Isuzu KB P190. Manual — part 1505

11B-66 ANTITHEFT SYSTEM

DTC 125 Output Alarm Horn Broken Wire

Step Action Value

(s)

Yes

No

1

Was the Antitheft System Check performed?

— Go

to

Step 2

Go to antitheft

System Check

2

Recheck the DTC.

1. Key position is “OFF”.

2. Install the Tech-2 on vehicle.

3. Key position is “ON”.

4. Check the DTC on the Tech-2.
Is DTC 125 stored?

—

Go to Step 3

Refer to

Diagnostic Aids

3

1. Check the alarm horn circuit for an open, short to

ground, or short to voltage.

Also, check the alarm horn connector for damage.

2. If a problem found, repair as necessary.
Was the problem found?

—

Verify repair

Go to Step 4

4

Check the alarm horn function.

1. Key position is “OFF”.

2. Connect a jumper wire between ACU terminal 5

and body ground.

3. Key position is “ON”.

4. Observe to operate sound with the alarm horn.
If the problem found about the alarm horn, replace as
necessary.

Was the problem found?

—

Verify repair

Go to Step 5

5

Replace the antitheft control unit (ACU).

IMPORTANT: The replacement ACU must be
programmed the security data by the Tech-2.

Was the action complete?

—

Verify repair

—