View RSS Feed

Today at Atelier Kaz - Private NSX Enthusiast, ex-Honda R&D engineer with F1, Indy/CART background

ABS Upgrade (non-NSX), Health Check 03

Rate this Entry

Wanted to finish the modification of the ABS Upgrade loom to suit the non-NSX modulator before taking short break for the Christmas.

For those thinking of using the non-NSX modulator, please note that for the case of AP1 S2000 one, you will lose the TCS functionality.
Thank you to Jonathan (britlude) for his detailed testing including the pinout diagram, internal circuit board connection, etc;

This will trigger the TCS warning light as the required level converted w/speed signal no longer exists from the AP1 modulator (NSX ABS modulator has this feature).
For non-DBW model, you can simply disable the TCS by disconnecting all of the connectors from the TCS controller.
Never tried it on the DBW model but I think someone on here or Prime mentioned that it was the same as the non-DBW one???

There will be no more TCS light including the bulb check mode.

Because you will lose the communication link between the ECU and the TCS, it will always store CEL code #36 on the ECU but without triggering the actual CEL.
This is because CEL #36 is categorised as one of the failure mode that requires two consecutive error status within the same drive cycle and that's impossible when the TCS controller is not powered up.
That condition can only happen once per power cycle.

Strictly speaking, disconnecting the TCS controller could be against the local regulation but talking to the Honda dealer mechanics, some specific models didn't come with the TCS from the factory (like NSX-R, Type-S).
If you want to be thorough, you can remove the TC controller, disconnect the TCS stepping motor connector and replace the TCS enable/disable switch under the gauge assy with the blank one that is used on the Type-R/NSX-R/Type-S models.

The modulator doesn't have to be AP1 S2000.
Even before it was introduced on NSX Prime, several owners in Japan upgraded their classic ABS to the latest one body Bosch style modulator long time ago using the ones from other Honda models only available for Japan market.

When selecting the non-NSX modulator, there are several factors to be considered but if you select the right one, you can either swap it with the NSX one later without changing the bracket/pipes/etc or if your chassis setup is completely different from the OEM, you can just stay with the non-NSX option.

So, on this occasion, we are using AP1 S2000 modulator.

Depending on the ABS light circuit on the non-NSX model, the design of the ABS upgrade loom and the I/F circuit on your NSX (Honda did change the ABS light logic over the years), you need to review your ABS light driver circuit.

Also, based on the actual test carried out by the car manufactures and the official bodies, the cabin air temperature can reach around 60degC when parked under the direct sunlight in hot summer and the dashboard can reach 80degC even inside the cabin.

You can easily imagine what will happen if you park the car outside in the freezing cold winter.

Based on these, you must select the appropriate parts for the ABS upgrade loom.

If using SSR (Solid State Relay), please review the output target and apply protection circuit if driving any inductive load.
If using high sensitivity mechanical power relay, please review the current and temperature rate considering the potential extreme temperature environment inside the cabin.

For this owner, based on the year model and the load target, the appropriate parts were selected and the modification on the ABS upgrade loom was completed and ready to be installed.

If using different modulator or transferring the system to another car in the future, please remember to check the pinout and the I/F circuit.

Now time to take short break.



  1. britlude's Avatar
    Enjoy your break Kaz ��
    Updated 27-12-2018 at 03:47 PM by britlude