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jjklongisland
01-16-2014, 09:48 PM
OK, so my car is in the shop getting my clutch put in and for the last two months my steering no longer tightens up when at speed. It is extremely annoying and I hate the way the car handles like this. I think I educated myself in that the way the system works is that at a certain speed a sensor actuates the EVO valve and it basically turns off the power steering stopping the fluid from assisting.

What is the trouble shooting procedure. What do I check first. The plug is plugged in by the steering pump. I believe there may be a module on the rear package tray for this feature. Somehow I believe there is also wiring that comes from the strut tower and is integrated with the ride control??? why i dont know. How can I check if the EVO valve is getting the signal? Any help would be greatly appreciative.

I have heard that sometimes you have to replace the steering rack because there is also a valve in there???? I am so lost and need some direction.

thanks

jjklongisland
01-17-2014, 09:43 AM
Still nothing.... I would love to have a conversation with someone who knows how the system works. If someone would PM me I will reply with my cell... thanks

Mike Puckett
01-17-2014, 11:54 AM
Check the plug at the EVO. On mine a few years ago I had that happen and found the insulation on the wires at the plug had pulled back exposing the copper wire and they were twisted shorting out. I redid the plug by coating the wires with RTV silicone to reinsulate them. No problem since.

KMT
01-17-2014, 12:34 PM
Seen this thread for tips on troubleshooting the EVO?
- http://www.sccoa.com/forums/showthread.php?t=116103&highlight=troubleshoot+evo

jjklongisland
01-17-2014, 03:11 PM
Seen this thread for tips on troubleshooting the EVO?
- http://www.sccoa.com/forums/showthread.php?t=116103&highlight=troubleshoot+evo

Thanks for the thread... I searched and searched and never came accross this thread. The attachments in this thread should definitely be put in a sticky in the faq section of ARC diagnostics!!!!

KMT
01-17-2014, 03:20 PM
ARC?

I thought we were debugging your steering :) I think you mean EVO...

The only time ARC and steering work together is when the steering wheel is turned at such a rapid rate as to signal for the auto ride system to tighten up the shocks. The wires on each shock are for the actuators, which are commanded by the ARC blackbox in the package tray. ARC on or off....shocks firm or soft, the steering system proper isn't affected.

jjklongisland
01-17-2014, 04:05 PM
ARC?

I thought we were debugging your steering :) I think you mean EVO...

The only time ARC and steering work together is when the steering wheel is turned at such a rapid rate as to signal for the auto ride system to tighten up the shocks. The wires on each shock are for the actuators, which are commanded by the ARC blackbox in the package tray. ARC on or off....shocks firm or soft, the steering system proper isn't affected.

As per your linked post
..I replaced the ARC module and...ahhhh...all is good! Steering's great again. Feels like my shocks may have been "stuck" in firm mode despite being in soft mode (even when the firm light was working) because, with the replacement module, the normal ride is much smoother. For a while, I'd thought it was odd that it was so difficult to feel the difference, compared to my last SC.
Thanks to all of you who put in your 2 cents. It was worth more than 2 cents to me."

I read through it too fast. I didnt realize his ride control wasnt working either. Mine lights up and still works. My only problem is the steering.

Shock Absorber Electronic Steering Sensor Input
An optical shock absorber electronic steering sensor (photo-cell) has the following characteristics:
It is mounted on the steering column tube.
It is used to establish the straight-ahead position of the steering wheel.
Once the shock absorber electronic steering sensor has determined this position, it can measure the steering wheel turning angles and then calculate the lateral acceleration that results.
If the calculated acceleration is greater than predetermined values, the shock damping is switched to the firm level of control. This input is not used until the vehicle speed is above 19 km / h (12 mph).
Once activated, the shocks will remain firm an additional seven seconds after the vehicle's speed and/or steering wheel position drops below the parameter levels.

So does anybody have an EVO for sale? Pardon my stupidy but is the EVO in the plug itself or the part between the pump and the plug???

SCDan35thANV
01-17-2014, 04:38 PM
been looking for an EVO myself and wasn't able to locate one new or used. If you find a line on something let me know. Thanks!

jjklongisland
01-17-2014, 04:40 PM
been looking for an EVO myself and wasn't able to locate one new or used. If you find a line on something let me know. Thanks!

Roger That! Please do the same for me... :D

S_Mazza
01-17-2014, 05:09 PM
I have had an intermittent EVO system failure, in which it quickly jumps to full assist and then back. Not much fun. :) The on-off nature of it leads me to believe that it's electrical in nature, but I have been too busy to track it down so far.

I do have a spare EVO valve, and I can say that it is quite simple in design. The high pressure feed comes in the end, is restricted by a pintle valve to the desired amount of pressure, and exits through a ring fitting on the side of the valve. The electrical component of the EVO itself is just one simple solenoid coil. The only ways it could go bad are a short from bad insulation (or gettin soaked somehow), or a broken wire inside (which seems unlikely). You can do a quick ohm check across the terminals of the coil. You can also open up the EVO valve from the backside and clean it out in case the pintle is stuck. I don't think there is an easy way to get at the innards of the coil, though. That would be a job for a rebuilder who has spares available.

With all that in mind, I think the two most likely culprits (by far) are the wiring to and from the system components, and aged components (electrolytic capacitors?) inside the ARC module itself.

Does anyone have pics of an open ARC module for reference? It's got a case much like an EEC case, but I haven't cracked one open yet.

S_Mazza
01-17-2014, 05:53 PM
P.S. - On the early model SCs, the EVO control is integrated with the ARC box. At some point, LX cars got EVO as well. I think it was 1993 or 1994. Those cars had a stand-alone EVO controller. I am not sure if the late model SCs had a separate EVO controller or if it was still integrated with the ARC for those two years.

SCDan35thANV
01-17-2014, 06:22 PM
I have an extra arc module I can test to see but the car has been down for a while due to the trans. I also believe I am getting an error code 17 on the arc system but it's been so long i could be wrong on the code. If it ends up being the ARC module i will tear the bad one apart and post pics might be a bit though.

Mike Puckett
01-17-2014, 06:36 PM
It's been my experience over the years that intermittent problems on machines that vibrate to any degree are caused by connectors, plugs, sockets, etc. As the cars age the metal pins corrode enough to cause a break and make connection. You could disconnect all of the plugs, spray them with contact or brake parts cleaner, and then reapply dielectric before reassembly. It might help some of these problems. A bad ground connection is something else to look at. It's amazing what a bad ground on a car can screw up. A lot of the relays have partially burnt points by now, too. At work we use a relay in the switching power supply of our older motor controllers and I'm constantly replacing them for customers. And don't forget my bare twisted wire scenario above.
I checked the EVTM book and there is indeed a direct connection between the two. The steering sensor feeds the ARC and the steering control is located in the ARC module. If anybody needs an ARC module, I have several. Send me the type code and I'll see if I've got one.

jjklongisland
04-02-2014, 07:58 PM
So I changed the EVO and still no bueno... I am going to change the ARC next... crossing my fingers... Hopefully thins weekend

bowez
04-03-2014, 06:49 AM
When I had issues with my steering it was a bad Capacitor on the ARC module. I'd suggest as opposed to just swapping parts open the module up and look at the board.

jjklongisland
04-03-2014, 07:33 AM
When I had issues with my steering it was a bad Capacitor on the ARC module. I'd suggest as opposed to just swapping parts open the module up and look at the board.

Good info... Hopefully thats what it is. I will see this weekend. thanks

sonrider657
04-03-2014, 12:41 PM
My ARC Module seems to be bad as well (similar power steering issues, shocks will not consistently go into Firm Mode, and I hear a clicking noise coming from the truck occasionally).

Stupid Question: How do I remove the shelf in the truck to access the ARC Module? Also, where can I get a new ARC Module?

KMT
04-03-2014, 12:55 PM
The rear package tray is pinned on one end and hinged on the other. Check the driver side for the twist-release pin.

Try the 'Want To Buy' forum to see if someone has one for sale.

sonrider657
04-03-2014, 01:49 PM
Thanks. Just pulled the ARC Module and broke it apart. Sure enough, it appears one, maybe two, capacitors are burned. Roadtrip to Radio Shack!

jjklongisland
04-03-2014, 02:04 PM
Wow, if I have time tonight I am going to do the same thing....

KMT
04-03-2014, 03:40 PM
Sure enough, it appears one, maybe two, capacitors are burned.

If you have time, can you update us about/if it cures both the steering issue(s) _and_ the clicking in the back, thanks.

sonrider657
04-03-2014, 03:54 PM
Will provide update. Here is a pic of the ARC Module opened up with a red circle around the two suspect capacitors and replacements from Radio Shack (the OEM Caps are rated at 105C whereas the Radio Shack caps are only 85C but given this modules rides in the trunk it shouldn't be an issue):

60205

jjklongisland
04-03-2014, 04:38 PM
Because I know nothing about capacitors and electronics... How do you know if a capacitor is bad?

KMT
04-03-2014, 04:52 PM
Typically, you can do a visual inspection to see if they have bulged/cracked and/or leaked.

You can also desolder and check them off the board (caution) to help troubleshoot issues with the overall circuit, ( http://www.electricaltechnology.org/2013/06/how-to-check-capacitor-with-digital.html ), but by the time you do that, you might as well just swap them out. It might be easier to swap in another module at that point, assuming you can get your hands on one.

bowez
04-03-2014, 05:54 PM
Those were the same caps that failed on my board. 100F 50V 105C for the larger one and 22F 25V 105C for the two smaller ones.

You MUST Reseal the leads on the capacitors or you still get faults, with high humidity. I used clear RTV.

The explanation I was giving was the Radioshack Caps are not as high tolerance as the OEM ones, DigiTech could be a source for higher quailty.


http://i984.photobucket.com/albums/ae327/bowez_2009/th_2013-01-03_14-56-08_667.jpg (http://s984.photobucket.com/user/bowez_2009/media/2013-01-03_14-56-08_667.jpg.html) http://i984.photobucket.com/albums/ae327/bowez_2009/th_2013-01-02_15-30-30_742.jpg (http://s984.photobucket.com/user/bowez_2009/media/2013-01-02_15-30-30_742.jpg.html)

sonrider657
04-04-2014, 01:42 PM
Update: Replaced capacitors and now everything works perfectly! :)

ARC properly engages "Firm Ride" under acceleration, braking, and cornering, as well as with the console switch. The power steering now has good boost at low speeds and properly reduces boost at faster speeds.

Total repair cost = $3.16 :D

KMT
04-04-2014, 01:44 PM
Thanks for the update - good job! No clicking?

sonrider657
04-04-2014, 01:53 PM
There is still a clicking when ARC engages and disengages. I think it's just a noisy solenoid.

jjklongisland
04-06-2014, 08:06 PM
So I opened my ARC module and everything thing ok I guess. No bulges or leaking. I then switched the arc module with one I got from another member of the forum and still no firm steering. So just to recap, replaced my EVO valve and also my ARC module and steering does not firm up when speed increases. I am no officially confused as to what the next step is. My firm handling seams to work its just my steering. I hate the way the darn thing drives without the firmness...

bowez
04-06-2014, 08:13 PM
Can you engage firm ride manually?

Sounds like time to Ohm the EVO and the harness.

jjklongisland
04-06-2014, 09:37 PM
Firm ride seams to work just fine. Engages in auto mode under hard acceleration, steering and braking and works fine when forced in FIRM. Its just for some reason the EVO orifice isnt controlling tighter steering. The manual refers to some Star??? tester. Dont know what that is? Would I need it to do the OHM tests

KMT
04-06-2014, 10:03 PM
The original STAR testers were just code readers AFAIK. You can buy a modern one for your car for less than $50 these days. Great tool for any SC owner and not that difficult to use.

Code: 52 O,R Power Steering Pressure Switch circuit open

See this page for a full list of codes and details on which are SC-specific [ http://www.njtacc.com/tech/eec_codes.html ]

jjklongisland
07-01-2014, 09:16 PM
Thread update... for anyone who cares I finally go the speed sensitive steering back working... It is so awesome to drive her now at highway speed... I am so happy. It turns out when I was changing my fan the other day and searching the fuse box for power my buddy pointed out a female plug unplugged. I thought that was odd and he searched around for a few minutes and found the male end jammed under the battery. Looks like my mechanic never plugged it back in many months ago when I did the timing cover gasket... It only cost me hours of trouble shooting, the cost of a replacement ride control module, replacement of EVO valve and lots of frustration... Wait until I give him an earful... :mad::mad::mad:

KMT
07-01-2014, 09:35 PM
At least that code 52 was reliable :)

jjklongisland
07-01-2014, 11:26 PM
At least that code 52 was reliable :)

Lesson learned... test the voltages first and make sure you have power to the components... :o:o:o

Ira R.
07-02-2014, 04:50 PM
Lesson learned... test the voltages first and make sure you have power to the components... :o:o:o

Importnant Lesson #1 learned as well...
Your mechanic, no matter how good, does not like working on these cars and probably does not know as much about them as he thinks either!! ;)

Ira

jjklongisland
07-02-2014, 09:08 PM
Importnant Lesson #1 learned as well...
Your mechanic, no matter how good, does not like working on these cars and probably does not know as much about them as he thinks either!! ;)

Ira

He openly admits he hates working on my car... lol... Unfortunately he is all I got. Its hard to find someone you can trust. Plus unless its a Chevy in his book its just another pile of crap...

aroot1
07-03-2014, 10:45 AM
He openly admits he hates working on my car... lol... Unfortunately he is all I got. Its hard to find someone you can trust. Plus unless its a Chevy in his book its just another pile of crap...

You need a new mechanic. The kind of quality of repair with leaving things unplugged and stuffed under the batt show chevy quality work. I say leave him to it, some people will just never learn. Find a Ford guy and you'll b happier

Adam