2004 ISUZU TF SERIES engine coolant

4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS 6E–89
18 Brake Switch 2 Active/
InactiveInactive Inactive Inactive This displays operating status of the brake switch. This
should display "Active" when the brake pedal is stepped
on.
19 Clutch Sw itch Activ e /
InactiveInactive Inactive Inactive This displays operating status of the clutch switch. This
should display "Active" when the clutch pedal is stepped
on.
20 Neutra l Switch On/Off On On On This displa ys o pe rating status of the neutra l switch. This
should display "On" when the gear position is neutral.
21 A/C Informa tion
SwitchActive 12V/
Inactive 0VInactive 0V Inactive 0V Inactive 0V This displays the air conditioner request signal. This
should display "Active 12V" when the air conditioner switch
is switched on.
22 Dia gnostic Re quest Activ e 0V/
Inactive 12VIna ctiv e
12VInactive
12VIna ctiv e
12VThis display s the dia gnostic reque st signal. This sho uld
display "Inactive 12V" when the Tech 2 is connected.
23 System Voltage V 10 - 14 10 - 14 10 - 14 This displays the system voltage measured by the ECM at
ignition feed.
24 Ma in Re la y Activ e /
InactiveActive Active Active This displays operating status for the ECM main relay. This
should display "Active" when the key switch is turned on
and while engine is running.
25 Glow Time Relay Activ e 0V/
Inactive12VIna ctiv e
12VInactive
12VIna ctiv e
12VThis displays operating status for the glow relay. This
should display "Inactive 12V" when the engine is warm
uppe d.
26 Check Engine Light On/Off Off Off Off This displays operating status for the Check Engine Lamp.
This should display "On" when the Check Engine Lamp is
turned on.
27 Glow Time Telltale On/Off Off Off Off This displays operating status for the glow indicator lamp.
This sho uld display "On" whe n the glo w la mp is turne d o n.
28 Desired Engine Idle
Speedrpm 730 730 730 The desired engine idle speed that the ECM commanding.
The ECM compensates for various engine loads based on
engine coolant temperature.
29 A/C Re que st Activ e 0V/
Inactive 12VIna ctiv e
12VInactive
12VIna ctiv e
12VThis displays operating status of the A/C compressor. This
should display "Active 0V" when the compressor relay is
operated.
30 Immo bilize r Activ e /
InactiveInactive Inactive Inactive This should display "Inactive" when the immobilizer is
correctly operated.
31 Immo bilize r Signal Rece iv ed/
Not
Rece iv edNo t
Receive dNo t
Re ceive dNot
Re ce iv e dThis sho uld displa y "No t Receive d" whe n the immo bilize r is
not activated.
32 Immo bilize r Function
ProgrammedYes/ No Yes Yes Yes This should display "Yes" when the immobilizer is correctly
programmed.
33 EGR Pulse Ratio
(Ex ha ust Ga s
Recirculatio n)% 70 70 70 This displays the duty signal from the ECM to control the
EGR flow amount. Tech 2 Parameter Units Idle 1500rpm 2000rpm Description

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–91
18 Brake Switch 2 Active/
InactiveInactive Inactive Inactive This displays operating status of the brake switch. This
should display "Active" when the brake pedal is stepped
on.
19 Clutch Switch (M/T
On ly )Active/
InactiveInactive Inactive Inactive This displays operating status of the clutch switch. This
should display "Active" when the clutch pedal is stepped
on.
20 Neutra l Switch On/Off On On On This displa ys o pe rating status of the neutra l switch. This
should display "On" when the gear position is neutral (M/T)
or P, N positio n (A/T).
21 A/C Informa tion
SwitchActive 12V/
Inactive 0VInactive 0V Inactive 0V Inactive 0V This displays the air conditioner request signal. This
should display "Active 12V" when the air conditioner switch
is switched on.
22 Dia gnostic Re quest Activ e 0V/
Inactive 12VIna ctiv e
12VInactive
12VIna ctiv e
12VThis displays the diagnostic request signal. This should
display "Inactive 12V" when the Tech 2 is connected.
23 System Voltage V 10 - 15 10 - 15 10 - 15 This displays the system voltage measured by the ECM at
ignition feed.
24 Ma in Re la y Activ e /
InactiveActive Active Active This displays operating status for the ECM main relay. This
should display "Active" when the key switch is turned on
and while engine is running.
25 Glow Time Relay Activ e 0V/
Inactive12VIna ctiv e
12VInactive
12VIna ctiv e
12VThis displays operating status for the glow relay. This
should display "Inactive 12V" when the engine is warm
uppe d.
26 Check Engine Light On/Off Off Off Off This displays operating status for the Check Engine Lamp.
This should display "On" when the Check Engine Lamp is
turned on.
27 Glow Time Telltale On/Off Off Off Off This displays operating status for the glow indicator lamp.
This sho uld display "On" whe n the glo w la mp is turne d o n.
28 Desired Engine Idle
Speedrpm 700 700 700 The desired engine idle speed that the ECM commanding.
The ECM compensates for various engine loads based on
engine coolant temperature.
29 A/C Re que st Activ e 0V/
Inactive 12VIna ctiv e
12VInactive
12VIna ctiv e
12VThis displays operating status of the A/C compressor. This
should display "Active 0V" when the compressor relay is
operated.
30 Immo bilize r Activ e /
InactiveInactive Inactive Inactive This should display "Inactive" when the immobilizer is
correctly operated.
31 Immo bilize r Signal Rece iv ed/
Not
Rece iv edNo t
Receive dNot
Re ceive dNot
Re ce iv e dThis sho uld displa y "No t Receive d" whe n the immo bilize r is
not activated.
32 Immo bilize r Function
ProgrammedYes/ No Yes Yes Yes This should display "Yes" when the immobilizer is correctly
programmed.
33 EGR Pulse Ratio
(Ex ha ust Ga s
Recirculatio n)% 85 - 90 85 - 90 85 - 90 This displays the duty signal from the ECM to control the
EGR flow amount. Tech 2 Parameter Units Idle 1500rpm 2000rpm Definition

4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS 6E–115
34 P0105 7 ON Vacuum Pressure Sensor
Voltage Supply Circuit High
InputVacuum sensor power
supply voltage is more than
5.2V.1. Fuel injection quantity is
r e d u c e d .
2. ECM use vacuum sensor
output voltage 5.0V
condition as substitute.Vacuum sensor power
supply voltage is below 5.2V.1. Sensor power supply
circuit short to battery
voltage circuit.
2. Vacuum sensor
m a l f u n c t i o n .
3. ECM malfunction.82 — —
9 ON Vacuum Pressure Sensor
Voltage Supply Circuit Low
InputVacuum sensor power
supply voltage is below 4.5V.Vacuum sensor power
supply voltage is more than
4.5V.1. Sensor power supply
circuit short to ground
c i r c u i t .
2. Vacuum sensor
m a l f u n c t i o n .
3. ECM malfunction.82 — —
23 P0110 1 ON Intake Air Temperature (IAT)
Sensor Circuit High InputIAT sensor output voltage is
more than 4.7V.ECM use 0 deg. C conditions
as substitute.IAT sensor output voltage is
below 4.7V.1. Sensor signal circuit
open or short to voltage
c i r c u i t .
2. Sensor ground circuit
open or short to voltage
c i r c u i t .
3. Poor connector
c o n n e c t i o n
4. IAT sensor malfunction.
5. ECM malfunction.8 4 /
92P0100(B)/







P0100(C)
2 ON Intake Air Temperature (IAT)
Sensor Circuit Low InputIAT sensor output voltage is
below 0.3V.IAT sensor output voltage is
more than 0.3V.1. Sensor signal circuit
short to ground circuit.
2. IAT sensor malfunction.
3. ECM malfunction.84 —
14 P0115 1 ON Engine Coolant Temperature
(ECT) Sensor Circuit High
InputECT sensor output voltage is
more than 4.7V.1. ECM uses fuel
temperature as
s u b s t i t u t e .
2. ECM uses 60 deg. C
condition for injection
t i m i n g c o n t r o l .
3. ECM uses -25 deg. C
condition (4JA1-TC) or -
15 deg. C condition
(4JH1-TC) for glow time
control.ECT sensor output voltage is
below 4.7V.1. Sensor signal circuit
open or short to voltage
c i r c u i t .
2. Sensor ground circuit
open or short to voltage
c i r c u i t .
3. Poor connector
c o n n e c t i o n
4. ECT sensor malfunction.
5. ECM malfunction.8 9 /
93P0105(1)
2 ON Engine Coolant Temperature
(ECT) Sensor Circuit Low
InputECT sensor output voltage is
below 0.3V.ECT sensor output voltage is
more than 0.3V.1. Sensor signal circuit
short to ground circuit.
2. ECT sensor malfunction.
3. ECM malfunction.89 —
15 P0180 B ON Fuel Temperature Sensor
Circuit Range/PerformanceFT sensor output is high
temperature (more than 150
deg. C) or low temperature
(below -40 deg. C).The ECM use 75 deg. C
conditions as substitute.FT sensor output is correct
temperature range between
150 deg. C and -40 deg. C.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)

4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS 6E–117
64 P0243 3 ON Turbocharger Wastegate
Solenoid "A" Range/
Performance1. Intake air temperature is
between -50 deg. C and
2 0 0 d e g . C .
2. Engine coolant
temperature is between -
50 deg. C and 150 deg.
C .
3. Barometric pressure is
between 0hpa and
3 5 0 0 h p a .
4. Low vacuum pressure
condition. (Desired
vacuum pressure - actual
vacuum pressure is more
than 50hpa.)1. Fuel injection quantity is
r e d u c e d .
2. EGR EVRV becomes
1 0 % c o n d i t i o n . 1. Engine speed is between
500rpm and 6000rpm.
2. Correct vacuum pressure
condition. (Desired
vacuum pressure - actual
vacuum pressure is less
than 50hpa.)1. Turbocharger wastegate
control EVRV
m a l f u n c t i o n .
2. Vacuum line is
o b s t r u c t e d .
3. Vacuum is leaking.
4. Vacuum pump
m a l f u n c t i o n .
5. Vacuum sensor
m a l f u n c t i o n .
6. Turbocahrger wastegate
v a l v e m a l f u n c t i o n .
7. ECM malfunction.8 5 /
96——
4 ON Turbocharger Wastegate
Solenoid "A" Low Wastegate control EVRV
circuit open or short to
ground circuit.1. Fuel injection quantity is
r e d u c e d .
2. EGR EVRV becomes
1 0 % c o n d i t i o n .
3. Wastegate control EVRV
becomes 32% condition.Wastegate control EVRV
circuit is correct condition.1. Wastegate control EVRV
circuit open or short to
g r o u n d c i r c u i t .
2. Wastegate control EVRV
m a l f u n c t i o n .
3. ECM malfunction.96 — —
5 ON Turbocharger Wastegate
Solenoid "A" Range/
Performance1. Intake air temperature is
between -50 deg. C and
2 0 0 d e g . C .
2. Engine coolant
temperature is between -
50 deg. C and 150 deg.
C .
3. Barometric pressure is
between 0hpa and
3 5 0 0 h p a .
4. High vacuum pressure
condition. (Desired
vacuum pressure - actual
vacuum pressure is less
than -50hpa.)1. Fuel injection quantity is
r e d u c e d .
2. EGR EVRV becomes
1 0 % c o n d i t i o n . 1. Engine speed is between
500rpm and 6000rpm.
2. Correct vacuum pressure
condition. (Desired
vacuum pressure - actual
vacuum pressure is more
than -50hpa.)1. Turbocharger wastegate
control EVRV
m a l f u n c t i o n .
2. Vacuum regulating valve
m a l f u n c t i o n .
3. Vacuum pump
m a l f u n c t i o n .
4. Vacuum sensor
m a l f u n c t i o n .
5. ECM malfunction.8 5 /
96——
6 ON Turbocharger Wastegate
Solenoid "A" Malfunction1. Engine coolant
temperature is between -
50 deg. C and 150 deg.
C .
2. EGR control EVRV 0%
c o n d i t i o n .
3. No DTC relating to MAF
sensor, vacuum sensor &
I A T s e n s o r .
4. Large amount of mass air
flow. (= Incorrect boost
pressure condition)
(Desired mass air flow -
actual mass air flow is
less than -56mg/strk.)1. Correct amount of mass
air flow. (= Correct boost
pressure condition)
(Desired mass air flow -
actual mass air flow is
more than -56mg/strk.)1. Turbocharger wastegate
a c t u a t o r m a l f u n c t i o n .
2. Vacuum line malfunction.

































3. 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–120 4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS
67 P0381 4 ON Glow Plug Indicator Circuit
Voltage LowGlow plug indicator circuit
open or short to ground
circuit.No fail-safe function. Glow plug indicator circuit is
correct condition.1. Glow plug indicator
circuit open or short to
g r o u n d c i r c u i t .
2. Glow plug indicator lamp
m a l f u n c t i o n .
3. ECM malfunction.43 —
8 ON Glow Plug Indicator Circuit
Voltage HighGlow plug indicator circuit
short to voltage circuit.ECM malfunction.
——
32 P0400 3 ON Exhaust Gas Recirculation
Flow Excessive Detected1. Intake air temperature is
between 15 deg. C and
1 0 0 d e g . C .
2. Engine coolant
temperature is between
55 deg. C and 100 deg.
C (4JA1-TC) or 35 deg. C
and 100 deg. C (4JH1-
T C ) .
3. Barometric pressure is
between 850hpa and
1 1 0 0 h p a .
4. Small amount of mass air
flow. (Desired mass air
flow - mass air flow is
more than 150mg/strk)Fuel injection quantity is
reduced. 1. Engine speed is between
1500rpm and 3100rpm
(4JA1-TC) or 1500rpm
and 3200rpm (4JH1-TC).



















2. Injection quantity is
below 32mg/strk (4JA1-
TC) or 40mg/stk (4JH1-
T C ) .
3. Correct amount of mass
air flow.1. EGR valve is stuck at
o p e n p o s i t i o n .
2. EGR EVRV malfunction.
3 . A i r i n t a k e i s o b s t r u c t e d .
4. Air intake is leaking.
5. MAF sensor malfunction.
6. ECM malfunction.
8 8 /
97—
4 ON Exhaust Gas Recirculation
Circuit Short to Ground or
Open CircuitEGR EVRV circuit open or
short to ground circuit.Fuel injection quantity is
reduced and EGR EVRV
10% conditions as substitute.EGR EVRV circuit is correct
condition.1. EGR EVRV circuit open
or short to ground circuit.
2. EGR EVRV malfunction.
3. ECM malfunction.97 —
5 ON Exhaust Gas Recirculation
Flow Insufficient Detected1. Intake air temperature is
between 15 deg. C and
100 deg. C.
2. Engine coolant
temperature is between
55 deg. C and 100 deg.
C (4JA1-TC) or 35 deg. C
and 100 deg. C (4JH1-
T C ) .
3. Barometric pressure is
between 850hpa and
1 1 0 0 h p a .
4. Large mount of mass air
flow. (Desired mass air
flow - mass air flow is
below -150 mg/strk)Fuel injection quantity is
reduced. 1. Engine speed is between
1500rpm and 3100rpm
(4JA1-TC) or 1500rpm
and 3200rpm (4JH1-TC).



















2. Injection quantity is
below 32mg/strk (4JA1-
TC) or 40mg/stk (4JH1-
T C ) .
3. Correct amount of mass
air flow.1. EGR valve is stuck at
c l o s e p o s i t i o n .
2. EGR valve operating
vacuum hose is clogged
or disconnected.
3. EGR EVRV malfunction.


4. MAF sensor signal circuit
short to voltage circuit.
5. MAF sensor malfunction.
6. ECM malfunction.8 8 /
97—
8 ON Exhaust Gas Recirculation
Circuit Short to BatteryEGR EVRV circuit short to
voltage circuit.Fuel injection quantity is
reduced & EGR EVRV 10%
conditions as substitute.EGR EVRV circuit is correct
condition.1. EGR EVRV circuit short
t o v o l t a g e c i r c u i t .
2. EGR EVRV malfunction.
3. ECM malfunction.97 — 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)

6E–160 4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS
DIAGNOSTIC TROUBLE CODE (DTC) P0115 (SYMPTOM CODE 1)
(FLASH CODE 14) ENGINE COOLANT TEMPERATURE SENSOR CIRCUIT
HIGH INPUT
DIAGNOSTIC TROUBLE CODE (DTC) P0115 (SYMPTOM CODE 2)
(FLASH CODE 14) ENGINE COOLANT TEMPERATURE SENSOR CIRCUIT LOW
INPUT
Condition for setting the DTC and action taken when the DTC sets
Circuit Description
The ECT sensor is a thermistor. A temperature changesthe resistance value. And it changes voltage. In other
words it measures a temperature value. It is installed on
the coolant stream. Low coolant temperature produces
Flash
CodeCode Symptom
CodeMIL DTC Name DTC Setting Condition Fail-Safe (Back Up)
14 P0115 1 ON Engine Coolant Temperature
(ECT) Se nsor Circuit High
InputECT sensor output voltage is
more than 4.7V.1. ECM uses fue l te mpe rature
as substitute.
2. ECM uses 60 de g.C
condition for injection timing
contro l.
3. ECM uses -25 de g.C
condition (4JA1-TC) or -15
deg.C condition (4JH1-TC)
for glo w time co ntro l. 2 ON Engine Coolant Temperature
(ECT) Se nsor Circuit Low
InputECT sensor output voltage is
be lo w 0.3V.