Fuel sensor ISUZU TF SERIES 2004 Owner's Guide

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)

4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS 6E–121
24 P0500 1 ON
at
next
igniti
on
cycleVehicle Speed Sensor Circuit
High InputVehicle speed is more than
200km/h.ECM uses vehicle speed
5km/h condition as
substitute.Vehicle speed is below
200km/h.1. VSS signal circuit open,
short to ground or short
t o v o l t a g e c i r c u i t .
2. VSS malfunction.
3. Speed meter
m a l f u n c t i o n .
4. TCM malfunction (AT
2 W D ) .
5. ECM malfunction.68 —
A O N
at
next
igniti
on
cycleVehicle Speed Sensor Input
Signal Frequency Too HighInput signal frequency is too
high.ECM uses vehicle speed
5km/h condition as
substitute.Correct vehicle speed signal
frequency. 1. VSS malfunction.
2. Speed meter
m a l f u n c t i o n .
3. Electrical interference.
4. Magnetic interference.
5. ECM malfunction.68 —
B O N
at
next
igniti
on
cycleVehicle Speed Sensor
Incorrect Signal1. Engine speed is more
than 3200rpm (4JA1-TC)
or 3600rpm (4JH1-TC).
2. Fuel injection quantity is
more than 30mg/strk
(4JA1-TC) or 41mg/strk
( 4 J H 1 - T C ) .
3. Vehicle speed is below
1.5km/h.Fuel injection quantity is
reduced.Vehicle speed is more than
1.5km/h.1. VSS open circuit, short
to ground or short to
voltage.
2. Poor connector
c o n n e c t i o n .
3. VSS malfunction.
4. Speed meter
m a l f u n c t i o n .
5. ECM malfunction.68 —
35 P0560 1 OFF System Voltage Too High System voltage is more than
20V.ECM uses 9V conditions as
substitute.System voltage is below 20V. 1. Charge system
m a l f u n c t i o n .
2. Battery jump start cable
misconnect.
3. ECM malfunction.3 /
39—
2 OFF System Voltage Too Low System voltage is below 7V. System voltage is more than
7V.1. Battery power feed
harness open circuit or
short to ground circuit.
2. ECM ground harness
open or poor connection.
3. Poor connector
c o n n e c t i o n .
4 . B a t t e r y m a l f u n c t i o n .
5. Charge system
m a l f u n c t i o n .
6. ECM malfunction.3 /
39— 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)

4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS 6E–125
43 P1335 A ON Engine Speed Output Circuit
MalfunctionThe PSG (pump control unit)
is recognized defective
engine speed signal form the
ECM.Fuel injection quantity is
reduced.Correct engine speed signal. 1. CKP sensor harness
open circuit, short to
ground or short to
voltage.
2. CKP sensor output
harness open circuit,
short to ground or short
t o v o l t a g e .
3. Poor connector
c o n n e c t i o n .
4. CKP sensor malfunction.
5. Pulse sensing gap
i n c o r r e c t .
6 . P u l s e r m a l f u n c t i o n .
7. Electrical interference.
8. Magnetic interference.
9. ECM malfunction.
10. PSG (pump control unit)
malfunction.9 0 /
9 1 /
9 8 /
101P0335(B)/











P0335(D)
45 P1345 A ON Camshaft Speed Malfunction The PSG (pump control unit)
is recognized incorrect
camshaft speed signal.No fail-safe function. Correct camshaft speed. 1. Pump camshaft speed
s e n s o r m a l f u n c t i o n .
2. Pulse sensing gap
i n c o r r e c t .
3 . P u l s e r m a l f u n c t i o n .
4. Electrical interference.
5. Magnetic interference.
6. ECM malfunction.
7. PSG (pump control unit)
malfunction.——
47 P1520 A ON Neutral Switch ON Error Neutral switch signal is
inputted "On" three times
consecutively under driving
conditions.No fail-safe function. Correct neutral switch signal
is inputted two times
consecutively under driving
conditions.1. Neutral switch circuit
short to voltage circuit.
2. Neutral switch
m a l f u n c t i o n .
3. ECM malfunction.87 —
B ON Neutral Switch OFF Error Neutral switch signal is
inputted "Off" three times
consecutively under driving
conditions.1. Neutral switch circuit
open, short to ground
c i r c u i t .
2. Poor connector
c o n n e c t i o n .
3. Neutral switch
m a l f u n c t i o n .
4. ECM malfunction.87 — —
55 P1605 C ON Seed and Key File Destroyed Seed or key file in EEPROM
is destroyed.No fail-safe function. No recovery. ECM malfunction.
——
D ON EEPROM Defect Write and read from the
EEPROM are failed during
initialization of the ECM.ECM uses default values
from the EPROM.Write and read from the
EEPROM are correct during
initialization of the ECM.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)

4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS 6E–141
Condition for setting the DTC and action taken when the DTC sets
Circuit description
The ECM monitors altitude from the barometric
pressure sensor. To apply specified vacuum pressure to
the turbocharger wastegate valve, ECM sends control
signal to the wastegate control solenoid depending on
altitude.
Then, apply vacuum pressure to the turbocharger
wastegate valve is monitored by the ECM form the
vacuum pressure sensor output signal. The ECM
controls wastegate control solenoid based on signal
from vacuum pressure sensor output.
The output voltage ex cessively high or low, DTC P0105
(Symptom Code 1) or P0105 (Symptom Code 2) will be
stored.
The supply voltage is out of range, DTC P0105
(Symptom Code 7) or P0105 (Symptom Code 9) will be
stored.
Diagnostic Aids
An intermittent may be caused by the following:
Poor connections.
Misrouted harness.
Rubbed through wire insulation.
Broken wire inside insulation.
Check for the following conditions:
Poor connection at ECM-Inspect harness connectors
for backed out terminals, improper mating, broken
locks, improperly formed or damaged terminals, and
poor terminal to wire connection.
Damaged harness-Inspect the wiring harness for
damage. If the harness appears to be OK, observe
the DTC P0105 display on the Tech 2 while moving
connectors and wiring harnesses. A change in the
display will indicate the location of the fault.
Flash
CodeCode Symptom
CodeMIL DTC Name DTC Setting Condition Fail-Safe (Back Up)
34 P0105 1 ON Vacuum Pressure Sensor
Circuit High InputVacuum sensor output
voltage is more than 4.4V.1. Fuel injection quantity is
r e d u c e d .
2. ECM use 615hpa
conditio ns for
turbo cha rge r wa ste gate
contro l. 2 ON Vacuum Pressure Sensor
Circuit Low InputVacuum sensor output
voltage is below 0.5V.
7 ON Vacuum Pressure Sensor
Volta ge Supply Circuit High
InputVacuum senso r po wer 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. 9 ON Vacuum Pressure Sensor
Volta ge Supply Circuit Lo w
InputVacuum senso r po wer supply
voltage is below 4.5V.

6E–168 4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS
DIAGNOSTIC TROUBLE CODE (DTC) P0180 (SYMPTOM CODE B)
(FLASH CODE 15) FUEL TEMPERATURE SENSOR CIRCUIT RANGE/
PERFORMANCE
Condition for setting the DTC and action taken when the DTC sets
Circuit Description
The fuel temperature sensor is assembled inside of the
pump control unit (PSG). The signal of fuel temperature
is sent via the CAN-bus from the PSG to ECM.
If the fuel temperature is ex cessively high or low
condition, DTC P0180 will be stored.
Diagnostic Aids
An intermittent may be caused by the following:
Poor connections.Misrouted harness.
Rubbed through wire insulation.
Broken wire inside the insulation.
Check for the following conditions:
Poor connection at ECM and PSG-Inspect harness
connectors for backed out terminals, improper
mating, broken locks, improperly formed or damaged
terminals, and poor terminal to wire connection.
Damaged harness-Inspect the wiring harness for
damage. If the harness appears to be OK, observe
the “Fuel Temperature” display on the Tech2 while
Flash
CodeCode Symptom
CodeMIL DTC Name DTC Setting Condition Fail-Safe (Back Up)
15 P0180 B ON Fuel Temperature Sensor Cir-
cuit Range/PerformanceFT sensor output is high tem-
pe ra ture (mo re tha n
150deg.C) or low temperature
(below -40deg.C).The ECM use 75de g.C condi-
tions as substitute.

4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS 6E–169
moving connectors and wiring harness related to the
sensor.
Diagnostic Trouble Code (DTC) P0180 (Sy mptom Code B) (Flash Code 15) Fuel
Temperature Sensor Circuit Range/Performance
Step Action Value(s) Yes No
1Was the “On-Board Diagnostic (OBD) System Check”
performed?
—Go to Step 2Go to On Board
Diagnostic
(OBD) System
Check
2 1. Connect the Tech 2.
2. Review and record the failure information.
3. Select “F0: Read DTC Infor As Stored By ECU” in
“F0: Diagnostic Trouble Codes”.
Is the DTC P0180 (Symptom Code B) stored as
“Present Failure”?—Go to Step 3Refer to
Diagnostic Aids
and Go to Step
3
3 1. Using the Tech 2, ignition “On” and engine “Off”.
2. Select “F1: Clear DTC Information” in “F0:
Diagnostic Trouble Codes” with the Tech 2 and
clear the DTC information.
3. Operate the vehicle and monitor the “F0: Read
DTC Infor As Stored By ECU” in the “F0:
Diagnostic Trouble Codes”.
Was the DTC P0180 (Symptom Code B) stored in this
ignition cycle?—Go to Step 4Refer to
Diagnostic Aids
4 Is the ECM programmed with the latest software
release?
If not, download the latest software to the ECM using
the “SPS (Service Programming System)”.
Was the problem solved?—Verify repair Go to Step 5
5 Substitute a known good ECM and recheck.
Was the problem solved?
IMPORTANT: The replacement ECM must be
programmed. Refer to section of the Service
Programming System (SPS) in this manual.
Following ECM programming, the immobilizer system
(if equipped) must be linked to the ECM. Refer to
section 11 “Immobilizer System-ECM replacement” for
the ECM/Immobilizer linking procedure. —Go to Step 6Go to Step 7
6 Replace the ECM.
Is the action complete?
IMPORTANT: The replacement ECM must be
programmed. Refer to section of the Service
Programming System (SPS) in this manual.
Following ECM programming, the immobilizer system
(if equipped) must be linked to the ECM. Refer to
section 11 “Immobilizer System-ECM replacement” for
the ECM/Immobilizer linking procedure.—Verify repair—
7 Replace the injection pump assembly.
Is the action complete?—Verify repair—

4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS 6E–179
Circuit Description
The ECM is calculates an injection quantity and an
injection timing using the various sensors (crankshaft
position sensor, camshaft position sensor, engine
coolant temperature sensor, etc.). The timing control
valve (TCV) operation performs an injection timing
decision.
The TCV performs as a variable throttle, using the rapid
opening and closing cycle of the valve needle in the
TCV.
The TCV is assembled in the injection pump. The signal
of desired injection timing and actual injection timing are
ex changed via the CAN-bus between the PSG and
ECM.
If the timer position is out of tolerance (deviation or
fluctuation), DTC P0216 will be stored.
Diagnostic Aids
An intermittent may be caused by the following:
Poor connections.
Misrouted harness.
Rubbed through wire insulation.
Broken wire inside the insulation.
Insufficient air bleeding of fuel line.
Low fuel quantity in the fuel tank.
Check for the following conditions:
Insufficient air bleeding of fuel line inside, clogged
fuel filter or pinched fuel pipe/hose may cause the
DTC store or improper engine performance.Air bleeding procedure:
1.Operate the priming pump until strong resistance is
felt.
2.Wait 1 minute, and operate the priming pump until
strong resistance is felt.
3.Wait 1 minute, and operate the priming pump until
strong resistance is felt.
4.Turn the ignition switch to the "ON" position. Wait
until the glow indicator lamp turns off.
5.Turn the ignition switch to the "START" position and
crank the engine until it starts.
6.If the engine does not start, repeat Step 3 - 5.
7.Allow the engine to idle for 3 minutes to bleed air
completely form the fuel system and check for fuel
leakage.
Poor connection at ECM and PSG-Inspect harness
connectors for backed out terminals, improper
mating, broken locks, improperly formed or damaged
terminals, and poor terminal to wire connection.
Damaged harness-Inspect the wiring harness for
damage. If the harness appears to be OK, observe
the "Actual Injection Start" display on the Tech2 while
moving connectors and wiring harness related to the
sensor.

6E–184 4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS
Condition for setting the DTC and action taken when the DTC sets
Circuit description
The ECM monitors altitude from the barometric
pressure sensor. To apply specified vacuum pressure to
the turbocharger wastegate valve, ECM sends control
signal to the wastegate control solenoid depending on
altitude.
Then, apply vacuum pressure to the turbocharger
wastegate valve is monitored by the ECM form the
vacuum pressure sensor output signal. The ECM
controls wastegate control solenoid based on signal
from vacuum pressure sensor output.
If the vacuum pressure sensor detected vacuum
pressure is excessively low or high due to faulty vacuum
line, vacuum pump or turbocharger wastegate valve,
DTC P0243 (Symptom Code 3), P0243 (Symptom Code
5) or P0243 (Symptom Code 6) will be stored.
If the wastegate control solenoid circuit is open or short
to ground circuit, DTC P0243 (Symptom Code 4) will be
stored.
If the wastegate control solenoid circuit is short to
voltage circuit, DTC P0243 (Symptom Code 8) will be
stored.
Diagnostic Aids
An intermittent may be caused by the following:
Poor connections.
Misrouted harness.
Rubbed through wire insulation.
Broken wire inside insulation.
Turbocharger wastegate valve sticking or broken.
Misrouted vacuum hose.
Faulty vacuum pump or regulating valve.
Check for the following conditions:
Poor connection at ECM-Inspect harness connectors
for backed out terminals, improper mating, broken
locks, improperly formed or damaged terminals, and
poor terminal to wire connection.
Damaged harness-Inspect the wiring harness for
damage. If the harness appears to be OK, observe
the DTC P0243 display on the Tech 2 while moving
connectors and wiring harnesses. A change in the
display will indicate the location of the fault.
Flash
CodeCode Symptom
CodeMIL DTC Name DTC Setting Condition Fail-Safe (Back Up)
64 P0243 3 ON Turbocharger Wastegate
So le no id "A" Ra nge/
Pe rfo rma nce1. 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. 1. Fuel injection quantity is
r e d u c e d .
2. EGR EVRV becomes 10%
co nditio n.
4 ON Turbocharger Wastegate
So le no id "A" Lo w 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 10%
c o n d i t i o n .
3. Wastegate control EVRV
be co mes 32% conditio n.
5 ON Turbocharger Wastegate
So le no id "A" Ra nge/
Pe rfo rma nce1. 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. 1. Fuel injection quantity is
r e d u c e d .
2. EGR EVRV becomes 10%
co nditio n.
6 ON Turbocharger Wastegate
So le no id "A" Malfunctio n1. Engine coolant
temperature is between -
50 deg. C and 150 deg.
C .
2. EGR contro l EVRV 0%
co nditio n.
8 ON Turbocharger Wastegate
So le no id "A" HighWastegate control EVRV
circuit short to voltage circuit.1. Fuel injection quantity is
r e d u c e d .
2. EGR EVRV becomes 10%
c o n d i t i o n .
3. Wastegate control EVRV
be co mes 32% conditio n.

4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS 6E–197
Condition for setting the DTC and action taken when the DTC sets
Circuit Description
The ECM is calculates an injection quantity and an
injection timing using the various sensors. And the PSG
controls the high pressure solenoid valve depending on
programmed pump map data.
The signal of desired injection quantity and actual injec-
tion quantify are ex changed via the CAN-bus between
the PSG and ECM.
If the relation of engine speed signal and doubled pump
camshaft speed signal ex cessively large, DTC P0251
(Symptom Code 7) will be stored.
If the CAN high or low circuit is defected, DTC P0251
(Symptom Code E) will be stored.
Diagnostic Aids
An intermittent may be caused by the following:
Poor connections.
Misrouted harness.
Rubbed through wire insulation.
Broken wire inside the insulation.
Check for the following conditions:
Poor connection at ECM and PSG-Inspect harness
connectors for backed out terminals, improper
mating, broken locks, improperly formed or damaged
terminals, and poor terminal to wire connection.
Damaged harness-Inspect the wiring harness for
damage. If the harness appears to be OK, observe
the “Injection Quantity” display on the Tech2 while
moving connectors and wiring harness related to the
sensor.
Diagnostic Trouble Code (DTC) P0251 (Symptom Code 6) (Flash Code 53)
Injection Pump Malfunction
Flash
CodeCode Symptom
CodeMIL DTC Name DTC Setting Condition Fail-Safe (Back Up)
53 P0251 6 ON Injection Pump Malfunction 1. No pump camshaft speed
se nsor erro r.
2. High pressure solenoid
v a lv e co ntro l pulse w idth
doe s no t ma tch with
desired fuel injection quan-
tity. 1. MAB (fuel cutoff solenoid
valve) is operated.
2. Desired injection quantity
becomes 0mg/strk.
7 ON Injection Pump Malfunction 1. No pump camshaft speed
se nsor erro r.
2. No CKP senso r e rror.
3. Difference of engine speed
and doubled pump cam-
shaft speed is more than
720rpm (4JA1-TC) or 690
rpm (4JH1-TC).
9 ON Injection Pump Malfunction No pump map programmed in
the PSG (pump co ntrol unit)
or PSG malfunction.
A ON Injection Pump Malfunction EEPROM or A/D converter
malfunctio n in the PSG (pump
control unit).Fuel inje ctio n qua ntity is
reduced.
B ON Injection Pump Malfunction PSG (pump control unit) rec-
ognized high pressure sole -
noid valve drive circuit error.No fa il-sa fe fun ctio n.
D ON Injection Pump Malfunction PSG (pump control unit) could
no t me asure the high pres-
sure solenoid valve drive volt-
age.
E ON Injection Pump Malfunction ECM could not accept PSG
(pump co ntrol unit) messa ge.1. MAB (fuel cutoff solenoid
valve) is operated.
2. Desired injection quantity
becomes 0mg/strk.
Step Action Value(s) Yes No
1Was the “On-Board Diagnostic (OBD) System Check”
performed?
—Go to Step 2Go to On Board
Diagnostic
(OBD) System
Check