Anti-Lock Braking System (ALB)

The NSX ALB system, more commonly referred to as the ABS (Anti-lock Brake System). The system is made of a modulator, pump and an accumulator. This system was used in the 1990-1999 models, with the 1997-1999 modulator slightly different.
The system was completely changed in 2000-2005 to a more responsive, simpler integrated unit and renamed ABS.

Trouble Shooting

If the ALB pump times out at 120 seconds consistently it means that the system is not developing or sensing enough internal pressure. An unplugged or bad pressure sensor will also invoke the pump to time out after 120 seconds and throw the ABS light.
You may check the pressure sensor that is attached to the Accumulator (big metal ball). The round disc shaped sensor it attached with a banjo bolt. The sensor will read 0.0 ohms when system is fully pressurized. The sensor is infinite (open) in all other conditions.
If your ALB fuse is blown, check for rat bites on the lower pump motor wires. These motor wires seem to be a favorite of rodents to chew on, they are also very low on the vehicle with a nice platform for rats to stand on.
To bypass a non-functioning ABS system without throwing codes or warning lights is to simply short the pressure sensor connector (57390-SM4-003 001 SWITCH ASSY., PRESSURE) will cause the ABS system to show OK. The pressure sensor connector is the orange one underneath brake master cylinder, separate and use a jumper wire to short the connection that comes from the bulkhead. Pulling fuses, relays from the ABS will throw warning lights and also cause the TCS not to function.
The modulator can be rebuilt in the US for $795 by AutoECU //www.autoecu.com/ (information good as of 03/2006)

Parts Interchange

The 1997, 1998, 1999 ABS Modulators are slightly different to accommodate the larger spare tire. The modulator will swap with previous years 1991-1996, but you will have to re-bend the hard brake lines to the brake master cylinder.
The 2000+ ABS system is completely different under the hood.
The entire ABS system is made by Nissin Brake //www.nissinbrake.com/. Nissin parts are available through normal auto parts supply houses. Just because the dealer (Factory, HNA) only offers part assemblies does not mean small individual parts are not available through alternate means. Any good brake shop should be able to help you get exact OEM parts cheaper than the dealer.
The individual solinoids appear to be made by Sumitomo.
The pump assembly was used in the following cars:
Accord, Prelude 89-91
Legend, CRX 89-90

Part Numbers

The North America service procedure is that the modulator, pump and accumulator are to be replaced as whole assemblies. The replacement of these whole assembly are extremely expensive and, in most cases, unnecessary.
Outside of North America the servicing of the internals of the ABS system is recommended and parts are supplied.
B-24-10 ABS Modulator (LHD) (-’99) NSX
01 46175-671-651 5.0 SCREW, SOCKET
02 46472-568-000 1.0 PACKING, OIL BOLT
03 46669-692-003 1.0 SEAL, RESERVE TANK
04 57110-SL0-L01 1.0 MODULATOR ASSY.
05 57115-SL0-J02 1.0 BRACKET, MODULATOR
06 57116-SP0-305 2.0 HEAD SET A, MODULATOR
07 57118-SG0-801 4.0 O-RING, HEAD
08 57119-SL0-L00 1.0 GUARD, MODULATOR
09 57119-SL0-003 1.0 MARK, RESERVE TANK (ABS)
10 57120-SL0-013 2.0 PISTON COMP.
11 57121-SG0-801 2.0 SPRING, FR. MODULATOR
12 57141-SF1-801 2.0 SPRING, RR. MODULATOR
13 57174-SL0-A00 1.0 BRACKET, COUPLER
14 57181-SL0-951 1.0 HEAD COMP., SOLENOID (A)
15 57184-SL0-951 1.0 HEAD, SOLENOID (B)
16 57186-SL0-013 2.0 PLATE SET, SOLENOID
17 57188-SB0-801 1.0 JOINT, PUMP
18 57189-SL0-003 2.0 O-RING (P25.5)
19 57191-SL0-A01 1.0 TANK COMP., RESERVE
20 57193-SL0-003 1.0 FILTER, TANK
21 57196-SK7-003 1.0 CAP COMP., RESERVE TANK
22 57200-SL0-003 1.0 SOLENOID SET A, ABS
23 57204-SP0-003 4.0 O-RING C, SOLENOID
24 57250-SL0-003 1.0 SOLENOID SET B, ABS
25 57341-SL0-003 1.0 O-RING (P3)
26 57345-SL0-003 1.0 VALVE ASSY., RELIEF
27 90170-SL0-000 3.0 BOLT, FLANGE, 10X50
28 90673-SK7-A01 2.0 BAND, HARNESS
29 93403-0601605 1.0 BOLT-WASHER, 6X16
30 95701-0601605 4.0 BOLT, FLANGE, 6X16
31 95701-0601808 4.0 BOLT, FLANGE, 6X18
32 95701-0802005 3.0 BOLT, FLANGE, 8X20
33 95701-0803208 4.0 BOLT, FLANGE, 8X32
34 95701-1003208 2.0 BOLT, FLANGE, 10X32
35 57140-SL0-901 2.0 PISTON COMP., RR.
1 46462-SE0-000 003 BOLT, OIL
2 46472-568-000 007 PACKING, OIL BOLT
3 57070-SG0-801 001 ACCUMULATOR
4 57088-SL0-003 001 BRACKET, ACCUMULATOR
5 57090-SL0-J00 001 PIPE, ACCUMULATOR
6 57139-SB0-801 001 O-RING
7 57188-SB0-801 001 JOINT, PUMP
8 57199-SB0-801 002 CLAMP, HOSE, 14MM
9 57310-SL0-003 001 PUMP ASSY
10 57311-SG0-801 001 PUMP COMP
11 57318-SL0-000 001 COVER, ABS MOTOR
12 57348-SB0-801 001 BLEED, AIR
13 57349-SB0-801 001 CAP, AIR BLEED
14 57355-SL0-J00 001 BRACKET, PUMP
15 57358-SH9-800 003 MOUNT, PUMP
16 57360-SL0-003 001 MOTOR ASSY., ABS
17 57364-SB0-801 001 O-RING, MOTOR
18 57370-SL0-J01 001 HOSE COMP., PUMP
19 57374-SL0-J02 001 CLAMP, HOSE PUMP
21 57377-SL4-800 006 WASHER, ABS PUMP
22 57380-SL0-J02 001 HOSE, PRESSURE
23 57390-SM4-003 001 SWITCH ASSY., PRESSURE
24 90127-SB0-801 003 BOLT, SENSOR LOCK, 6X12
25 93401-0601205 002 BOLT-WASHER, 6X12
26 93403-0601608 001 BOLT-WASHER, 6X16
27 95700-0603208 001 BOLT, FLANGE, 6X32
28 95700-0606008 001 BOLT, FLANGE, 6X60
29 95701-0602205 003 BOLT, FLANGE, 6X22
30 95701-0602808 003 BOLT, FLANGE, 6X28
31 95701-0603205 003 BOLT, FLANGE, 6X32