EPS Error 22 - under inflation?

[unloaded]

For the past 12 months I've been driving my '96 Manual T-top without EPS.
While starting up one morning the EPS light stayed on and Power Steering was gone!
To be honest I've quite enjoyed the extra workout and as long as your on the move the car drives great without PS.

During my recent Honda major service I highlighted the problem and the service mechanics gave me a run down of the fix and the cause:
The tyres were incorrectly inflated with enough difference to cause the EPS to turn itself off.
Diags showed this as an error 22. Honda pumped my tyres to correct PSI and EPS functioned correctly.........

......for about 1 day!
So I am now back to EPS turned off. I've checked the tryre pressures expecting to find maybe one tyre to have a slow puncture - but all 4 tyres are 100% correct PSI.

It is true to say that the rear tyres are both now close to the legal limit........
but I'm really struggling to understand how minor tyre inflation differences or even tyre wear can throw the EPS into enough of an error to shutdown the EPS.
Has anyone else experienced EPS turning itself off?
Does the inflation/tyre wear argument make sense to anyone? Is the NSX brain really complex enough to measure wheel speeds to that degree of accuracy?

Any help/advice much appreciated!

[cas]

TCS will switch it self off if tyres are not right. Remove clock fuse to reset error codes does your EPS come on? Early cars had a problem with the eps control unit - if you moved the steering wheel while starting up it would switch off the eps. If it does come on retrieve the error code your self by shorting the connector - is it still 22? Good luck!

[unloaded]

Cas - Thanks for your repsonse!
No issues with the TCS.
EPS light is permanently on - confirming that Power Steering is permanently off.
Definitely not moving steering while turning on and the car isn't that early ('96), I'm sure its got something to do with these tyres and I guess since there have been no other replies it can't be a common problem. Will have to take expensive action and swap out the tyres!

[cas]

Hi,

Don,t replace your tyres unless they are worn becuause the error will still be there.

1. Reset diagnostic system by removing clock fuse.
2. Sit in car startand start the engine.
3. Take the handbrake off.
4. Is the power steering working when you try to turn the steering wheel?
5. NO. Big problem. Take to Handa and have a full inspection of eps.
6. Yes. Drive slowly down the road when does the EPS light come on?
7. Stop and get error code.
8. What is the error code? It could be a sensor is down possibly tyres but I have never come across that as a cause.

You said that you retrieved a code 22 that is the code that tells you the eps power unit has packed up. This is expensive. I know because when I bought mine the EPS did not work and the error code was 22. The Eps worked when I replaced the power unit. I would recomend that you take the car to a garage that understands NSX's. Hopwe this helps


Claudio

[unloaded]

Ok steps 1-6 I'm good with, but steps 7 and 8?

I got the error code from Honda, who said they just cleared it and ensured the tyres were all pumped to correct pressure.
From what you have said about EPS completely failing and bringing up same Error 22, I'm guessing that Error 22 covers a general EPS failure and there are probably a list of causes attributed to it - but since my tyres were at incorrect pressures Honda identified this as the fault.

So after another reset I now have EPS working again, I've given the car a varied test drive and restarted it several times to see if I can understand when it will fail again. So far no issues EPS light off!
I haven't had a chance to but I'm starting to be convinced that if I take it on a long straight road at speed the NSX measures of my wheel speeds will throw it into error again.

Thanks Claudio!! At least I now know how to reset the diags and be able to test whether it throws up a consistent failure.

[cas]

Hi

This is something that it is worth learning how to do. NSXprime has the user manual on line and a full decription of codes is in the manual. You don't need any special equipment only a paper clip and to locate the right connector - it is located in the passenger foot well behind the carpet. This site and NSXprime shows you how to do it and count the bulb flashes on the dasboard.

claudio

[Midnight Blue]

Hi,

Fault code 22 is BrianK's repair speciality. I believe it is the relays in the EPS power unit going weak. Details and prices on;

<nsxe-repair.com>

I spoke to Papalazarou a few weeks ago and he had his done in the UK at BBA-reman

Cheers,

Andy

[NSA]

I had the same problem and a new EPS unit solved it. I bought a repaired box from Papalazarou and had mine fixed. I can sell it to you for £260 including shipping, which is what it cost me.