Isuzu N-Series. Service manual — part 293

HSA (HILL START AID) 5A5-51

0.5BR

0.3W/B

PARKING

BRAKE

B-51

5

J-9

FRAME

12

0.3W/V

0.3W/V

3

4

10

0.3W/B

0.5W/B

0.5W/R

0.5B

0.5W/B

WITH
HBB

W/O
HBB

0.3W/R

8

H-5

H-5

RELAY ;
BUZZER

SHORT CONNECTOR

X-33

9

7

X-33

8

X-33

J-128

J-128

4

3

2

J-128

1

J-128

N-6

1

HBB
LEVEL
SWITCH

DIODE
BOX

PARKING BRAKE SWITCH

H-12

3

METER

N5A3035E

5A5-52 HSA (HILL START AID)

Symptom: Buzzer Beeps Continuously During Self-diagnosis (Trouble Code Output Im-
possible)

Step

Action

Value

YES

NO

1

Refer to “Symptom: HSA indicator lamp blinks
abnormally”.

Is this step completed?

—

—

Go to Step1

HSA (HILL START AID) 5A5-53

Symptom: HSA Warning Lamp Had Blinked or Buzzer Had Beeped In the Past (Currently
the System Is Normal)

Caution:

The trouble code 03 is displayed when diagnosing with
the fuse removed.
The warning lamp blinks when the HSA release adjust-
ment is set-up fully to the FAST side or SLOW side with
the HSA adjust switch depressed. With this condition,
the vehicle will move back when starting or brake drag-
ging. To prevent this, correctly adjust it.
Never operate the adjust switch while driving. Other-
wise, it will lower the driver performance.

Symptom

Possible cause

Action to be taken

HSA warning lamp had blinked in
the past.

The warning lamp blinked when the
back-up fuse “F-19” was discon-
nected.

The warning lamp blinked when the
adjusted value was extremely off
the point, or when the clutch play
adjustment was not completed.

This indicates no malfunction.

Properly adjust according to the
adjustment procedure.

The warning lamp blinked when the
HSA had been operated for 7 — 8
minutes.

Longtime alarm. This indicates no
malfunction.

The warning lamp blinked when the
vehicle had moved while the HSA
operating. (The warning lamp
blinked when the vehicle was
started with brake dragged, or when
the vehicle moved back because
the brake pedal was depressed
insufficiently.)

Vehicle motion alarm This indicates
no malfunction.

The warning lamp blinked when the
adjust switch “FAST” or “SLOW”
was depressed while the vehicle
running.

Fault in adjust switch (code 19) was
detected but not a malfunction.
(When turning the adjust switch to
OFF, the diagnosis stops and the
lamp goes off.)

HSA warning buzzer had beeped in
the past.

The warning buzzer beeped when
the HSA had been operated for 7 —
8 minutes.

Longtime alarm. This indicates no
malfunction.

The warning buzzer beeped when
the vehicle had moved while the
HSA operating. (The warning lamp
blinked when the vehicle was
started with brake dragged, or when
the vehicle moved back because
the brake pedal was depressed
insufficiently.)

Vehicle motion alarm. This indicates
no malfunction.

The warning buzzer beeped when
the starter switch was turned ON
with the back-up fuse “F-19” discon-
nected.

It was caused by the control unit
being reset, and not a malfunction.

5A5-54 HSA (HILL START AID)

HSA Control Unit

Removal

1. Remove the instrument panel ASM.

• Refer to the item regarding the instrument panel

in the chapter 2 body section.

2. Remove the ventilation duct.
3. Remove the HSA control unit.

• Remove the two installing bolts and nuts.

Disconnect the two connectors.

Installation

Install in the reverse order of removal.

N5A3037E