Aaaarrrgghhh! Help required...

[flyingsniffer]

The tunnel crossing is booked, the hotel is booked, meet up with European colleagues and Dr.Mikey on the way down is arranged, track day insurance sorted, track day paid for (well, half a one anyway:)), car is cleaned and shiny. Made the fatal mistake of bringing it to work this morning 'just in case' and.....the red dash EPS light is on. It was all good on Sunday.

Checked fluid levels - OK (and no fluid on barn floor where it was parked). Main fuse - OK. No other symptoms, just steering is heavy. My car is an OBD2 and I have a basic fault code reader (Garmin mechanic) and it's not showing any fault codes on this unit.

Few questions:
- any simple/obvious fixes?
- if I can't fix it, is it advisable to take it on a road trip?

Bl**dy typical!

[Papalazarou]

Hopefully Kaz will come along and give you all the info you need. In the meantime, and sorry to deal in 'mights' it sounds like it could be the eps control box (situated under the carpet in the passenger footwell).
If it is, normally it only requires a little soldering to rectify the fault.
The same thing happened to me a the second day of ownership on my first NSX and I was left with three choices;
1. New control box from Honda £1300.00
2. Send to BBA reman (Kent) http://www.bba-reman.com/content.aspx?content=how_to_contact_bba_reman
3. Find a good tv repair shop that will attempt it.
I went with BBA reman in the end. But I had time. Not sure if you do. You can try the click fuse trick, but it's not a long term fix and may cause you other issues.

Good luck,

James.

[nobby]

hope you get a solution mate ... sorry to hear

worst case can he not disable it and drive the car non assisted?

[Papalazarou]

Just got a message from Hagasan. He can't post at the moment, but wanted to pass on that he has a spare control box, if necessary. Also, had you considered the fault might be as simple as a low battery charge?

Cheers,

James.

[flyingsniffer]

Just got a message from Hagasan. He can't post at the moment, but wanted to pass on that he has a spare control box, if necessary. Also, had you considered the fault might be as simple as a low battery charge?

Cheers,

James.

Thanks. A bit of a look up on Prime showed a few people having luck with the clock fuse reset and sometimes low battery voltage - even cleaning up the terminals. My battery is a Halfrauds special so a better unit might be in order just for safety's sake. It is a small battery for the application so I guess it needs to be in tip top condition.

I'll have a play about at lunchtime and see if any of that works. But Hagasan's offer of a unit is very welcome.

[Kaz-kzukNA1]

Hi, flyingsniffer.
Not sure when you are leaving for the trip so going to suggest the easy things first.

1. Please read the error code before doing anything.
You must use the blue 2pin SCS method at the passenger foot well for this as EPS is not on the OBD2 data stream on our NSX.
Probably you already knew the procedure but it may help other owners......

How to read the error code... SCS terminal (http://www.nsxcb.co.uk/showthread.php?9229-How-to-read-the-error-code...&p=85855#post85855)

2. As James suggested, please check the health of your battery as well as the connection at both battery posts.
If it is loose and already over tightened in the past, just roll thin food foil and wrap it around the posts so that you can fatten it before clamping the cable terminal.
Again, you must read the error code before doing this otherwise you are going to erase the code.

3. After you read the error code and if you didn’t have to disconnect the battery, then just pull the 7.5A CLOCK fuse inside the pentagonal fuse box under the bonnet or disconnect the battery if you want to replace it or clean it any way.
This will erase the EPS error code as well as any other codes on other controllers (except the ABS error code if you have the upgraded/latest single body ABS) so another reason why you must read the error code first using the blue 2pin SCS connector before removing the CLOCK fuse or disconnecting the battery.

Please note that this process (removing the fuse or disconnecting the battery) will not only erase the error code but also reset all of the study values (and the status flags on OBD2 model which is the case for your NSX) stored in the ECU so you need to re-learn these if you want to quickly sort them out.

It will eventually re-learn everything over many-many miles so not a big problem but if you want to sort them out before leaving for the long trip, then
just warm the engine up to the operational temperature and
switch off all the electronics devices such as A/C, headlights, etc before stopping the engine.
Pull the 7.5A CLOCK fuse to reset the ECU or use your OBD2 reader to reset the ECU.
Start the engine while it is still hot and do not touch the TH pedal or any electronics devices including the steering and
keep the engine running under no load condition for about 15min.
Stop the engine and just re-start immediately to confirm that the idle rpm settles at about 800rpm as soon as you start the engine.

You can stop the engine now or go out for driving.
Other OBD2 flags will require some time to be set but I'm quite sure you will go through these specific driving mode during your long trip.

4. Try to park the car with steering pointing straight so that there is no load input at all.
Start the engine without touching the steering wheel even while cranking and wait for a few seconds until the EPS warning light disappears before touching the steering wheel after the engine started.
This is because there is a very short check mode that happens immediately after starting the engine and finishes as soon as the EPS warning light disappears.
If no error detected during this short period, you won’t trigger this specific error mode until next time you stop and start the engine.
For other error codes, your EPS light may stay On until you switch off the engine depending on the failure mode.



As long as everything was fine until this morning,
you don’t have other mechanical/electrical failures and
your speedo doesn’t jump around,
then it is very likely to be electrical issue inside the EPS controller or EPS rack related so
you are very likely to be fine driving with EPS warning light on the dash but without any power assist.

Please check the local regulation as some countries may have certain restrictions on driving with specific warning lights.



As it is EPS, it’s electronics so no hydraulic involved and thus, no fluid leakage.


If it is caused by the EPS controller and if it is power circuit related, then you may be able to fix it by carrying out this.
http://www.nsxcb.co.uk/blog.php?1811&blogcategoryid=47


If it is EPS rack related, you may need to refurbish it.
I know there is someone doing the service in US but I have never seen the actual process and based on my experience, I can only recommend KSP Engineering in Japan for this service as they have the know-how and made the special jig for this.
Even the Honda garages in Japan are sending the EPS rack to them these days as the MOT in Japan is very strict that any play/rattle on the rack or of course the warning light will fail the MOT.



When doing any services on EPS, you must consider the entire system such as the EPS controller, EPS rack, warning light circuit, etc as a package.
Therefore, please be careful when considering the spare controller.
If you ignore the software changes and specific circuit board modifications, broadly speaking, there are 2 kinds of EPS rack and 3 types of EPS controllers.

If your NSX is 2001 model, then you are very likely to have EPS controller -053 version.


From the EPS rack point of view, the early models have both the rotational and the torque sensors.
On the later model ones, there is no rotational sensor and just the torque sensor.

From the EPS controller point of view, the original design was two body style (power box + control unit).
Then, from 95 models, it was combined into one box solution.
From 97 onwards, there is no more rotational sensor input at the controller.


So, depending on the combination, you can’t physically connect the controller and the rack without the usage of an adaptor loom.

Or, even you managed to connect it, the system will trigger the EPS warning light and you will end up with no power assist if the controller doesn’t see the required sensor signal from the rack.

For example, you can’t connect the EPS controller from 91 – 96 models that requires the rotational sensor signal to the EPS rack from 97 model onwards because of the lack of rotational sensor on it.

Hope you can read the error code, enjoy the trip and after you returned, if it is power circuit related, I may be able to help you.


Kaz

[flyingsniffer]

Wow, thanks Kaz, your advice is as always invaluable.

I have sent you an email to avoid clogging up the forum. Safe to say the problem is not going away simply :(.
Regards

Rob

[Hagasan]

Hi Rob, I asked James to post on my behalf as I couldn't post from work but could view the forum. I had EPS issues a few years ago and mine was simply a below par condition battery. It was only a suggestion that I asked James to mention as sometimes the easiest things can be over complicated. It seems for you maybe you are not so lucky...Also, you should be fine driving the car without the power steering annoying and heavy as it will be. I have two controllers, one an -053 from 2000 and the other an -073 from 2004. You are welcome to try them if you can drive down to me. They will both fit your car. Nearest point of reference is M25 Jct 18. I don't have the time with my shifts to run around at the moment. I'll PM you my number...Cheers, Gary PS. Does anybody know why the carriage return button will not work for me on this forum? It's only on here!! Hence why my post is a long one liner....

[flyingsniffer]

Update for all...I think it's fixed (phew!).

As Hag and Kaz both identified, the easiest/obvious thing is the best place to start. A few error codes on the SCS method (I think 33 on the EPS light, 61 and 64 on the ABS light). However, my negative terminal on the battery looked fine but giving it a tug, it was obviously a bit loose. So took it off, cleaned it up and put it back on tight. Following Kaz's re-initiation process above, the EPS light is now out and after a 10 mile run, no re-occurence :).

Thanks for all input and offers of help (what did we do before the internet and forums?!). I hope this is thread closed.....

So roll on Friday! Le Mans, here we come!

[drmikey]

Update for all...I think it's fixed (phew!).

As Hag and Kaz both identified, the easiest/obvious thing is the best place to start. A few error codes on the SCS method (I think 33 on the EPS light, 61 and 64 on the ABS light). However, my negative terminal on the battery looked fine but giving it a tug, it was obviously a bit loose. So took it off, cleaned it up and put it back on tight. Following Kaz's re-initiation process above, the EPS light is now out and after a 10 mile run, no re-occurence :).

Thanks for all input and offers of help (what did we do before the internet and forums?!). I hope this is thread closed.....

So roll on Friday! Le Mans, here we come!

Phew glad its sorted - looking forward to our rag down the A26!

Fortunately my EPS problem was solved today with the arrival of a new EPS computer from the states (just in time)

Although TBH, you get used to driving without EPS - I quite like it at speed!

[Kaz-kzukNA1]

Update for all...I think it's fixed (phew!).

........... A few error codes on the SCS method (I think 33 on the EPS light, 61 and 64 on the ABS light). ....................
Hi, flyingsniffer.
Seems like the issue is solved for now and I’m glad that it wasn’t EPS controller related.

For your reference, EPS code #33 will be triggered if there is discrepancy between the VSS1 and VSS2 signal (Vehicle Speed Sensor and DF ring gear pulse counter).

It is quite popular for VSS1 sensor to fail so next time when you see the EPS warning light, please take a quick glance at your speedo to see whether the needle jumps erratically or not.

I have also seen VSS1 signal failure caused by an aftermarket parts installed and breaking into the VSS1 signal line.

From time to time, I saw the drive gear/ring on the DF case that drives the VSS1 sensor getting loose and shifted although it was not enough to cause VSS1 failure.

VSS2 sensor could physically get damaged if the EPS was installed after the car has left the factory but this is not the case on your NSX.
Similar thing can happen if you installed aftermarket DF or increased the final ratio but not the case for your NSX.
Weak power supply voltage could cause VSS1 and VSS2 signal issue and noise.


As you experienced, under EPS code #33, you won’t loose power assist until you turn the IG off.
EPS controller will simply stop the car speed related algorithm and goes into full assist mode so your EPS is still active in someway.


The typical cause of ABS code #54 (Fail Safe Relay, FSR) and #61 (FSR +B) is the weak battery.
If you had to jump start the car in the past, it could trigger these error codes.

For the latest ABS, you can only erase the error code by following the specific procedure involving the SCS terminal, brake pedal and the ABS light.
In order to prevent future confusion, it is best to erase the ABS error code in the near future.

So, it looks like your EPS warning light was triggered by the failure/noise at VSS1 or VSS2 sensors or simply the weak battery or poor battery connection.


Kaz