adjust for the extra load, not sure though. As the autronic will automatically adjust any idle changes I felt this wire was not needed. Any extra thoughts on this will be helpful.

10-30-2006, 09:59 AM	#4 (permalink)
Enthalpy EMS Harmonizer Join Date: Feb 2006 Location: Denver, CO Posts: 1,226 Thanks: 8 Thanked 55 Times in 43 Posts My Google Map iTrader Rating: (2/100% )	Wow, I will have to revisit the wiring diagrams. I made a mistake. My apologies. You are right, the Autronic will compensate its idle, but the feedback loop might take too long. It's worth playing with. If it does die, you could use an A/C idle up valve to give the engine a burst of air as the P/S engages. I would have to look into how to wire that up and what signals come from the P/S ECU to the motor.

10-30-2006, 10:10 AM	#5 (permalink)
Tylerfishsmith No Skills Join Date: Sep 2006 Location: Gulf Breeze, FL Posts: 51 Thanks: 0 Thanked 1 Time in 1 Post My Google Map iTrader Rating: (0/0% )	I am not saying I am 100% right on this. It just made sense to me. I have heard that this is how others make it work on their cars. Keep the thought machine running as I would like to be sure before I finish my wiring. Thanks for your input...Tyler

10-31-2006, 01:22 AM	#6 (permalink)
Enthalpy EMS Harmonizer Join Date: Feb 2006 Location: Denver, CO Posts: 1,226 Thanks: 8 Thanked 55 Times in 43 Posts My Google Map iTrader Rating: (2/100% )	Well, there's one way to know for sure. Fire the thing up and see if you can replicate what's going on.

10-31-2006, 08:22 AM	#7 (permalink)
Tylerfishsmith No Skills Join Date: Sep 2006 Location: Gulf Breeze, FL Posts: 51 Thanks: 0 Thanked 1 Time in 1 Post My Google Map iTrader Rating: (0/0% )	I will have to wait until I get my smc back. Having it checked out by a dealer to make sure everything is ok. I had a short several years ago and have not messed with car since. Want to make sure the ECU is OK before I try and start again and chase gremlins somewhere else. Tuning will be quite daunting for me. Cannot find any base maps for this setup. Will have to try and figure out on my own. Oh yea...this the first time I have ever tried to tune. Will take it very slow for sure.

10-31-2006, 10:52 AM	#8 (permalink)
Enthalpy EMS Harmonizer Join Date: Feb 2006 Location: Denver, CO Posts: 1,226 Thanks: 8 Thanked 55 Times in 43 Posts My Google Map iTrader Rating: (2/100% )	The Autronic has one of the absolute best interfaces for tuning that I have seen. It's not the simplest, but it is one of the best-organized. The Autronic is one of the few true speed-density EMSes around. Unfortunately, I have only tuned Subarus on them, so I don't have a base map for you. I can help you out with tuning, if you want.

10-31-2006, 11:12 AM	#9 (permalink)
Tylerfishsmith No Skills Join Date: Sep 2006 Location: Gulf Breeze, FL Posts: 51 Thanks: 0 Thanked 1 Time in 1 Post My Google Map iTrader Rating: (0/0% )	I really appreciate that. I will touch base with you later when I get SMC back and am ready to start car. I wish there was a way to interface the laptop output live online. Car could be tuned in cyberspace by someone like yourself who is experienced. That is walk me through it live. MMMM...need to think about this. A live public forum tuning a car. Having one of those Eureaka moments...I am sure it has already been done somewhere. Well, thanks again...will get back in touch later.

10-31-2006, 11:14 AM	#10 (permalink)
Tylerfishsmith No Skills Join Date: Sep 2006 Location: Gulf Breeze, FL Posts: 51 Thanks: 0 Thanked 1 Time in 1 Post My Google Map iTrader Rating: (0/0% )	Am going to wire in LC-1 instead of stock O2 this weekend. That way I can use the autotune feature. This is what really drew me to the SMC. Know anyone who has done this? Getting conflicting info from Innovate message board.

10-31-2006, 03:54 PM	#11 (permalink)
Enthalpy EMS Harmonizer Join Date: Feb 2006 Location: Denver, CO Posts: 1,226 Thanks: 8 Thanked 55 Times in 43 Posts My Google Map iTrader Rating: (2/100% )	I have tried the "remote tuning" thing. It doesn't work that well. A big part of the tuning is listening to the engine. The engine will tell you quite a bit of what you need to know, and if you aren't physically there, you don't get that quality of tuning. Autronic is one of many EMSes that does autotune. The Nemesis and AEM EMS does autotune as well. There's a trick with Autotune. Autronic tried to mandate you use their exhaust analyzer. People have gotten the LM-1 to work just fine with Autronic. You won't be able to use the Dyno Dynamics integration (which is software that communicates with the dyno to autotune). There was a website on the LM-1 and Autronic out there. I have always used the dyno wideband, so it's never come up with me. My email is damon.becker (at) comcast (dot) net. Drop me a line if you want help. For some reason, my email notification isn't working. I'll keep checking back on this thread, though.

11-15-2006, 03:05 PM	#12 (permalink)
Tylerfishsmith No Skills Join Date: Sep 2006 Location: Gulf Breeze, FL Posts: 51 Thanks: 0 Thanked 1 Time in 1 Post My Google Map iTrader Rating: (0/0% )	Now I am wrong on the pwr steering. Was looking at it again last night and noticed that the two wires from the steering ecu are out to engine ecu. Good thing I didn't pwr it up that way. I believe they are telling engine ecu when and how strong the steering pump is running so the load can be compensated for. The steering pump I believe to get it's signal via speed sensor in tranny. I am not going to pwr anything up and see how it works. Now I just need to pwr water injection pump and IC fan. Not sure where to pull pwr from. Thinking about the same leg as injectors and fuel pump. Think that will be OK. Have a 30amp inline fuse w/relay here. Thinking injection pump and spal fan should not overload. What do you think?

11-15-2006, 03:27 PM	#13 (permalink)
Enthalpy EMS Harmonizer Join Date: Feb 2006 Location: Denver, CO Posts: 1,226 Thanks: 8 Thanked 55 Times in 43 Posts My Google Map iTrader Rating: (2/100% )	You could test this easily enough. Fire up the key (engine off) and see if there's voltage between the probes and ground. If not, manually ground them. If the pump kicks on, then there's your answer. One is for idle control, and the other is for P/S activation. You would only be able to use one, unless you use the other for an idle-up valve activation, akin to the A/C idle-up function. As for pulling power, size the electrical loads you are imposing. The fan and pump might not be trivial. You might have to pull another source off that battery. The last thing you want to do is pop the fuel pump when you simultaneously start up 3 different motors (fuel pump, fan, W/I pump). When you start up a pump, it draws roughly 2X the power it does under steady-state. For my I/C, engine lid and W/I pump setup, I pulled a fused switched high (using my own relay) from the battery.