Isuzu KB P190. Manual - part 272

6E-54  Engine Control System (4JH1) 

DTC 

(Symptom 

Code) 

Flash 

Code 

MIL 

Status 

DTC Name on 

scan tool 

Condition for 

Running the DTC

Condition for 

Setting the DTC

Possible Cause 

P0243 

(8) 

64 ON 

Turbocharger 
Waste gate 
Solenoid Boost 
Solenoid Circuit 
High Voltage 

• The ignition switch 

is ON. 

• The ECM detects 

that the high 
voltage condition on 
the turbocharger 
solenoid valve 
control circuit for 
longer than 3 
seconds when the 
solenoid valve is 
commanded ON. 

 

• Turbocharger solenoid valve 

control circuit is short to battery 
or ignition voltage circuit. 

• Faulty turbocharger solenoid 

valve. 

• Faulty ECM. 
 

P0251 

(6) 

53 ON 

Injection 

Pump 

Fuel Metering 
Control 

• The fuel injection 

pump CMP sensor 
signal is generated.

• The CAN 

communication 
between the ECM 
and PCU is normal.

 

• The PCU detects 

that the fuel 
injection solenoid 
valve is operated 
when the desired 
fuel injection 
quantity is 
commanded 0 
mg/strk.  

 

• Faulty fuel injection pump. 

• Faulty PCU. 
 
 

P0251 

(7) 

53 ON 

Injection 

Pump 

Fuel Metering 
Control 

• The fuel injection 

pump CMP sensor 
signal is generated.

• The CKP sensor 

signal is generated.

• The engine speed 

is higher than 500 
RPM. 

 

• The PCU detects 

that the doubled 
fuel injection pump 
speed is lower than 
engine speed by 
690 RPM for longer 
than 0.2 seconds. 

 

• Faulty CKP sensor signal. 

• Faulty fuel injection pump CMP 

sensor signal.  

• Electrical interference. 

• Magnetic interference. 

• Faulty PCU. 
 

P0251 

(9) 

53 ON 

Injection 

Pump 

Fuel Metering 
Control 

• The ignition switch 

is ON. 

• The PCU detects 

internal fuel 
injection pump 
control maps are 
not programmed 
during self-test.  

 

• Faulty PCU. 
 
 

P0251 

(A) 

53 ON 

Injection 

Pump 

Fuel Metering 
Control 

• The ignition switch 

is ON. 

• The PCU detects 

internal EEPROM 
or A/D converter is 
failed during self-
test.  

 

• Faulty PCU. 
 
 

P0251 

(B) 

53 ON 

Injection 

Pump 

Fuel Metering 
Control 

• The ignition switch 

is ON. 

• The PCU detects 

that the fuel 
injection solenoid 
valve drive circuit is 
failed during self-
test.  

 

• Faulty fuel injection pump. 

• Faulty PCU. 
 
 

P0251 

(D) 

53 ON 

Injection 

Pump 

Fuel Metering 
Control 

• The ignition switch 

is ON. 

• The PCU detects 

that the fuel 
injection solenoid 
valve drive circuit 
voltage level is 
abnormal during 
self-test.  

 

• Faulty fuel injection pump. 

• Faulty PCU. 
 
 

Engine Control System (4JH1)  6E-55 

DTC 

(Symptom 

Code) 

Flash 

Code 

MIL 

Status 

DTC Name on 

scan tool 

Condition for 

Running the DTC

Condition for 

Setting the DTC

Possible Cause 

P0251 

(E) 

53 ON 

Injection 

Pump 

Fuel Metering 
Control 

• The ignition switch 

is ON. 

• The ECM detects 

communication 
message from the 
PCU is not received 
for longer than 1 
second. 

 

• CAN high circuit is open circuit, 

high resistance, short to ground, 
short to battery or ignition 
voltage. 

• CAN low circuit is open circuit, 

high resistance, short to ground, 
short to battery or ignition 
voltage. 

• Electrical interference. 

• Magnetic interference. 

• Faulty PCU. 

• Faulty ECM.  
 

P0335 

(B) 

43 ON 

 

Crankshaft 
Position (CKP) 
Sensor Circuit  

• The ignition switch 

is ON. 

• The engine speed 

is higher than 665 
RPM. 

 

• The ECM detects 

extra or missing 
CKP sensor signals 
while engine is 
running.  

• Sensor signal circuit is open 

circuit, high resistance, short to 
ground, short to battery or short 
to ignition voltage. 

• Sensor low reference circuit is 

open circuit, high resistance, 
short to ground, short to battery 
or short to ignition voltage. 

• Sensor shield ground is open 

circuit, high resistance, short to 
ground, short to battery or short 
to ignition voltage. 

• Faulty CKP sensor. 

• Faulty ECM. 

• Electrical interference. 

• Magnetic interference. 

• Faulty sensor installation.  

• Faulty flywheel circumference.  
 

P0335 

(D) 

43 ON 

 

Crankshaft 
Position (CKP) 
Sensor Circuit  

• DTC P0335 

(Symptom Code B) 
is not set. 

• The ignition switch 

is ON. 

• The fuel injection 

pump CMP sensor 
signal is generated.

• The CAN 

communication 
between the ECM 
and PCU is normal.

 

• The ECM detects 

that the CKP sensor 
signals are not 
generated when 
doubled fuel 
injection pump 
rotation speed is 
higher than 50 
RPM. 

 

• Sensor signal circuit is open 

circuit, high resistance, short to 
ground, short to battery or short 
to ignition voltage. 

• Sensor low reference circuit is 

open circuit, high resistance, 
short to ground, short to battery 
or short to ignition voltage. 

• Sensor shield ground is open 

circuit, high resistance, short to 
ground, short to battery or short 
to ignition voltage. 

• Faulty CKP sensor. 

• Faulty ECM. 

• Electrical interference. 

• Magnetic interference. 

• Faulty sensor installation.  

• Faulty flywheel circumference.  
 

P0335 

(E) 

43 ON 

Crankshaft 
Position (CKP) 
Sensor Circuit  

• Ignition switch is 

ON. 

 

• The ECM detects 

that the engine 
speed is higher 
than 5700 RPM for 
0.2 seconds.  

• Engine overrun. 

• Faulty CKP sensor. 

• Faulty ECM. 

• Electrical interference. 

• Magnetic interference. 

• Faulty flywheel circumference.  
 

6E-56  Engine Control System (4JH1) 

DTC 

(Symptom 

Code) 

Flash 

Code 

MIL 

Status 

DTC Name on 

scan tool 

Condition for 

Running the DTC

Condition for 

Setting the DTC

Possible Cause 

P0380 

(4) 

66 

ON 

Glow Plug Relay 
Control Circuit Low 
Voltage 

• The ignition switch 

is ON. 

• The ECM detects 

that the low voltage 
condition on the 
glow relay control 
circuit for longer 
than 3 seconds 
when the relay is 
commanded OFF. 

 

• ECM (10A) fuse (EB1) open. 

• Glow relay ignition voltage feed 

circuit on coil side is open circuit 
or high resistance. 

• Glow relay control circuit is open 

circuit, high resistance or short 
to ground. 

• Glow relay is poor installation. 

• Faulty glow relay. 

• Faulty ECM.  
 

P0380 

(8) 

66 ON 

 

Glow Plug Relay 
Control Circuit 
High Voltage 

• The ignition switch 

is ON. 

• The ECM detect 

that the high 
voltage condition on 
the glow relay 
control circuit for 
longer than 1 
second when the 
relay is commanded 
ON.  

 

• Glow relay control circuit is short 

to battery or ignition voltage 
circuit. 

• Faulty glow relay. 

• Faulty ECM. 
 

P0381 

(4) 

67 ON 

Glow 

Plug 

Indicator Circuit 
Low Voltage 

• The ignition switch 

is ON. 

 

• The ECM detects 

that the low voltage 
condition on the 
glow indicator lamp 
control circuit for 
longer than 3 
seconds when the 
indicator lamp is 
commanded OFF. 

 

• Meter (15A) fuse (C-14) open. 

• Glow indicator lamp ignition 

voltage feed circuit is open 
circuit or high resistance. 

• Glow indicator lamp control 

circuit is open circuit, high 
resistance or short to ground. 

• Poor harness connector 

connection. 

• Glow indicator lamp bulb burned 

out. 

• Faulty instrument panel cluster 

(meter assembly). 

• Faulty ECM.  
 

P0381 

(8) 

67 ON 

Glow 

Plug 

Indicator Circuit 
High Voltage 

• The ignition switch 

is ON. 

• The ECM detects 

that the high 
voltage condition on 
the glow indicator 
lamp control circuit 
for longer than 1 
second when the 
indicator lamp is 
commanded ON.  

 

• Glow indicator lamp control 

circuit is short to battery or 
ignition voltage circuit. 

• Faulty instrument panel cluster 

(meter assembly). 

• Faulty ECM. 
 

P0400 

(3) 

32 ON 

Exhaust 

Gas 

Recirculation 
(EGR) System 
Performance 

• The ignition switch 

is ON. 

• The engine is 

running.  

• The BARO is 

between 850 hPa 
and 1100 hPa. 

• The IAT is between 

15°C (59°F) and 
100°C (212°F). 

• The ECT is 

between 35°C 
(95°F) and 100°C 
(211°F). 

 

• The ECM detects 

that the MAF 
amount is 150 
mg/strk lower than 
the desired MAF for 
60 seconds.  

 

• MAF sensor circuits are high 

resistance. 

• MAF sensor signal circuit is short 

to IAT sensor signal circuit. 

• Intake air leakage. 

• Intake duct disconnected. 

• Intake system is obstructed. 

• Faulty turbocharger.  

• Faulty exhaust system. 

• Faulty EGR valve vacuum 

control system. 

• Faulty EGR valve. 

• Faulty EGR solenoid valve. 

• Faulty EGR solenoid valve 

vacuum hose routing. 

• Faulty MAF sensor. 
 

Engine Control System (4JH1)  6E-57 

DTC 

(Symptom 

Code) 

Flash 

Code 

MIL 

Status 

DTC Name on 

scan tool 

Condition for 

Running the DTC

Condition for 

Setting the DTC

Possible Cause 

P0400 

(4) 

32 ON 

Exhaust 

Gas 

Recirculation 
(EGR) Solenoid 
Circuit Low 
Voltage 

• The ignition switch 

is ON. 

 

• The ECM detects 

that the low voltage 
condition on the 
EGR solenoid valve 
control circuit for 
longer than 3 
seconds when the 
solenoid valve is 
commanded OFF. 

 

• ECM (10A) fuse (EB1) open. 

• EGR solenoid valve ignition 

voltage feed circuit is open 
circuit or high resistance. 

• EGR solenoid valve control 

circuit is open circuit, high 
resistance or short to ground. 

• Poor harness connector 

connection. 

• Faulty EGR solenoid valve. 

• Faulty ECM.  
 

P0400 

(5) 

32 ON 

Exhaust 

Gas 

Recirculation 
(EGR) System 
Performance 

• The ignition switch 

is ON. 

• The engine is 

running.  

• The BARO is 

between 850 hPa 
and 1100 hPa. 

• The IAT is between 

15°C (59°F) and 
100°C (212°F). 

• The ECT is 

between 35°C 
(95°F) and 100°C 
(211°F). 

 

• The ECM detects 

that the MAF 
amount is 150 
mg/strk higher than 
the desired MAF for 
60 seconds. 

 

• MAF sensor low reference circuit 

is high resistance. 

• Faulty EGR valve vacuum 

control system. 

• Faulty EGR valve. 

• Faulty vacuum pump 

• Faulty EGR solenoid valve. 

• Faulty EGR solenoid valve 

vacuum hose routing. 

• Faulty MAF sensor. 

• Faulty ECM. 
 

P0400 

(8) 

32 ON 

Exhaust 

Gas 

Recirculation 
(EGR) Solenoid 
Circuit High 
Voltage 
 

• The ignition switch 

is ON. 

 

• The ECM detects 

that the high 
voltage condition on 
the EGR solenoid 
valve control circuit 
for longer than 3 
seconds when the 
solenoid valve is 
commanded ON.  

 

• EGR solenoid valve control 

circuit is short to battery or 
ignition voltage circuit. 

• Faulty EGR solenoid valve. 

• Faulty ECM. 
 

P0500 

(1) 

24 ON 

Vehicle 

Speed 

Sensor (VSS) 
Circuit 
 

• The ignition switch 

is ON. 

• The ECM detects 

that the vehicle 
speed is higher 
than 200 km/h (125 
MPH) for 5 
seconds. 

 

• Vehicle speed too high. 

• Electrical interference. 

• Magnetic interference. 

• Faulty A/T VSS. (2WD with A/T)

• Faulty VSS. (Except 2WD with 

A/T) 

• Faulty ECM.  
 

P0500 

(A) 

24 ON 

Vehicle 

Speed 

Sensor (VSS) 
Circuit 
 

• The ignition switch 

is ON. 

• The ECM detects 

that the vehicle 
speed sensor signal 
frequency is too 
high for 0.6 
seconds. 

• Electrical interference. 

• Magnetic interference. 

• Faulty A/T VSS. (2WD with A/T)

• Faulty VSS. (Except 2WD with 

A/T) 

• Faulty ECM.