EPS Electronic Power Steering Please help.

Why does my Power steering work for a few mins after starting the car up then stops working? and throws the light on the dash.

Surely if there was a issue it would either work or not work?

It seems to have started since a clutch replacement, how could this be linked if at all? any earths or anything for the EPS around that area?

My mechanic actually said something like he didn't cause the issue, but it started happening after the clutch swap, this could have fallen inside the same time the coolant tank was upgraded.

Any suggestions, ideas would be greatly appreciated.

Thanks.

the EPS prob needs to be rebuilt there is a guy on prime that does this PM Vanhalla he is the master when it comes to this issue since he prob wrote the book on troubleshooting it

I'll be your huckleberry. Yeah, the book is about right. When mine started to fail it would go intermitently. One day was good. The next day it would die and that freakin' light would just glare at me. Sometimes I could reset it by pulling the clock fuse and putting it back in. I even sent the EPS control unit to BrianK to repair and that only lasted a week. When they start to go, well let's just say I know what's coming next.

You will need to pull the rack and send it to D1Guy here on Prime. He can fix it. Good luck.

Before dropping the RacK, I would have your Tech recheck all the connections associated with the Transmission removal, especially if you have any Ground or Battery cables that were disconnected.

Good Luck

Bram

Have you tried pulling your error codes & if so, what are they?

Please don't tell me it's as major as that.

It really did start as soon as a got the car back from a clutch swap. Was thinking it was something he missed like a earth as Bram mentioned.

It's too much of an coincidence.


I havn't no, i was wondering if i could pull codes for the EPS like the ecu. I have an OBD1, how do i pull the EPS codes? same method as the ECU codes?

when my eps light came on and steering failed, it turned out to be the ignition switch. cheap fix.

jaffaz32 said:

Please don't tell me it's as major as that.

It really did start as soon as a got the car back from a clutch swap. Was thinking it was something he missed like a earth as Bram mentioned.

It's too much of an coincidence.


I havn't no, i was wondering if i could pull codes for the EPS like the ecu. I have an OBD1, how do i pull the EPS codes? same method as the ECU codes?

Click to expand...

Yes I believe it's the same. Pull the code and that will give us something to go with.

dropping the rack suck major azz. I can drop the engine in an NSX faster than I could remove the rack LOL goodluck man
pull some codes report back

Sometimes an iffy battery can cause this to happen. It did on my car. Once replaced all ok. My battery seemed ok in all other respects....

Chris, I don't know why you never ask any Q's on the UK forum.. You know Kaz especially is extremely knowledgeable

jaffaz32 said:

Please don't tell me it's as major as that.

It really did start as soon as a got the car back from a clutch swap. Was thinking it was something he missed like a earth as Bram mentioned.

It's too much of an coincidence.


I havn't no, i was wondering if i could pull codes for the EPS like the ecu. I have an OBD1, how do i pull the EPS codes? same method as the ECU codes?

Click to expand...

Yes its the same procedure but you count the blinks on the EPS light instead of the CEL.

Just convert it to no power steering.

Ur arms will get larger.

BATMANs said:

Just convert it to no power steering.

Ur arms will get larger.

Click to expand...

^^^^^^Truth.

and u will experience proper steering input/road feedback that was part of the ORIGINAL design of the NSX. None of this afterthought through the years to get more people to buy NSXs.

A typical answer on UK forums is...

"it's modified, that's your problem." :tongue:

Kaz is very knowledgable and extremely helpful.


I will pull the codes at the weekend, was meant to this weekend but with the weather here i found my self helping with a fallen tree disaster.


I've recently joined the gym and the car with the eps light on is hard work haha.

I have a Braille Battery which can be a pain sometimes, i will try a spare. On that thought, isn't there a earth near that connects to the battery for the EPS? i wonder if my mechanic disconnected the battery.

is there a way to check the ignition switch?

Let's start first with a battery with a full charge. While changing that out there is a ground right behind the battery and the EPS torque sensor plugs into the main connectors right there too. Make sure the ground is tight (might be a good time to add a little Oxguard) and that the connector is tight. It should "snap" together. Then let's see if your power steering comes back. If not, check for error codes and we can go from there. If you are going to need to get it fixed, here is some light reading for you;
http://www.nsxprime.com/forum/showt...-Rack-Rebuild-Part-1-of-3?highlight=ep+repair
http://www.nsxprime.com/forum/showt...-Rack-Rebuild-Part-2-of-3?highlight=ep+repair
http://www.nsxprime.com/forum/showt...-Rack-Rebuild-Part-3-of-3?highlight=ep+repair

Hi, jaffaz32.

Before you touch the battery, please read the error code first.
You may loose one of the most important information in diagnosing the issue if you disconnect the battery or pull the fuse out before reading the code.


Then, please check the connection at the both battery posts especially the GND cable.
There is a GND wire from the EPS rack directly fixed to the battery GND cable terminal with a 10mm nut.
Poor battery connection or low battery voltage will trigger several warning lights such as EPS, ABS, etc.


Based on your other post regarding OBD1/OBD2 on this site, your NSX is likely to be UK spec 95 model.



If this is the case, you are very likely to have EPS controller ver. -023 (39980-SL0-023) and I’m afraid there is a known issue with this one and 100% guaranteed to trigger the EPS warning light sooner or later.
There are two power relays inside the controller and the relay capacity is not large enough under certain conditions that it will burn out the contacts resulting in EPS warning light.

Honda released TSB for Acura NSX with ver. -033 EPS controller for the similar reason and based on the information from other EPS owners, I know ver. -305 controller can also trigger the EPS light for the same reason.

For these controller versions, most of the time, the EPS error code will be #22 apart from the torque sensor failure at the EPS rack interface circuit.

There are other failure modes that will cause some of the FET to fail resulting in power assist in only one direction, etc.
For this specific failure mode, there will be no EPS warning light.


If your error code is #22, you will need to go through the procedure described in my blog at the NSXCB site.
http://www.nsxcb.co.uk/blog.php?1811&blogcategoryid=47




It will involve drilling extra holes on the board in order to install the high current capacity relays.










Some of the before/after photos...



All of the EPS controllers that I serviced with error code #22 showed burnt relay contacts resulting in poor relay operation.


If the EPS error code is related to the toque sensor or if you have rattle inside the rack, then I’m afraid you will need to service your EPS rack like others suggested.
It can be done in US or Japan.


So, first thing first, please read the error code and then check the status of your battery connection and the battery health.

Regards,
Kaz

Thanks Kaz, very informative as always.

I pulled the codes. 31 and 33.

I then checked the earths because it seemed odd to start after coming back from the garage, the earths were in a different location to where i had them. I cleaned them up and the bolt then installed all back together, reset the ecu and i appear to have power steering, wahoo.... so it's possible fixed. Time will tell. Thanks!!

There you go! Good job. Always pull the fault codes first so we know to start looking. Glad you got it going now report back around St. Patrick's day and let us know if it still works.

It's back....

I don't drive my car much, after pulling the codes and then resetting the ecu.

The EPS light popped back and i had no power steering again.

Resetting the ecu helped as it couldn't of been the earths i thought as it wouldn't of came back so soon.

Here is a video also...

Everyone loves a video.


Any ideas what codes 31 and 33 mean? or what i could at least try? Or is it even serious?

Thanks.

Code 31 is Power Supply and the likely targets are ECU and ignitor inputs.
Code 33 is your Speed Sensor Signal.

Code 33 might hold the answer as you stated this happened right after a clutch service. Double check your speed sensor to make sure it is connected tightly. If you have a buddy with an NSX, you might try swapping speed sensors just to see if this mimics the same problem on his/her car. You will find it on the upper back side of the transmission. It's a real pain to get to but at least you can see it from the top side. Speed sensors aren't that expensive but....

You could try moving the battery out of the way so that you could get to the wires and connector that powers your steering rack, just to see if they are loose. You could also troubleshoot with an ohm meter per the Service Manual starting on page 17-51. If all else fails, you can contact D1Guy and he might be able to steer (sorry, I just couldn't help myself) you in the right direction. Good luck.

Valhalla said:

Code 31 is Power Supply and the likely targets are ECU and ignitor inputs.
Code 33 is your Speed Sensor Signal.

Code 33 might hold the answer as you stated this happened right after a clutch service. Double check your speed sensor to make sure it is connected tightly. If you have a buddy with an NSX, you might try swapping speed sensors just to see if this mimics the same problem on his/her car. You will find it on the upper back side of the transmission. It's a real pain to get to but at least you can see it from the top side. Speed sensors aren't that expensive but....

You could try moving the battery out of the way so that you could get to the wires and connector that powers your steering rack, just to see if they are loose. You could also troubleshoot with an ohm meter per the Service Manual starting on page 17-51. If all else fails, you can contact D1Guy and he might be able to steer (sorry, I just couldn't help myself) you in the right direction. Good luck.

Click to expand...

That is helpful as it points me in the right direction. If the speed sensors are cheap enough i might just order a new one. Do you know the part number? my car is going on the ramps next month, i will see if i can swap this out at the same time.

I will also remove the batter and tray to have a proper look underneath. I have a couple of negative cables going to the battery, one is the power steering the other i'm not sure but would like to work out what it is.

Think i found them... http://www.rockauto.co.uk/catalog/x,carcode,1000887,parttype,10634 All around the same price, what is the better brand? mine is a 5 speed are they the same part as the 6 speed? just in case their site is wrong.

Thanks.

Hi, jaffaz32.

For EPS error code #33, if your NSX is 91 – 94 model and if your speedo needle is acting erratically such as jumping around, suddenly drops to 0, vibrating/oscillating rapidly, etc, then I would replace the VSS (VSS1 sensor).

However, if your speedo is fine, the issue started after having your CL service and if your NSX is 95+ model, then I strongly recommend you to check the VSS2 sensor sitting very close to the VSS1 one.
From 95+ NSX, the EPS software was modified and VSS2 sensor was added on the gbox.
It compares the trigger frequency against VSS1.

Changing the final ratio within the certain ratio window and if driven at high speed, it will trigger the EPS #33 on later spec EPS controller but not on the 95 controller so you can ignore this factor.

Several owners experienced EPS #33 error code due to VSS2 connector not fully locked or the VSS2 sensor head being scraped off due to aftermarket DF/final ratio modification, etc.

Did you make any modifications to your final ratio or DF at the time of CL service?


EPS #31 is very common if you had to jump start the car, low voltage at the time of cranking, poor battery terminal connection, etc.
You really need healthy battery with adequate capacity or use battery conditioner if you are not going to drive your NSX for a while.

Hope your issue is simple as loose connector, weak battery or poor battery connection.

Kaz

I had a different LSD and Final drive installed couple years ago.

It seemed to start happening straight away after my clutch swap. Mechanic brushed it off and didn't want to know.

My car is the one that's registered as a 1997 but is a 1995 model.

I do have to jump start my car, i really need to get a outside plug installed so i can get a battery tender. I tried one of those solar panels without much luck. Worth a try i thought.

So could well be either that sensor or the battery.

Thanks it's given me a good place to start.

Jaffraz32,
You can also and very easily trigger the EPS31 code if your main relay is starting to fail, and introduces intermittent, momentary 'cuts' in power.
Have you seen, say, the speedo and rev counter drop to zero and then resume their previous position.
Duncan