R32, R33, R34 GT-R – 300ZX Hicas Self Diagnostic Procedure

If you are having issues with your HICAS system, such as a trouble light in the dash, or heavy steering, here are the procedures for self diagnosis.  These are 25 to 30 year old computer systems, so they don't pick up every fault or issue with the system. However knowing the codes, if any will certainly aid in troubleshooting.  It is common to remove, lockout, or delete Super Hicas.  A bad alignment, the wrong steering wheel, the speedometer not working, and a low fluid level can all trigger Hicas lights. We also commonly see Hicas lights on cars that have a failing alternator. If you only see it under certain conditions, but then goes away. 

R32 GT-R Hicas Diagnostic

Self-diagnosis procedure

a) Input starting conditions for self diagnosis
1) Turn ignition switch "OFF"
2 M/T : Set shift lever to netural
   A/T : Set shift lever to "P" or "N"
3)Start engine
4)Turn steering wheel from left to right (at least 20 deg from the netural position) 5 times or more, then depress the foot brake pedal at least 5 times, all within 10 seconds after ignition switch has been turned "ON"



b)Input self-diagnosis item
1)Depress and release foot brake pedal
2)Turn steering wheel from left to right (at least 20 deg) from the neutral position.
3)M/T vehicles. Depress clutch and move shift lever to any gear other than neutral, and then return clutch and shift lever to original position
A/T vehicles. Disengage and engage parking brake lever. Move shift lever to any position other than netural or park, and return it to park
4) Move car at least 2-3 meters (7-10 feet) forward and proceed at an indicated speed of at least 1 mph in self diagnosis mode.

c)Self diagnosis codes - R32 GT-R
1) RH solenoid output
2) LH solenoid output
3)Fail-safe valve output
4)Power steering solenoid output
5) Vehicle speed signal
6) Steering angle sensor
7) Steering angle neutral signal
8) A/T parking brake signal, M/T clutch signal
9) A/T inhibitor signal, M/T neutral signal

Reading Hicas self diagnosis codes

d) Self diagnosis display pattern
1) When all systems are normal
     A) HICAS light flashes at 0.25 sec (4HZ) intervals
2) If fail-safe system was operated(fail safe valve is operating) when ignition switch was last turned OFF, fail safe items will be displayed in numerical order in modes indicated. After all items are displayed, display is repeated again.

e) Cancelling self-diagnosis
Three methods
1)Turn ignition switch off, or
2)Drive over 19 mph, or
3)After 5 minutes, the self diagnosis procedure will automatically cancel.

400R R33 GT-R. Only 40-44 cars made

R33 GT-R HICAS DIAGNOSTIC

Self Diagnostic Procedure 

1. Start the engine 

2. Within 10 seconds after turning the key to 'ON', start the engine, turn steering wheel from left to right 20 degrees from neutral 5 times or more times & pump the brakes 5 times. Then press the brake pedal again to enter the test mode.

Diagnostic Item Input 

1. Move the vehicle one or two meters at a very low speed

2. Turn the steering wheel more than 20 deg right to left once or more.

Diagnostic Item 

11 HICAS control unit

12 HICAS motor power supply not present

13 HICAS motor output not present

21 Vehicle speed sensor not present

22 Steering angle sensor not present

23 Steering angle sensor neutral or not present

24 Rear main sensor input not present

25 Rear sub sensor input not present

31 Parking brake sensor input not present

32 (Auto) Inhibitor switch input not present; (Manual) Neutral switch input not present

33 Engine speed signal not present

R34 GT-R Hicas Diagnostic

Self Diagnostic Procedure
1. Start the engine
2. Within 10 seconds after turning the key to 'ON', start the engine, turn steering wheel from left to right 20 degrees from neutral 5 times or more times & pump the brakes 5 times. Then press the brake pedal again to enter the test mode.
Diagnostic Item Input
1. Move the vehicle one or two meters at a very low speed
2. Turn the steering wheel more than 20 deg right to left once or more.
Diagnostic Item

11 Control unit

12 Motor power supply

13 Motor output

21 Vehicle sped signal

22 Steering angle signal

23 Steering angle netural signal

24 Rear steering angle main sensor signal

25 Rear steering angle sub-sensor signal

33 Engine speed signal

41 Yaw rate signal

300ZX Procedure

Turbos come standard with High Capacity Actively Controlled Suspension, a fancy way to say 4 wheel steering. There's a visual diagnostic mode to check for problems in the HICAS functions. The 90-93 TTs have hydraulic HICAS running off the power steering pump, where '94+ utilizes electric actuators to handle the rear steering chores. Their codes are a little different, but the procedure is the same. It might required a few tries to make it work. Be persistent!
Procedure:
1. Ignition switch 'off' manual tranny in neutral or A/T in 'P'
2. Start the engine
3. Within 10 seconds after turning the key to 'ON', start the engine, turn steering wheel from left to right 20 degrees from neutral 5 times or more times & pump the brakes 5 times. Then press the brake pedal again to enter the test mode.
4. Turning the steering wheel left or right past 20 degrees from neutral will cause the rear wheels to turn slightly (~1 degree) (1.).
5. Drive the car forward 15 feet under 9mph to enter the full diagnostic mode.
6. The HICAS dash light will flash a code indicating any problems. Long flash is first digit, short flash is 2nd digit.
7. Diagnostic mode is exited when: ignition is turned off, vehicle speed exceeds 9mph, or diagnostic has operated for 5 minutes.

HICAS light codes for '90-'93:
1. HICAS solenoid R.H.
2. HICAS solenoid L.H.
3. Cut-off valve
4. Power Steering solenoid
5. Vehicle Speed sensor
6. Steering angle sensor
7. Steering Neutral positon sensor
8. A/T: Parking Brake Sensor M/T: Clutch sensor
9. A/T: Inhibitor sensor M/T: Neutral sensor
HICAS light codes for '94-'99:
11. HICAS control unit
12. HICAS motor power supply not present
13. HICAS motor output not present
21. Vehicle speed signal not present
22. Steering angle sensor angle signal not present
23. Steering angle sensor neutral not present
24. Rear main sensor input not present
25. Rear sub sensor input not present
31. Parking brake sensor input not present
32. Inhibitor switch (A/T) or nuetral switch (M/T) input not present
33. Engine speed signal not present