Isuzu N-Series. Manual - part 243

ANTI-LOCK BRAKE SYSTEM (ABS) 5A4-37

Chart A-4, TA-4 Braking Sound (from Hydraulic Unit) Is Heard While Not Braking

Step

Action

Value(s)

YES

NO

1

Is this the first time the vehicle is being driven
after starting the engine?

—

It is self checking 

sound.

Normal.

Go to Step 2

2

Is vehicle speed under 10 km/h (6 mph)?

—

It is self checking 

sound.

Normal.

Go to Step 3

3

Check for the following condition:

• At the time of shift down or clutch op-

eration.

• At the time of low 

µ drive (ice or snow

road) or rough road drive.

• At the time of high-speed turn.
• At the time of passing curb.
• At the time of operating electrical

equipment switches.

• At the time of racing the engine.

Did it occur under any one condition above?

—

ABS may some-

time be actuated 

even when brake 

pedal is not 

applied.

Go to Step 4

4

Is there play in each sensor/wheel speed sen-
sor rotor?

—

Go to Step 5

Repair.

Go to Step 7

5

Damage or powdered iron sticking to each
sensor/wheel speed sensor rotor?

—

Repair.

Go to Step 7

Go to Step 6

6

Is each sensor output normal? (Refer to chart
C-1-1 to C-1-4 or TC-1).

—

Check harness/

connector for sus-

pected disconnec-

tion.

If no disconnection 

is found, replace 

EHCU.

Go to Step 7

Repair.

Go to Step 7

7

Reconnect all components, ensure all compo-
nents are properly mounted.

Was this step finished?

—

Repeat the “Basic 

diagnostic flow 

chart”.

—

5A4-38 ANTI-LOCK BRAKE SYSTEM (ABS)

DIAGNOSTIC TROUBLE CODES

Diagnostic Trouble Codes

Choose and trace an appropriate flowchart by the numbers listed below to find fault and repair.

* Important: DTC 20 (Reference Voltage High) cannot be indicated by Tech 2. DTC 20 can be indicated and confirmed
by flashing using Diagnosis Switch.

Code

Diagnosis

Item (except Wiring)

Chart No.

Flash 

out

Serial 

Communications

12

—

Normal

—

—

13

C0213

Vehicle Type Error

EHCU

1

14

C0214

EHCU Abnormality

EHCU

2

15

C0215

Low Power Voltage

EHCU

3

25

C0225

Exhaust Brake Cut Circuit Abnormality

Relay or EHCU

4

33

C0233

Motor Drive Circuit Abnormality

EHCU

5

34

C0234

Abnormal Motor Rotation

EHCU

6

41

C0241

Solenoid Valve Power Supply Abnormality

EHCU

7

43

C0243

Solenoid Valve Circuit Abnormality

EHCU

8

45

C0245

Solenoid Valve Circuit Abnormality

51

C0251

FL Speed Sensor Circuit Abnormality

Sensor, EHCU

9

52

C0252

FR Speed Sensor Circuit Abnormality

10

53

C0253

RL Speed Sensor Circuit Abnormality

11

54

C0254

RR Speed Sensor Circuit Abnormality

12

61

C0261

Abnormal FL Speed Sensor Signal

13

62

C0262

Abnormal FR Speed Sensor Signal

14

63

C0263

Abnormal RL Speed Sensor Signal

15

64

C0264

Abnormal RR Speed Sensor Signal

16

ANTI-LOCK BRAKE SYSTEM (ABS) 5A4-39

DIAGNOSIS BY “ABS” WARNING LIGHT ILLUMINATION PATTERN

Diagnosis by “ABS” Warning Light Illumination Pattern

In the event that there is abnormality in the “ABS” warning light illumination pattern while the key is in the ON position
or if the warning light is actuated during driving, trouble should be diagnosed on a illumination pattern basis as follows:

No.

Condition

“ABS” Warning Light Illumination Pattern

Diagnostic

1

Warning light is actu-
ated normally

Normal

2

Warning light is not lit

Warning light lighting cir-
cuit trouble 

→ Go to Chart

B-1

N5A1061E

N5A1062E

5A4-40 ANTI-LOCK BRAKE SYSTEM (ABS)

Diagnostic Trouble Codes (DTCs)

When the warning light in the meter remains ON, the EHCU stores the fault identification and disables the ABS.

1. How to start DTC display:

• Confirm that the vehicle has come to a complete stop (with the wheels standing still) and that the brake pedal

is not depressed.
(Unless these two conditions are satisfied, DTC display cannot be started.)

• With the key switch OFF and short B-79 diagnosis connector terminal 12 to ground.

Then turn the key switch ON.

• DTCs can be displayed also by Tech 2.

The DLC (for Tech 2) Is Located Behind The Driver Side Lower Cluster Panel

2. DTC display:

• DTC is displayed by blinking warning light.
• Double-digit display.
• First, normal DTC 12 is displayed three times and then any other DTCs are displayed three times. (If no other

DTCs have been stored, the display of DTC 12 will be repeated.)

3

Warning light is actu-
ated while driving

Diagnostic trouble codes
are stored.
Display diagnostic trouble
codes and diagnose on a
code basis according to
the flow charts.

No.

Condition

“ABS” Warning Light Illumination Pattern

Diagnostic

N5A1063E

N5A1034E