Isuzu N-Series. Manual - part 287

HSA (HILL START AID) 5A5-27

DTC 33 Control Unit Fault

Step

Action

Value

YES

NO

1

Disconnect the connector of the HSA control
unit, and then reconnect it. When the trouble
code “33” appears again, replace the HSA
control unit.

Is the repair completed?

—

Go to Step2

Go to Step1

2

After HSA repair, make sure no trouble is
found during self-diagnosis.

Is this step completed?

—

—

Go to Step2

5A5-28 HSA (HILL START AID)

DTC 36 Generator Terminal Output Does not Exist With the Clutch Engaged and Vehicle
Running

Step

Action

Value

YES

NO

1

Disconnect the HSA control unit connector “B-
285”, and start the engine. Is the voltage of
approx. 24V applied between the connector
terminal 10 “B-285” and the body ground?

Approx. 24V

Go to Step2

Go to Step3

2

Replace the HSA control unit.

Is the repair completed?

—

Go to Step4

Go to Step2

3

Repair the open circuit between the AC gen-
erator “L” terminal and 10 “B-285”.

Is the repair completed?

—

Go to Step4

Go to Step3

4

After HSA repair, make sure no trouble is
found during self-diagnosis.

Is this step completed?

—

—

Go to Step4

N5A3025E

HSA (HILL START AID) 5A5-29

DTC 86 Clutch Switch Does not Turn ON With Clutch Pedal Depressed

Step

Action

Value

YES

NO

1

Is the clutch pedal play normal?

—

Go to Step2

Go to Step3

2

Is there improper connection or damage in the
clutch fluid pressure switch connector?

—

Go to Step4

Go to Step5

3

Adjust the clutch play.

Is the repair completed?

—

Go to Step4

Go to Step3

4

Measure the resistance of the clutch fluid
pressure switch (at the switch side connector)
(with the connector disconnected). Is the mea-
surement completed?

5

Ω or more 

with clutch 

pedal 

released, less 

than 5

Ω with 

clutch pedal 

depressed

Go to Step6

Go to Step7

5

Repair the connector.

Is the repair completed?

—

Go to Step6

Go to Step5

6

Measure the battery voltage between the
clutch fluid pressure switch connector terminal
1 “B-102” and the body ground (with connec-
tor disconnected). Is the measurement com-
pleted?

20 V or more

Go to Step8

Go to Step9

7

Replace the clutch fluid pressure switch.

Is the repair completed?

—

Go to Step8

Go to Step7

8

Measure the resistance between the clutch
fluid pressure switch connector terminal 2 “B-
102” and the HSA control unit connector ter-
minal 6 “B-285” (with connector discon-
nected). Is the measurement completed?

Less than 5

Ω

Go to Step10

Go to Step11

9

Repair the open circuit between the fuse “F-
17” and 1 “B-102”.

Is the repair completed?

—

Go to Step10

Go to Step9

10

Connect all the connectors, turn the starter
switch to ON, engage the clutch then disen-
gage the clutch for 5 seconds or more, and
engage the clutch for 1 minute. Does the trou-
ble code “86” appear again?

—

Go to Step12

Go to Step13

11

Repair the wire between 2 “B-102” and 6 “B-
285”.

Is the repair completed?

—

Go to Step13

Go to Step11

12

Replace the HSA control unit.

Is the repair completed?

—

Go to Step13

Go to Step12

13

After HSA repair, make sure no trouble is
found during self-diagnosis.

Is this step completed?

—

—

Go to Step13

5A5-30 HSA (HILL START AID)

N5A3026E