Dreaded Yellow Lights....

[NSXGB]

Finally after over 6 years something seems to have gone wrong with my NSX...

Driving home last night 'sensibly' on the motorway, the ABS light came on, closely followed by the TCS light.
This morning armed with the jumper wire I extracted code 42 from the blinking ABS light. (TCS light continuously emits code 42 too).
So, I reset the ECU and take it for a spin. Nothing until I take a sharp left & TCS grumbles, followed by the TCS then ABS lights coming on again. However this time engine response is sluggish as if I'm in wrong gear. Driving normally after half a mile and engine back to normal....

Back home, jumper back in and I now get code 42 from the ABS & TCS lights on dash and code 36 from the ECL....

Looking here: http://www.nsxprime.com/wiki/Trouble_Codes
Code 36 = TCFC Signal & Code 42 = Rear HO2S Heater.


So TCFC Signal = Something to do with the Taction Control signal but not necessarily a broken ABS sensor?
Rear HO2S Heater = Rear O2 sensor...Seems strange to have two apparently unrelated problems all of a sudden?

My next step will be to inspect and clean all the ABS sensors as I've recently changed all the shocks and springs and may have dislodged something.

Hoping the O2 sensor code is just related to the way the TCS cut the engine power at the time, confusing the O2 sensor - is that possible? Car is decatted BTW.
Is there a rsistance check for the O2 sensor to verify it's health?

Any additional checks or advice welcomed.


I've searched the archives with no exact match for this problem....

[simonprelude]

I'd measure the resistance across the ABS sensors, you should be able to see straight away if one is dead with a multimeter.

[AR]

Isn't TFTC the temp sensor on the manifold? I could be mistaken.

Is the car running in limp mode?

Can you go into VTEC?

Cheers,

AR

[Kaz-kzukNA1]

Hi, NSXGB.

Code 42 from ABS and TCS is for the Front Left wheel speed sensor.

I think you referred to the wrong failure code chart and ended up with wrong result of O2 sensor related. You should use the one for ABS/TCS failure and not for the ECL/MIL one.

All of the four wheel speed sensors are connected to the ABS control unit and the signal is conditioned inside there and then passed onto TCS control unit.

ABS control unit will first test the wheel speed signal at the point of 15kph (just below 10mph) and then monitors continuously above this speed threshold for open circuit.
If it looses the signal for more than 0.5sec (depending on the speed), then the ABS warning light will be triggered.

TCS warning light will be triggered 3sec after loosing the wheel speed signal from ABS unit so this matches with your comment.

When you took the sharp left turn, TCS was activated for a short period before triggering the above failure but during the activation, it lost the wheel speed signal from ABS unit and this will trigger the TCFC failure (code 36 on ECL/MIL).
TCFC stands for the ‘Traction Control Fuel Cut’ signal so this is why you felt strange engine response.

So, first step is to check the Front Left wheel speed sensor. However, you seem to be able to drive the car even after exceeding the 15kph threshold for a while without triggering the ABS/TCS light so you’ll need to look further for intermittent short circuit somewhere on the wire or metal dust on the magnetic sensor head inside the front hub.


As you mentioned, you worked on the suspension area recently. Did you remove the 2 bolts holding the wheel speed wiring protector cover to the lower A-arm? If not, you may have streatched the wire especially when you are removing the original damper/spring from the chassis.

The orange 2 pin connector for Front Left wheel speed sensor is behind the octagonal shape fuse box under the bonnet. You may struggle to access it without removing some of the parts around there.
You should see about 750-1.2K ohm between the 2 pins.

I better stop here as I would like to watch the Singapore GP Q1.

Regards,
Kaz

[AR]

Kaz how mad is it that with the car stationary but with the Manifold temp Sensor disconnected ( I forgot to pulg it back up ) the car was giving me a TCFC sensor. All cleared up when the plug was reconnected and the ECU resetted.

[NSXGB]

Thanks for all your help.

Car seems to run fine, not in limp mode, vtec fine...


I think you referred to the wrong failure code chart and ended up with wrong result of O2 sensor related. You should use the one for ABS/TCS failure and not for the ECL/MIL one.


Thanks Kaz. I did not realise there were two fault code tables. :doh:


As you mentioned, you worked on the suspension area recently. Did you remove the 2 bolts holding the wheel speed wiring protector cover to the lower A-arm? If not, you may have streatched the wire especially when you are removing the original damper/spring from the chassis.


Yes, I removed the two bolts to free up the ABS cable. I was very wary of damaging the wire but maybe pinched it between the bottom of the shock and the A-arm at some point during the work?

It's taken 120 ish miles before failing which seems strange so I'm hoping it's just some dislodged dirt...


If I do need a new sensor, I see the options are HUK at £190+vat, order from the States or I see Midnight Blue in a previous post mentioned generic ones at a very reasonable price....anyone have any experience of these?

[britlude]

http://nsxcb.co.uk/testvb/showthread.php?t=4718

a straight forward job, just running the wires back to the connector is a bit fiddly! i got an oem sensor from the good 'ole U S of A, definately cheaper than HUK

[NSXGB]

http://nsxcb.co.uk/testvb/showthread.php?t=4718

a straight forward job, just running the wires back to the connector is a bit fiddly! i got an oem sensor from the good 'ole U S of A, definately cheaper than HUK


Thanks Jon.

[HONDANSXR]

hi my abs pump runs as soon as i set of (forwards) but not reversing out of driveway, it stays running until the lite comes on then stops , i have pulled the no.1-3 fuse and the pump stops , is this a front o/s abs sensor. also any ideas where to get front discs and pads (grooved ) from ...thanks in advance paul

[britlude]

hi my abs pump runs as soon as i set of (forwards) but not reversing out of driveway, it stays running until the lite comes on then stops , i have pulled the no.1-3 fuse and the pump stops , is this a front o/s abs sensor. also any ideas where to get front discs and pads (grooved ) from ...thanks in advance paul


that will be the abs solenoid system need a flush, or exercising.. find a dirty, dusty road, and slam the brakes on a few times, getting the abs so kick in.. exercising it, this may clear it, if not search 'abs flush' or solenoid exercising

[Midnight Blue]

If I do need a new sensor, I see the options are HUK at £190+vat, order from the States or I see Midnight Blue in a previous post mentioned generic ones at a very reasonable price....anyone have any experience of these?

Regrettably, the generic sensor I was talking about was the oxygen sensor and not an ABS wheel sensor.

Cheers,

Andy

[Midnight Blue]

that will be the abs solenoid system need a flush, or exercising.. find a dirty, dusty road, and slam the brakes on a few times, getting the abs so kick in.. exercising it, this may clear it, if not search 'abs flush' or solenoid exercising

If this doesn't work for you, and it may well be enough to clear the problem, don't despair and rush off to the main dealer prepared to hand over a bucket of cash.

Shortly after I got my car it did pretty much what yours is doing. I started doing the solenoid flush routine but the pump wasn't creating any system pressure. It turned out that the ABS pump was not pressurising the ABS system, because the valve in the pump was gummed open by old brake fluid. A quick tear down and clean fixed it.

The pump is limited to run for 2 mins. If at this point the system is not fully up to pressure, the pump will turn off and the dashboard warning light will illuminate.

Cheers,

Andy

[NSXGB]

Regrettably, the generic sensor I was talking about was the oxygen sensor and not an ABS wheel sensor.

Cheers,

Andy

Yes, thanks Andy. I looked up my error code on the wrong chart and diagnosed wrongly, I don't need an O2 sensor now.

[HONDANSXR]

thanks will try that

[Kaz-kzukNA1]

Kaz how mad is it that with the car stationary but with the Manifold temp Sensor disconnected ( I forgot to pulg it back up ) the car was giving me a TCFC sensor. All cleared up when the plug was reconnected and the ECU resetted.

Hi, Ary. Not sure which NSX you were referring to but I imagine it was on your 93 one.

Did you disconnect the TCS control unit to disable the Traction Control?
If so, you’ll get code 36 on ECL/MIL.

Also, if you forgot to connect the Intake Manifold Air Temp sensor, then you would get code 10 on ECL/MIL as well.

Regards,
Kaz

[AR]

Hi, Ary. Not sure which NSX you were referring to but I imagine it was on your 93 one.

Did you disconnect the TCS control unit to disable the Traction Control?
If so, you’ll get code 36 on ECL/MIL.

Also, if you forgot to connect the Intake Manifold Air Temp sensor, then you would get code 10 on ECL/MIL as well.

Regards,
Kaz

Kaz,

Spot on! I removed the whole TCS computer. All is well now, but it took some head scratching when it happened as it did not make sense. It must have stored the code. Thankfully it was OK after I reconnected the temp sensor.

Cheers,

Ary

[Chris B N]

Hi Hondansxr,
Bought grooved discs and Redstuff pads from
CRN
The Depot
Lincoln Street
Chesterfield
S40 2TW
tel 01246 559 933

They specialise in brake components and machine groove bought in blanks themselves.
I bought fronts and rears with Redstuff's for £249.99 inc VAT. I collected so price will be higher if posted from Chesterfield.
These and a fluid change worked wonders.

Chris B N

[NSXGB]

Got the ABS sensor wire from Andy at Vtec Direct. Thanks Andy.

All fitted and no more lights on the dash.

Was a bit of a PITA to fit as the alarm installer had run the alarm loom through the same area that the main wiring loom and the ABS wire connection is, making it very tight between the inner wing and the bulkhead. Fishing the plug through the inner wing past the main wiring loom and plugging it in was just about the hardest part of the job. I wish Honda had made the connector sit just a few inches further out along the inner wing to aid fitting....
The hub needed to be removed to gain access to the other side of the broken sensor to 'pursuede' it out of it's corroded hole. The new sensor would not go into the hole because of the corrosion, so quick clean up with some emery paper and the sensor slid home nicely.

Jobs a goodun'.