Originally Posted by
Kaz-kzukNA1;bt397
Hi, Keno.
What is the spec of your NSX?
For example, the year model?
Unlike the Classic ABS, the upgraded modulator is the same for both the RHD and LHD NSX.
Therefore, the pin out at the ABS modulator is the same for any NSX including the 02-R.
The different part no is for the software code difference.
02-R uses different ABS tuning setup.
All 8 brake pipes are different between RHD and LHD.
The two Orange connector inside the cabin that used to be connected to the original (Classic) ABS controller will have small difference on the pin out depending on the spec and year model of the NSX.
Because of this, you will need to either select the appropriate wiring connection or change the pin out depending on the spec of your ABS upgrade loom.
As far as I know, SoS loom may require swapping of the pin out at the [RELAY] connector for the ABS warning light circuit depending on the year model of your NSX.
Did you see anything in the installation manual from SoS regarding the possible requirement on the pin out modification at the RELAY connector?
You may want to take the photo of the RELAY connector from the direction looking INTO the WIRE side and NOT from the terminal side so that I can understand the pin out and wire colour used.
With the KSP loom, we need to arrange the wiring connection and relay in three different ways for the exact reason.
In Japan, these companies sold more than 600 ABS Upgrade loom.
I never heard any failure with the one from KSP and based on the feedback on the Japanese Forum, it is very unlikely to have failure on the loom from these suppliers and I think SoS is buying it from one of them.
Lots of people are misunderstanding the operation of the ABS.
ABS does NOT prevent the tyre from locking.
Instead, it controls the brake pressure to meet the targeted slip rate at each tyre.
The locking between the front (understeer) and rear (instability) tyre has different meaning so the tuning is different.
Therefore, quite often, the ABS may allow tiny amount of lock at a cetain tyre depending on how the tartgeted slip rate were mapped.
Under normal driving condition, most of the time, the max stopping power or stopping grip is generated when the tyre has just started to slip but the rate will be greatly affected by the load.
The brake test you carried out is not conclusive.
You don’t need your friend to monitor the tyre movement, you don’t need 30mph for the brake test and you don’t need to come to a complete stop.
While the tyre is still cold, just try the same test even at lower speed when/where it is safe to do so.
If your ABS is working, you will get noticeable kick back at the brake pedal before the car comes to a complete stop.
Reaction time and control of the upgraded ABS is so fast and delicate that you will notice significant difference in the kick back speed and the strength compared to the classic ABS.
The upgraded one feels like higher frequency (faster reaction time) but with milder kick back (faster reaction time with delicate control).
So, if you get the kick back at the brake pedal but your ABS warning light stayed ON, then your upgraded ABS is working perfectly fine and just the ABS warning light logic is reversed.
This should be easy to fix by modifying the pin out at the relay connector of your SoS loom.
If you didn’t get even a single kick back at the pedal, your ABS was indeed not working and the ABS warning light was true.
If that is the case, I’ll try the following first.
1. Read the ABS error code.
2. Follow the specific procedure to erase the error code on the upgraded ABS.
You can’t erase it by disconnecting the battery or pulling out the fuse.
You must follow the procedure described in the manual which will involve the brake pedal, IG switch, SCS, etc.
Once done, put ABS SCS terminal to how it was (i.e. disconnect it from GND level).
3. After erasing the error code, turn the IG sw ON but do not start the engine.
4. As soon as the IG sw is ON, the ABS warning light should come ON for about 2sec and then OFF.
5. Turn the IG sw further clockwise to start the engine.
6. As soon as you release the key to let it back to IG ON position, the ABS warning light will be ON for about 2sec and then OFF.
7. If the ABS warning light stayed ON even after 2sec at No.4 and/or No.6, the system failed during the initial diagnosis mode.
Read the error code and ignore the procedure #8 & 9 as you won't have ABS any way.
8. Drive as usual to cover most of the driving condition including some ABS exercise.
9. If you get the ABS warning light, read the error code again (if any).
I think this is enough for the time being.
Kaz
ABS Upgrade Support
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