Page 128 of 4264
9A1-58 RESTRAINT CONTROL SYSTEM
Step Action Yes No
5 Measure resistance on SRS control unit harness connector from
terminal “41” to terminal “40” (ground).
Does 5-8840-0285-0 display “OL” (infinite)? Go to Step 6
Replace SRS
harness.
Go to Step 9
6 Measure resistance on SRS control unit harness connector from
terminal “42” to terminal “35” (ignition).
Does 5-8840-0285-0 display “OL” (infinite)? Go to Step 7
Replace SRS
harness or repair
chassis harness.
Go to Step 9
7 Measure resistance on SRS control unit harness connector from
terminal “41” to terminal “35” (ignition).
Does 5-8840-0285-0 display “OL” (infinite)? Go to Chart A
Replace SRS
harness or repair
chassis harness.
Go to Step 9
8
1. Ignition switch “OFF.”
2. Disconnect SRS driver / passenger load tool 5-8840-2421-0
from pretensioner assembly harness connector.
3. Connect SRS driver / passenger load tool 5-8840-2421-0 and
appropriate adapter to driver pretensioner assembly harness
connector.
4. Reconnect pretensioner harness connector as the base of the
driver seat.
5. Ignition switch “ON.”
Is DTC B0066 current? Go to Step 9
Ignition switch
“OFF.”
Replace driver
pretensioner
assembly.
Go to Step 9
9
1. Reconnect all components ensure all component are properly
mounted.
2. Clear diagnostic trouble codes.
Was this step finished? Go to the “SRS
Diagnostic System
Check” Go to Step 9
Page 340 of 4264
5A-24 BRAKE CONTROL SYSTEM
Getting Started
Before operating the Isuzu PCMCIA card with the
Tech 2, the following steps must be performed:
1. The Isuzu System PCMCIA card inserts into the
Tech 2.
2. Connect the SAE 16/19 adapter to the DLC cable.
3. Connect the DLC cable to the Tech 2.
4. Mark sure the vehicle ignition is off.
5. Connect the Tech 2 SAE 16/19 adapter to the
vehicle DLC.
060R300015
6. The vehicle ignition turns on.
7. Power up the Tech 2.
8. Verify the Tech 2 power up display.
060RW0009
Operating Procedure
The power up screen is displayed when you power
up the tester with the Isuzu systems PCMCIA card.
Follow the operating procedure below.
060R100102
Page 342 of 4264
5A-26 BRAKE CONTROL SYSTEM
DATA LIST (Tech 2)
The data displayed by DATA LIST are as follows:
Strings Units Description 2WD 4WD
Front Left Wheel Speed km/h (MPH)
Front Right Wheel Speed km/h (MPH)
Rear Left Wheel Speed km/h (MPH)
Rear Right Wheel Speed km/h (MPH) Start the vehicle and make sure of linear
change in each wheel speed
Brake Switch Open/Closed Brake switch is “closed” when brake pedal is
stepped on.
ABS Warning Lamp On/Off To be “Off” usually
EBD Warning Lamp On/Off To be “Off” usually
ABS Stop State On/Off To be “Off” usually
ABS Relay Active/Inactive To be “Active” usually
Return Pump Active/Inactive To be “Inactive” usually
DTC Status No DTC To be “No DTC” usually
4 Wheel Drive Status Yes/No To be “Yes” usually
-
FL Dump Valve Commanded
(Front Left) Active/Inactive
FL Isolation Valve Commanded
(Front Left) Active/Inactive
FR Dump Valve Commanded
(Front Right) Active/Inactive
FR Isolation Valve Commanded
(Front Right) Active/Inactive
Rear Dump Valve Commanded Active/Inactive
Rear Isolation Valve Commanded Active/Inactive
FL Dump Valve Feedback
(Front Left) Active/Inactive
FL Isolation Valve Feedback
(Front Left) Active/Inactive
FR Dump Valve Feedback
(Front Right) Active/Inactive
FR Isolation Valve Feedback
(Front Right) Active/Inactive
Rear Dump Valve Feedback Active/Inactive
Rear Isolation Valve Feedback Active/InactiveEach valve is “Active” when each valve is
opereted.
G-Sensor Output V 2.0~3.0V when vehicle speed is 0 km/h (flat
place) -
Battery Voltage V The voltage value currently supplied to EHCU
Diagnostics Connector Open/Closed Diagnostics connector is “Open” when
diagnostics connector is connected.
Page 348 of 4264
5A-32 BRAKE CONTROL SYSTEM
Diagnosis By “ABS” Warning Lamp
Illumination Pattern
In the event that there is abnormality in the “ABS”
warning Lamp illumination pattern while the key is in the
ON position or if the warning Lamp is actuated during
driving, trouble should be diagnosed on a illumination
pattern basis as follows:
No. Condition “ABS” Warning Lamp Illumination Pattern Diagnostic
1 Warning Lamp is
actuated normally
Normal
2 Warning Lamp is not
lit
Warning Lamp lighting circuit
trouble. Go to No ABS
Warning Lamp.
3 Warning Lamp
remains ON
Diagnostic trouble codes are
stored.
Display diagnostic trouble
codes and diagnose on a
code basis according to
the flow charts.
4 Warning Lamp is
actuated while driving
Diagnostic trouble codes are
stored.
Display diagnostic trouble
codes and diagnose on a
code basis according to
the flow charts.
Diagnostic Trouble Codes (DTCs)
When the warning lamp in the meter remains ON, the
EHCU stores the fault identification and disables the
ABS.
Page 349 of 4264
BRAKE CONTROL SYSTEM 5A-33
How to display and erase DTCs:
Note:
DTCs can be displayed also by TECH 2 use
“Diagnostic Trouble Codes“ mode.
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 condition are satisfied, DTC
display cannot be started.)
With IGN OFF, connect #12 terminal with #4
terminal or # 5 terminal (GND) . Then turn IGN
ON.
The DLC is located behind the driver side kick panel
This illustration is based on RHD model
350L300005
Keep #12 terminal connected with #4 terminal
or # 5 terminal (GND) during DTC display. (If
#12 terminal is separated from #4 terminal or #
5 terminal (GND) during display, display will
stop.)
2. DTC display:
DTC is displayed by blinking warning lamp.
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. How to erase code:
Conduct brake switch ON/OFF operation 6 or
more times within 3 seconds of self-diagnosis
startup.
The code cannot be erased if more than 3
seconds have passed since self-diagnosis
startup, or if self-diagnosis has started with
brake switched on (brake pedaled).
B05RW0005
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5A-34 BRAKE CONTROL SYSTEM
4. Notes
If the following should occur during Diagnostic
Trouble Code (DTC) display, the display will be
discontinued. After initial check, the status that
is under the control of ABS will be returned :
– The vehicle starts (The wheels turn) or the
brake pedal is depressed.
Up to 3 different codes can be stored.
If the ABS should turn OFF due to an
intermittent defect, the system will be restored
at the next key cycle, if the initial check finds no
abnormality (when IGN is switched from OFF to
ON).
5. An example of DTC display
Display of DTC 23
B05R100001
After displaying DTC 12 three times, one DTC after
another is displayed. DTC is displayed on small
order.
C05L300017
The DTC 12 is displayed repeatedly.
Page 351 of 4264
BRAKE CONTROL SYSTEM 5A-35
Basic Diagnostic Flow Chart
RTW45AMF000101
Step Action Value(s) Yes No
1 1. Ignition “ON,”engine “OFF.”
2. Observe the ABS warning lamp.
Note: If a starter switch is turned ON, ABS warning
lamp will turn on and a ABS warning lamp will be
turned off after 3 seconds.
Is the ABS warning lamp “ON”?
- Go to Step 2 Go to “No
ABS warning
lamp”
2 1. Ignition “OFF.”
2. Install Tech2.
3. Ignition “ON.”
4. Attempt to display ABS data with the Tech 2.
Does the Tech 2 display ABS data?
- Go to Step 5 Go to Step 3
3 1. Ignition “OFF,” disconnect the EHCU.
2. Check the DLC (Data Link Connector) circuit for an
open, short to ground, or short to voltage.
Also, check the DLC ignition feed circuit for an
open or short to ground and the DLC ground circuit
for an open.
3. If a problem is found, repair as necessary.
Was a problem found?
- Go to Step 2 Go to Step 4
Page 352 of 4264
5A-36 BRAKE CONTROL SYSTEM
Step Action Value(s) Yes No
4 1. Check the EHCU circuit for an open, short to
ground, or short to voltage. Also, check the EHCU
ignition feed circuit for an open or short to ground
and the EHCU ground circuit for an open.
2. If a problem is found, repair as necessary.
Was a problem found?
- Go to Step 2 Go to Step 11
5 Select “Display DTCs” with the Tech 2.
Are any DTCs stored? - Go to Step 6 Go to Step 10
6 Review and record for Tech 2 Failure Records data
and DTCs.
Is the action complete? - Go to Step 7 -
7 Following the DTC is stored.
Is this DTC C0271 stored?
- Go to
applicable
DTC table
after Go to
step 8 Go to Step 8
8 Clear the DTCs by “Clear the Information“ with Tech
2.
Did the DTCs cleared? - Go to Step 9 -
9 Select “Display DTCs” with the Tech 2.
Are any DTCs stored?
- Go to
applicable
DTC table Go to Step 10
10 Review and record for Tech 2 data.
Is the action complete?
- Go to
Symptom
Diagnosis and
Go to Basic
Inspection
Procedure -
11 Replace the EHCU.
Note: Check the EHCU type for specification, when
the EHCU is replaced.
(Specification; 2WD Model or 4WD Model)
Is the action complete? - Verify repair -
