2004 ISUZU TF SERIES brake sensor

5B -20 ANTI-LOCK BRAKE SYSTEM

Special Tools

ILLUSTRATION PART NO.
PART NAME
ILLUSTRATION
PART NO.
PART NAME

5–8840–2789–0
Installer ; Sensor rotor,
front hub 9-8522-1271-0

Setting Tool
5-8840-0007-0

Grip

8A-278 ELECTRICAL-BODY AND CHASSIS
Low Fuel Indicator Light Inspection
1. Disconnect the fuel tank unit wire connector.
2. Turn the key switch on. Check that the bulb lights.
If operation is not correct, remove and check the bulb or circuit.
or If check whether low fuel turns on fuel input (B-24) at the
time of open and key on.
 meter is check at low fuel
140R300006





Check level sensor operation
1. Remove the fuel tank unit.
2.
Apply battery voltage between terminal (B) and (C) through
a 1.12 watt bulb. Check that the bulb lights.
Note:
It will take a short time for the bulb light.
3. Submerge the sensor in fuel. Check that the bulb goes out.
If operation is not correct, replace the fuel tank unit.

BRAKE SYSTEM WARNING LIGHT
The brake system warning light comes on while the parking
brake is set and the engine run position.
Note:
The parking brake indicator light circuit is designed to
prevent driving of the vehicle with the parking brake on.
It does not indicate the condition of the parking brake
system.



The parking brake switch is in parallel with the brake fluid
switch.



The brake system warning light also comes on when reservoir
brake fluid level falls below the specified limit with the parking
brake released and the engine run position.

ELECTRICAL-BODY AND CHASSIS 8A-423


No. Connector face No. Connector face
C-36
Silver
Engine room-LH ; Ground C-54
(6VE1)
(4JH1-TC)
OrangeABS sensor Front-LH
C-37
Black
Brake fluid level switch C-55
BrownThermo AMP
C-38
(4JH1-TC)
Vacuum switch C-56
(C24SE)
ECM
C-39

Parking brake switch (stick type) C-56
(4JA1-TC
4JH1-TC)
ECM-A
C-40
~
C-43 NOT USED C-57
(4JA1-TC
4JH1-TC)
ECM-B
C-44
White
Stop lamp switch C-58
~
C-62 NOT USED
C-45
~
C-49 NOT USED C-63
(6VE1)
(4JH1-TC)
Gray Front Fog lamp-RH
C-50

Condenser fan C-64
(6VE1)
(4JH1-TC)
Gray Front Fog lamp-LH
C-51
~
C-52 NOT USED C-65
~
C-66 NOT USED
C-53
(6VE1)
(4JH1-TC)
Orange ABS sensor Front-RH C-67
(6VE1)
(4JH1-TC)
BlackEHCU

6E–6 4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS
Circuit Description ..................................... 6E-268
Diagnostic Aids .......................................... 6E-268
Diagnostic Trouble Code (DTC) P0645
(Symptom Code 4) (Flash Code 46) A/C
Compressor Relay Circuit Voltage Low ... 6E-269
Diagnostic Trouble Code (DTC) P0645
(Symptom Code 8) (Flash Code 46) A/C
Compressor Relay Circuit Voltage High .. 6E-272
DIAGNOSTIC TROUBLE CODE (DTC) P0703
(SYMPTOM CODE A) (FLASH CODE 25)
BRAKE SWITCH CIRCUIT MALFUNCTION 6E-273
DIAGNOSTIC TROUBLE CODE (DTC) P0703
(SYMPTOM CODE B) (FLASH CODE 25)
BRAKE SWITCH CIRCUIT MALFUNCTION 6E-273
Circuit Description ..................................... 6E-274
Diagnostic Aids .......................................... 6E-274
Diagnostic Trouble Code (DTC) P0703
(Symptom Code A) (Flash Code 25) Brake
Switch Circuit Malfunction ....................... 6E-274
Diagnostic Trouble Code (DTC) P0703
(Symptom Code B) (Flash Code 25)
Brake Switch Circuit Malfunction ............. 6E-278
DIAGNOSTIC TROUBLE CODE (DTC) P0704
(SYMPTOM CODE 6) (FLASH CODE 57)
CLUTCH SWITCH INPUT CIRCUIT
MALFUNCTION ....................................... 6E-281
Circuit Description ..................................... 6E-281
Diagnostic Aids .......................................... 6E-281
Diagnostic Trouble Code (DTC) P0704
(Symptom Code 6) (Flash Code 57)
Clutch Switch Input Circuit Malfunction ... 6E-282
DIAGNOSTIC TROUBLE CODE (DTC) P1105
(SYMPTOM CODE 1) (FLASH CODE 86)
BAROMETRIC PRESSURE SENSOR
CIRCUIT HIGH INPUT ............................ 6E-285
DIAGNOSTIC TROUBLE CODE (DTC) P1105
(SYMPTOM CODE 2) (FLASH CODE 86)
BAROMETRIC PRESSURE SENSOR
CIRCUIT LOW INPUT ............................. 6E-285
Circuit Description ..................................... 6E-285
Diagnostic Aids .......................................... 6E-285
Diagnostic Trouble Code (DTC) P1105
(Symptom Code 1) (Flash Code 86) Barometric
Pressure Sensor Circuit High Input ......... 6E-285
Diagnostic Trouble Code (DTC) P1105
(Symptom Code 2) (Flash Code 86) Barometric
Pressure Sensor Circuit Low Input .......... 6E-285
DIAGNOSTIC TROUBLE CODE (DTC) P1120
(SYMPTOM CODE 1) (FLASH CODE 21)
PEDAL/THROTTLE POSITION SENSOR
CIRCUIT HIGH INPUT ............................ 6E-287
DIAGNOSTIC TROUBLE CODE (DTC) P1120
(SYMPTOM CODE 7) (FLASH CODE 21)PEDAL/THROTTLE POSITION SENSOR
VOLTAGE SUPPLY CIRCUIT HIGH INPUT 6E-287
DIAGNOSTIC TROUBLE CODE (DTC) P1120
(SYMPTOM CODE 9) (FLASH CODE 21)
PEDAL/THROTTLE POSITION SENSOR
VOLTAGE SUPPLY CIRCUIT LOW INPUT 6E-287
DIAGNOSTIC TROUBLE CODE (DTC) P1120
(SYMPTOM CODE D) (FLASH CODE 21)
PEDAL/THROTTLE POSITION SENSOR
BRAKE SWITCH ERROR ....................... 6E-287
DIAGNOSTIC TROUBLE CODE (DTC) P1120
(SYMPTOM CODE E) (FLASH CODE 21)
PEDAL/THROTTLE POSITION SENSOR
IDLE POSITION SWITCH ERROR ......... 6E-287
Circuit Description ...................................... 6E-288
Diagnostic Aids .......................................... 6E-288
Diagnostic Trouble Code (DTC) P1120
(Symptom Code 1) (Flash Code 21)
Pedal/Throttle Position Sensor
Circuit High Input ..................................... 6E-288
Diagnostic Trouble Code (DTC) P1120
(Symptom Code 7) (Flash Code 21)
Pedal/Throttle Position Sensor Voltage
Supply Circuit High Input ......................... 6E-293
Diagnostic Trouble Code (DTC) P1120
(Symptom Code 9) (Flash Code 21)
Pedal/Throttle Position Sensor Voltage
Supply Circuit Low Input .......................... 6E-295
Diagnostic Trouble Code (DTC) P1120
(Symptom Code D) (Flash Code 21)
Pedal/Throttle Position Sensor Brake
Switch Error ............................................. 6E-298
Diagnostic Trouble Code (DTC) P1120
(Symptom Code E) (Flash Code 21)
Pedal/Throttle Position Sensor Idle
Position Switch Error ............................... 6E-300
DIAGNOSTIC TROUBLE CODE (DTC) P1173
(SYMPTOM CODE 3) (FLASH CODE 22) FUEL
REDUCTION CAUSED BY HIGH COOLANT
TEMPERATURE ...................................... 6E-302
DIAGNOSTIC TROUBLE CODE (DTC) P1173
(SYMPTOM CODE 7) (FLASH CODE 22) FUEL
REDUCTION CAUSED BY HIGH FUEL
TEMPERATURE ...................................... 6E-302
DIAGNOSTIC TROUBLE CODE (DTC) P1173
(SYMPTOM CODE A) (FLASH CODE 22) FUEL
REDUCTION CAUSED BY LOW FUEL
TEMPERATURE ...................................... 6E-302
Circuit Description ...................................... 6E-302
Diagnostic Aids .......................................... 6E-302
Diagnostic Trouble Code (DTC) P1173
(Symptom Code 3) (Flash Code 22) Fuel
Reduction Caused By High Coolant

6E–88 4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS
TYPICAL SCAN DATA & DEFINITIONS (ENGINE DATA)
4JA 1-TC ENGINE
Use the typical values table only after the On-Board Diagnostic System check has been completed, no DTC(s) were
noted, and you have determined that the On-Board Diagnostic are functioning properly.
Tech2 values from a properly running engine may be used for comparison with the engine you are diagnosing.
Condition : Vehicle stopping, engine running, air conditioning off & after warm-up (Coolant temperature approx imately
80 deg. C)
Tech 2 Parameter Units Idle 1500rpm 2000rpm Description
1 Engine Speed rpm 730 1475 -
15251975 -
2025The engine speed is measured by ECM from the CKP
se nso r.
2 Vehicle Speed km/h / MPH 0 0 0 This displays vehicle speed. The vehicle speed is
measured by ECM from the vehicle speed sensor.
3 Pump Spe ed rpm 345 - 385 725 - 775 975 - 1025 This displa ys injectio n pump spe ed. The inje ction spe ed is
measured by ECM from the pump cam sensor.
4 Accelerator Position
Sensor Signal% 0 4 - 6 6 - 8 Throttle position operating angle is measured by the ECM
fro m throttle po sition o utput v olta ge . This sho uld display
0% a t idle a nd 99 - 100% a t full thro ttle .
5 Idle Switch Activ e /
Inactive 0VActive Active Inactive 0V This displays operating status of the idle switch. This
should display "Active" until the accelerator position nearly
4 - 5%.
6 Mass Air Flow
Sensormg/strk 380 - 420 360 - 400 380 - 420 This displays calculated intake air volume for one cylinder
stroke. The mass air flow is measured by ECM from the
MAF sensor output voltage.
7 Desire d Ma ss Air
Flo wmg/strk 350 350 350 - 370 This displays desired intake air volume for one cylinder
stroke. The desired mass air flow is calculated by ECM
de pe nding on engine conditio n.
8 Baro metric Pre ssure hpa De pe nds
on altitudeDe pe nds
o n a ltitudeDe pe nds
on altitudeThe ba rome tric pre ssure is mea sure d by ECM from the
sensor in the ECM. This data is changing by altitude.
9 Desired Injection
Qua ntitymg/stk 8 - 10 6 - 10 7 - 10 This displays desired value from the ECM. The ECM
co mpe nsates fo r fue l ra te to ba sic ra te.
10 Injection Qua ntity mg/stk 8 - 10 5 - 10 5 - 9 This displa y s ca lculated a ctua l fue l qua ntity from the PSG.
The PSG receives desired injection quantity from the ECM.
And, it compensates actual injection depending on timer
po sitio n to de termine duration o f the high pre ssure
solenoid valve operation.
11 Desire d Fuel Injection
St a r tde g. CA 2 - 4 2- 5 3 - 5 This display s de sired injection timing from the ECM. The
ECM compensates for fuel injection timing by throttle
position and various sensor signal.
12 Actua l Injectio n Sta rt de g. CA 2 - 4 2 - 5 3 - 5 This display s ca lculate d a ctua l inje ctio n timing ba se d o n
CKP signa l a nd pump ca m signal. The PSG controls TCV
duty ra tio to mee t desired inje ctio n timing from the ECM.
13 Coolant Temperature deg. C / deg.
F80 - 85 80 - 85 80 - 85 The ECT is measured by ECM from ECT sensor output
voltage. This data is changing by coolant temperature.
When the engine is normally warm upped, this data
displays approximately 80 deg. C.
14 Fuel Temperature deg. C / deg.
FDe pe nds
on fuel
temp.De pe nds
on fuel
te mp.De pe nds
on fuel
te mp.The FT is measured by PSG from FT sensor. This data is
changing by fuel temperature.
15 Inta ke Air
Temperaturedeg. C / deg.
FDe pe nds
on ambient
temp.De pe nds
on ambient
te mp.De pe nds
on ambient
te mp.The IAT is measured by ECM from IAT sensor output
voltage. This data is changing by intake air temperature.
16 Ignition Status On12V/
Off0VOn 12V On 12V On 12V This displays the key switch status indicated by the ECM
with key switch signal. This should display "Off 0V" at key
OFF and "On12V" at key ON.
17 Brake Switch 1 Active/
InactiveInactive Inactive Inactive This displays operating status of the brake switch. This
should display "Active" when the brake pedal is stepped
on.

6E–90 4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS
TYPICAL SCAN DATA & DEFINITIONS (ENGINE DATA)
4JH1-TC ENGINE
Use the typical values table only after the On-Board Diagnostic System check has been completed, no DTC(s) were
noted, and you have determined that the On-Board Diagnostic are functioning properly.
Tech2 values from a properly running engine may be used for comparison with the engine you are diagnosing.
Condition : Vehicle stopping, engine running, air conditioning off & after warm-up (Coolant temperature approx imately
80 deg. C)
Tech 2 Parameter Units Idle 1500rpm 2000rpm Definition
1 Engine Speed rpm 675 - 725 1475 -
15251975 -
2025The engine speed is measured by ECM from the CKP
se nso r.
2 Vehicle Speed km/h / MPH 0 0 0 This displays vehicle speed. The vehicle speed is
measured by ECM from the vehicle speed sensor.
3 Pump Spe ed rpm 335 - 375 725 - 775 975 - 1025 This displa ys injectio n pump spe ed. The inje ction spe ed is
measured by ECM from the pump cam sensor.
4 Accelerator Position
Sensor Signal% 0 3 - 5 5 - 7 Throttle position operating angle is measured by the ECM
fro m throttle po sition o utput v olta ge . This sho uld display
0% a t idle a nd 99 - 100% a t full throttle .
5 Idle Switch Activ e /
Inactive 0VActive Active/
Inactive 0VInactive 0V This displays operating status of the idle switch. This
should display "Active" until the accelerator position nearly
4 - 5%.
6 Mass Air Flow
Sensormg/strk 420 - 490 380 - 460 410 - 480 This displays calculated intake air volume for one cylinder
stroke. The mass air flow is measured by ECM from the
MAF sensor output voltage.
7 Desire d Ma ss Air
Flo wmg/strk 430 - 470 380 - 420 410 - 470 This displays desired intake air volume for one cylinder
stroke. The desired mass air flow is calculated by ECM
de pe nding on engine conditio n.
8 Baro metric Pre ssure hpa De pe nds
on altitudeDe pe nds
o n a ltitudeDe pe nds
on altitudeThe ba rome tric pre ssure is mea sure d by ECM from the
sensor in the ECM. This data is changing by altitude.
9 Desired Injection
Qua ntitymg/stk 6 - 10 6 - 10 7 - 11 This displays desired value from the ECM. The ECM
co mpe nsates for fuel rate by thro ttle po sition a nd va rio us
se nso r signa ls.
10 Injection Qua ntity mg/stk 6 - 10 6 - 10 7 - 11 This displa y s ca lculated a ctua l fue l qua ntity from the PSG.
The PSG receives desired injection quantity from the ECM.
And, it compensates actual injection depending on timer
po sitio n to de termine duration o f the high pre ssure
solenoid valve operation.
11 Desire d Fuel Injection
St a r tde g. CA 1 - 3 2 - 4 3 - 5 This display s de sired injection timing from the ECM. The
ECM compensates for fuel injection timing by throttle
position and various sensor signal.
12 Actua l Injectio n Sta rt de g. CA 1 - 3 2 - 4 3 - 5 This display s ca lculate d a ctua l inje ctio n timing ba se d o n
CKP signa l a nd pump ca m signal. The PSG controls TCV
duty ra tio to mee t desired inje ctio n timing from the ECM.
13 Coolant Temperature deg. C / deg.
F80 - 85 80 - 85 80 - 85 The ECT is measured by ECM from ECT sensor output
voltage. This data is changing by coolant temperature.
When the engine is normally warm upped, this data
displays approximately 80 deg. C.
14 Fuel Temperature deg. C / deg.
FDe pe nds
on fuel
temp.De pe nds
on fuel
te mp.De pe nds
on fuel
te mp.The FT is measured by PSG from FT sensor. This data is
changing by fuel temperature.
15 Inta ke Air
Temperaturedeg. C / deg.
FDe pe nds
on ambient
temp.De pe nds
on ambient
te mp.De pe nds
on ambient
te mp.The IAT is measured by ECM from IAT sensor output
voltage. This data is changing by intake air temperature.
16 Ignition Status On12V/
Off0VOn 12V On 12V On 12V This displays the key switch status indicated by the ECM
with key switch signal. This should display "Off 0V" at key
OFF and "On12V" at key ON.
17 Brake Switch 1 Active/
InactiveInactive Inactive Inactive This displays operating status of the brake switch. This
should display "Active" when the brake pedal is stepped
on.

4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS 6E–123
46 P0645 4 ON A/C Compressor Relay
Circuit Voltage LowA/C compressor relay circuit
open or short to ground
circuit.No fail-safe function. A/C compressor relay circuit
is correct condition.1. A/C compressor relay
circuit open or short to
g r o u n d c i r c u i t .
2. Poor connector
c o n n e c t i o n .
3. A/C compressor relay
m a l f u n c t i o n .
4. ECM malfunction.41 —
8 ON A/C Compressor Relay
Circuit Voltage High A/C compressor relay circuit
short to voltage circuit.ECM malfunction.
——
25 P0703 A ON Brake Switch Circuit
Malfunction1. Throttle position is more
t h a n 0 % .
2. Engine speed is more
than 693rpm (4JA1-TC)
or 665rpm (4JH1-TC).
3. Vehicle speed is more
t h a n 0 k m / h .
4. Brake switch 1 signal and
brake switch 2 signal are
differently inputted to the
ECM since the ignition
switch was turned on.No fail-safe function. Brake switch 1 signal and
brake switch 2 signal are
correctly inputted to the
ECM.1. Brake switch 1 circuit
open, short to ground or
short to voltage circuit.
2. Poor connector
c o n n e c t i o n .
3. Brake switch 1
m a l f u n c t i o n .
4. ECM malfunction.30 —
B ON Brake Switch Circuit
Malfunction1. Throttle position is more
t h a n 0 % .
2. Engine speed is more
than 693rpm (4JA1-TC)
or 665rpm (4JH1-TC).
3. Vehicle speed is more
t h a n 0 k m / h .
4. Brake switch 1 signal and
brake switch 2 signal are
differently inputted to the
ECM.1. Brake switch 2 circuit
open or short to ground
c i r c u i t .
2. Poor connector
c o n n e c t i o n .
3. Brake switch 2
m a l f u n c t i o n .
4. ECM malfunction.65 —
57 P0704 6 ON Clutch Switch Input Circuit
MalfunctionClutch signal does not
change between vehicle
speed 1.5km/h and 80km/h
since ignition switch was
tuned on. No fail-safe function. Clutch signal correctly
changes.1. Clutch switch circuit
open, short to ground or
short to voltage circuit.
2. Poor connector
c o n n e c t i o n .
3. Clutch switch
m a l f u n c t i o n .
4. ECM malfunction.31 — —
86 P1105 1 ON Barometric Pressure Sensor
Circuit High InputBarometric pressure sensor
output voltage is more than
4.4V.ECM uses 1013hpa
condition as substitute.Barometric pressure sensor
output voltage is below 4.4V.ECM malfunction.
——
2 ON Barometric Pressure Sensor
Circuit Low InputBarometric pressure sensor
output voltage is below 1.5V.Barometric pressure sensor
output voltage is more than
1.5V.ECM malfunction.
—— Flash
CodeCodeSymptom
CodeMILDTC Name DTC Setting Condition Fail-Safe (Back Up) Recovery Condition Related Failure PartsRelated
ECM Pin
No.Related
Multiple
DTC4JA1-TC
(MT)4JH1-TC
(MT)4JH1-TC
(AT)

6E–124 4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS
21 P1120 1 ON Pedal/Throttle Position
Sensor Circuit High InputThrottle position sensor
output voltage is more than
4.5V.ECM increases idle speed up
to 1400rpm.Throttle position sensor
output voltage is below 4.5V.1. Sensor power supply
circuit short to voltage
c i r c u i t .
2. Sensor signal circuit
short to voltage circuit.
3. Sensor ground circuit
open or short to voltage
c i r c u i t .
4. Poor connector
c o n n e c t i o n .
5 . T P S m a l f u n c t i o n .
6. ECM malfunction.3 8 /
4 9 /
57—
7 ON Pedal/Throttle Position
Sensor Voltage Supply
Circuit High InputThrottle position sensor
power supply voltage is more
than 5.2V.Throttle position sensor
power supply voltage is
below 5.2V.1. Sensor power supply
circuit short to battery
voltage circuit.
2 . T P S m a l f u n c t i o n .
3. ECM malfunction.57 —
9 ON Pedal/Throttle Position
Sensor Voltage Supply
Circuit Low InputThrottle position sensor
power supply voltage is
below 4.6V.Throttle position sensor
power supply voltage is more
than 4.6V.1. Sensor power supply
circuit short to ground
c i r c u i t .
2 . T P S m a l f u n c t i o n .
3. ECM malfunction.57 —
D ON Pedal/Throttle Position
Sensor Brake Switch Error1. Engine speed is more
t h a n 1 7 0 0 r p m .
2. Vehicle speed is more
t h a n 1 . 5 k m / h .
3. When brake pedal is
depressed during
accelerator pedal is
d e p r e s s i n g . Throttle position is more than
20% or brake pedal is
released (switch is inactive). 1 . T h r o t t l e s t i c k i n g .
2. TPS incorrect adjusting.
3 . T P S m a l f u n c t i o n .
4. Brake switch
m a l f u n c t i o n .
5. ECM malfunction.3 0 /
3 8 /
65—
E ON Pedal/Throttle Position
Sensor Idle Position Switch
Error1. When idle switch is
turned off, throttle
position sensor was
b e l o w 0 . 3 5 % .
o r
2. When idle switch is tuned
on, throttle position
sensor was more than
7.8%.1. When throttle position
sensor is 100%, idle
s w i t c h t u r n s o f f .
2. When throttle position
sensor is 0%, idle switch
turns on.1 . T P S m a l f u n c t i o n .
2. Idle switch malfunction.
3. ECM malfunction.
3 8 /
69—
22 P1173 3 OFF Fuel Reduction Caused By
High Coolant TemperatureExcessive high engine
coolant temperature is
detected.No fail-safe function. Engine coolant temperature
is normal range.1 . E n g i n e o v e r h e a t .
2. ECT sensor malfunction.








3. ECM malfunction.89 —
7 OFF Fuel Reduction Caused By
High Fuel TemperatureFuel temperature is more
than 100 deg. C.PSG (pump control unit)
controls fuel injection
quantity based on engine
speed and fuel temperature.Fuel temperature is below
100 deg. C.1 . E C M m a l f u n c t i o n .
2. PSG (pump control unit)
malfunction.——
A OFF Fuel Reduction Caused By
Low Fuel TemperatureExcessive low fuel
temperature is detected.No fail-safe function. Fuel temperature is normal
range.1 . E C M m a l f u n c t i o n .
2. PSG (pump control unit)
malfunction.——— Flash
CodeCodeSymptom
CodeMILDTC Name DTC Setting Condition Fail-Safe (Back Up) Recovery Condition Related Failure PartsRelated
ECM Pin
No.Related
Multiple
DTC4JA1-TC
(MT)4JH1-TC
(MT)4JH1-TC
(AT)