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If possible try and get the fault code, but to answer your question "if it's still ok to drive" then, from what I gathered YES. There is no "pressure" to speak of, as the EPS is an electric motor, not a hydraulic system. Kaz will point you in the right direction though, as I have not worked on many EPS systems yet.Quote:
Originally Posted by John C
Hi, John C.Quote:
Originally Posted by John C
EPS can fail in many ways.
On a certain case, it is fine to drive even with the EPS error because the controller is simply disabling the EPS but for other cases, you may cause extra damages inside the EPS rack if it is not addressed soon.
If it is error code #22 and if you didn’t have any other issues such as torque sensor failure or mechanical issues, then you may be able to fix the issue by replacing the power relays inside the EPS controller.
For this specific case, you are most likely to be fine driving with EPS error.
This is very likely to be the case if your EPS controller is #39980-SL0-023.
You can find the part no at the side of EPS controller case.
However, even if the error code was #22, you won’t be able to fix the issue by just replacing the power relays if you have mechanical failure.
Attachment 7772
This photo is from KSP Engineering in Japan and it shows one of the example of EPS failure with error code #22.
Even they replaced the EPS controller with known good one, the issue was still there and when they opened the EPS rack, it was full of rust.
The tierod/rack end dust boots were not installed properly and moisture got inside the steering rack causing lots of trouble. They managed to repair it but not something you want to do everyday.
If your torque sensor has failed, you will get additional error code and I’m afraid, at this stage, it is not possible to repair it. My friends are working on the replacement interface circuit at the moment.
So, first, please try to read the error code and ideally, check the part no on the side of the EPS controller case.
Kaz
Hi, My EPS has code #26, you can help me? What could be the problem?
I download the 1998 manual,
Code #26: "The Upper FET is stuck ON" see page 17-36....
but I don't have the page 17-36 :(
Hi, XaviCR.
EPS error code #26 was introduced only after Feb/97 models in Japan so presuming your NSX is UK spec, it would be the later models.
From these models, the rotation sensor was removed from the EPS rack and EPS controller hardware/software was also modified and thus, you should already have the latest spec power relays inside the controller.
Any other failure codes other than #26?
Did you experience any battery failure or jump started the NSX before getting the error code #26?
Did you fail to start the engine just before getting this EPS failure? Have you replaced your Main Relay already?
Can you remember the condition/situation when you triggered this EPS failure?
How is the condition of your battery terminals?
How old is your battery and do you use battery conditioner if you don’t drive your NSX regularly?
EPS error code #26 is only detected just after starting the engine until the EPS warning light distinguish itself so it's quite short period.
Once it is triggered, unless you reset the error code, EPS will be disabled.
If you checked all the connection to the EPS controller, EPS rack, battery terminals and battery itself, then please park the car with the steering straight and stop the engine.
Then, reset the EPS controller by removing the 7.5A clock fuse. Please note that this will also erase all of the engine ECU related study value.
Start the engine without touching the steering wheel. Please note that as you erased engine related study value, you may find your rpm going up and down for a while.
If you no longer get EPS failure, then stop the engine, re-start the engine and this time, turn the steering wheel left & right all the way.
This would be enough to start with as you have lots of things to check.
I have the manual even for this error code #26 but it’s all in Japanese with several diagrams…
Not easy to translate all of them and explain the procedure….
Kaz
My EPS stopped working today,warning light on continuously. Reading the error codes gives 34,36 and 38. The manual 19-46 gives34,38 as rear wheel pulsers which fits with my pre-existing ABS fault when pedal kicks back when coming to a halt and pump "chatters". Not sure what code 36 means,Any ideas would be welcome.
Hi, pralognan.
As for any technical questions, it will help if you can provide some basic info on your NSX.
Could you provide at least the Country spec, Year model, NA1/2, 5MT/6MT/4AT, any modifications, etc?
It will help if you can provide me with the first 7 digits (the characters shown as ' * ') of your VIN after the JHMNA*******.
Please do not post your full VIN on here for security reason.
Also, which error code (EPS, ABS, TCS, CEL, etc) did you read?
EPS does not utilise individual raw wheel speed signal for its control loop so I think you read something else.
Kaz
Dear Kaz,
UK spec,1991 model year,NA1,,4AT. JHMNA12600T0.No modifications except for Dali rice rocket aftermarket exhaust. I was reading EPS error code.
Thanks for super quick reply.
Hi, pralognan.
Thank you for the extra info.
Based on your VIN, I can confirm that it is indeed 91 model with 1st gen EPS system that has both the torque and rotational sensors on the EPS rack and the EPS controller is separated in 2 boxes as the Power and the Control units.
The reason I asked you about the error code was your reference to the workshop manual 19-46 in your post.
Section 19 is for the 'Brake (ABS)' and your very page is for the ABS warning light and not for the EPS one unless I’m missing something not in your above post.
Anything to do with the steering including the EPS is always in Section [Edit: 17] for NSX [Edit: English workshop manual].
Also, there is neither #36 nor #38 for EPS error code unless you magically managed to put the EPS controller into a different mode so another reason for requesting the clarification of which error code (warning light) you read.
By the way, as in my previous post above to another owner, did you jump start the car or had difficulty in starting the engine recently?
Could you kindly read all of the error codes including any other warning lights again?
Then, I recommend you to double check the battery connection for any loose connections especially at the GND terminal.
Once these are done, then as in my above post #25, please remove the 7.5A CLOCK fuse for more than 10sec to reset the error code on the EPS controller.
This will also reset the ECU but I’ll leave it for the moment.
Start the engine and if you don’t see the EPS warning light, carry out the test driving session until you trigger the EPS warning light.
Once you saw the warning light, please read the error code again.
Kaz
Dear Kaz,
Thank you for your reply. I thought sunday would be your day off! My copy of the manual deals with steering in section 17,and there I found code 34 for EPS control unit fault. The memory also showed faults 36 and 38. Not a magician,just retired Denso radiator man! Never jump start or difficulty starting.No other warning lights. All 3 codes,34,36,38 on the EPS red light.
This morning nice spring weather so investigation showed bad battery connection to GND. After battery removed and refitted(equivalent to clock fuse removal), no warning lights and test drive up a twisty mountain road all OK