Isuzu D-Max / Isuzu Rodeo (TFR/TFS). Service manual - part 26

4JA1-TC/4JH1-TC ENGINE DRIVEABILITY AND EMISSIONS

6E–99

46

P0645

4

ON

A/C Compressor Relay Circuit 
Voltage Low

A/C compressor relay circuit 
open or short to ground circuit.

No fail-safe function.

A/C compressor relay circuit is cor-
rect condition.

1. A/C compressor relay circuit 
open or short to ground circuit. 
2. Poor connector connection. 
3. A/C compressor relay malfunc-
tion. 
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 Malfunction

1. Throttle position is more 
than 0%. 
2. Engine speed is more than 
693rpm (4JA1-TC) or 665rpm 
(4JH1-TC). 
3. Vehicle speed is more than 
0km/h. 
4. Brake switch 1 signal and 
brake switch 2 signal are dif-
ferently 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 input-
ted to the ECM.

1. Brake switch 1 circuit open, 
short to ground or short to volt-
age circuit. 
2. Poor connector connection. 
3. Brake switch 1 malfunction. 
4. ECM malfunction.

30

-

B

ON

Brake Switch Malfunction

1. Throttle position is more 
than 0%. 
2. Engine speed is more than 
693rpm (4JA1-TC) or 665rpm 
(4JH1-TC). 
3. Vehicle speed is more than 
0km/h. 
4. Brake switch 1 signal and 
brake switch 2 signal are dif-
ferently inputted to the ECM.

1. Brake switch 2 circuit open or 
short to ground circuit. 
2. Poor connector connection. 
3. Brake switch 2 malfunction. 
4. ECM malfunction.

65

-

57

P0704

6

ON

Clutch Switch Input Circuit Mal-
function

Clutch 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 volt-
age circuit. 
2. Poor connector connection. 
3. Clutch switch malfunction. 
4. ECM malfunction.

31

-

-

86

P1105

1

ON

Barometric Pressure Sensor Cir-
cuit High Input

Barometric 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 Cir-
cuit Low Input

Barometric pressure sensor 
output voltage is below 1.5V.

Barometric pressure sensor output 
voltage is more than 1.5V.

ECM malfunction.

-

-

Flash 

Code

Code

Symptom 

Code

MIL

DTC Name

DTC Setting Condition

Fail-Safe (Back Up)

Recovery Condition

Related Failure Parts

Related 

ECM Pin 

No.

Related 

Multiple 

DTC

4JA1

-TC       

(MT)

4JH1

-TC 

(MT)

4JH1

-TC 

(AT)

6E–100

4JA1-TC/4JH1-TC ENGINE DRIVEABILITY AND EMISSIONS

21

P1120

1

ON

Pedal/Throttle Position Sensor 
Circuit High Input

Throttle position sensor out-
put voltage is more than 4.5V.

ECM increases idle speed up 
to 1400rpm.

Throttle position sensor output volt-
age is below 4.5V.

1. Sensor power supply circuit 
short to voltage circuit. 
2. Sensor signal circuit short to 
voltage circuit. 
3. Sensor ground circuit open or 
short to voltage circuit. 
4. Poor connector connection. 
5. TPS malfunction. 
6. ECM malfunction.

38/ 49/ 57

-

7

ON

Pedal/Throttle Position Sensor 
Voltage Supply Circuit High Input

Throttle position sensor power 
supply voltage is more than 
5.2V.

Throttle position sensor power sup-
ply voltage is below 5.2V.

1. Sensor power supply circuit 
short to battery voltage circuit. 
2. TPS malfunction. 
3. ECM malfunction.

57

-

9

ON

Pedal/Throttle Position Sensor 
Voltage Supply Circuit Low Input

Throttle position sensor power 
supply voltage is below 4.6V.

Throttle position sensor power sup-
ply voltage is more than 4.6V.

1. Sensor power supply circuit 
short to ground circuit. 
2. TPS malfunction. 
3. ECM malfunction.

57

-

D

ON

Pedal/Throttle Position Sensor 
Brake Switch Error

1. Engine speed is more than 
1700rpm. 
2. Throttle position sensor is 
more than 8.7%. 
3. When brake pedal is 
depressed during accelerator 
pedal is depressing. 

Throttle position is more than 20% 
or brake pedal is released (switch is 
inactive). 

1. Throttle sticking. 
2. TPS incorrect adjusting. 
3. TPS malfunction. 
4. Brake switch malfunction. 
5. ECM malfunction.

30/ 38/ 65

-

E

ON

Pedal/Throttle Position Sensor 
Idle Position Switch Error

1. When idle switch is turned 
off, throttle position sensor 
was below 0.35%. 
or 
2. When idle switch is tuned 
on, throttle position sensor 
was more than 7.8%.

1. When throttle position sensor is 
100%, idle switch turns off. 
2. When throttle position sensor is 
0%, idle switch turns on.

1. TPS malfunction. 
2. Idle switch malfunction. 
3. ECM malfunction.

38/ 69

-

22

P1173

3

OFF

Fuel Reduction Caused By High 
Coolant Temperature

Excessive high engine cool-
ant temperature is detected.

No fail-safe function.

Engine coolant temperature is nor-
mal range.

1. Engine overheat. 
2. ECT sensor malfunction. 
3. ECM malfunction.

89

-

7

OFF

Fuel Reduction Caused By High 
Fuel Temperature

Fuel temperature is more than 
100°C.

PSG (pump control unit) con-
trols fuel injection quantity 
based on engine speed and 
fuel temperature.

Fuel temperature is below 100°C.

1. ECM malfunction. 
2. PSG (pump control unit) mal-
function.

-

-

A

OFF

Fuel Reduction Caused By Low 
Fuel Temperature

Excessive low fuel tempera-
ture is detected.

No fail-safe function.

Fuel temperature is normal range.

1. ECM malfunction. 
2. PSG (pump control unit) mal-
function.

-

-

Flash 

Code

Code

Symptom 

Code

MIL

DTC Name

DTC Setting Condition

Fail-Safe (Back Up)

Recovery Condition

Related Failure Parts

Related 

ECM Pin 

No.

Related 

Multiple 

DTC

4JA1

-TC       

(MT)

4JH1

-TC 

(MT)

4JH1

-TC 

(AT)

4JA1-TC/4JH1-TC ENGINE DRIVEABILITY AND EMISSIONS

6E–101

43

P1335

A

ON

Engine Speed Output Circuit Mal-
function

The 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 cir-
cuit, short to ground or short to 
voltage. 
2. CKP sensor output harness 
open circuit, short to ground or 
short to voltage. 
3. Poor connector connection. 
4. CKP sensor malfunction. 
5. Pulse sensing gap incorrect. 
6. Pulser malfunction. 
7. Electrical interference. 
8. Magnetic interference. 
9. ECM malfunction. 
10. PSG (pump control unit) mal-
function.

90/91/98/

101

P0335(B)/ 

P0335(D)

45

P1345

A

ON

Camshaft Speed Malfunction

The PSG (pump control unit) 
is recognized incorrect cam-
shaft speed signal.

No fail-safe function.

Correct camshaft speed.

1. Pump camshaft speed sensor 
malfunction. 
2. Pulse sensing gap incorrect. 
3. Pulser malfunction. 
4. Electrical interference. 
5. Magnetic interference. 
5. ECM malfunction. 
6. PSG (pump control unit) mal-
function.

-

-

47

P1520

A

ON

Neutral Switch ON Error

Neutral switch signal is input-
ted “On” three times consecu-
tively 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 malfunction. 
3. ECM malfunction.

87

-

-

-

B

ON

Neutral Switch OFF Error

Neutral switch signal is input-
ted “Off” three times consecu-
tively under driving conditions.

1. Neutral switch circuit open, 
short to ground circuit. 
2. Poor connector connection. 
3. Neutral switch malfunction. 
4. ECM malfunction.

87

-

-

-

71

P1576

4

ON

Exhaust Throttle VSV 1 Circuit 
Voltage Low

Exhaust throttle VSV 1 circuit 
open or short to ground circuit.

No fail-safe function.

Exhaust throttle VSV 1 circuit is cor-
rect condition.

1. Exhaust throttle VSV 1 circuit 
open or short to ground circuit. 
2. Poor connector connection. 
3. Exhaust throttle VSV 1 mal-
function. 
4. ECM malfunction.

40

-

-

-

8

ON

Exhaust Throttle VSV 1 Circuit 
Voltage High

Exhaust throttle VSV 1 circuit 
short to voltage circuit.

ECM malfunction.

-

-

-

-

71

P1577

4

ON

Exhaust Throttle VSV 2 Circuit 
Voltage Low

Exhaust throttle VSV 2 circuit 
open or short to ground circuit.

No fail-safe function.

Exhaust throttle VSV 2 circuit is cor-
rect condition.

1. Exhaust throttle VSV 2 circuit 
open or short to ground circuit. 
2. Poor connector connection. 
3. Exhaust throttle VSV 2 mal-
function. 
4. ECM malfunction.

61

-

-

-

8

ON

Exhaust Throttle VSV 2 Circuit 
Voltage High

Exhaust throttle VSV 2 circuit 
short to voltage circuit.

ECM malfunction.

-

-

-

-

Flash 

Code

Code

Symptom 

Code

MIL

DTC Name

DTC Setting Condition

Fail-Safe (Back Up)

Recovery Condition

Related Failure Parts

Related 

ECM Pin 

No.

Related 

Multiple 

DTC

4JA1

-TC       

(MT)

4JH1

-TC 

(MT)

4JH1

-TC 

(AT)

6E–102

4JA1-TC/4JH1-TC ENGINE DRIVEABILITY AND EMISSIONS

55

P1605

D

ON

EEPROM Defect

Write and read from the 
EEPROM are failed during ini-
tialization 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.

-

-

E

ON

EEPROM Defect 

EEPROM checksum does not 
match with the read check 
sum during initialization of the 
ECM.

EEPROM checksum match with the 
read check sum during initialization 
of the ECM.

ECM malfunction.

-

-

56

P1610

A

-

Security Key and Security Code 
not Programmed

Immobiliser functions are not 
programmed in the ECM.

1. Engine does not start. 
2. Check engine lamp flash. 

No recovery.

ECM malfunction.

-

B****

56

P1611

A

-

Wrong Security Code Entered

Received security code is not 
correct.

1. Engine does not start. 
2. Check engine lamp flash. 

No recovery.

1. ECM malfunction. 
2. Immobiliser control unit mal-
function. 
3. Transponder key malfunction.

-

B****

56

P1612

A

-

Immobiliser No or Wrong Signal

Received challenge signal is 
not correct or not received.

1. Engine does not start. 
2. Check engine lamp flash. 

No recovery.

1. ECM and immobiliser control 
unit communication circuit open 
circuit, short to ground circuit or 
short to voltage circuit. 
2. ECM malfunction. 
3. Immobiliser control unit mal-
function. 
4. Transponder key malfunction.

27/35

B****

56

P1613

A

-

Immobiliser No or Wrong Signal

Received response signal is 
not correct or not received.

1. Engine does not start. 
2. Check engine lamp flash. 

No recovery.

1. ECM and immobiliser control 
unit communication circuit open 
circuit, short to ground circuit or 
short to voltage circuit. 
2. ECM malfunction. 
3. Immobiliser control unit mal-
function. 
4. Transponder key malfunction.

27/35

B****

56

P1614

A

-

Wrong Transponder Key

Received response signal is 
not correct from the transpon-
der key.

1. Engine does not start. 
2. Check engine lamp flash. 

No recovery.

1. ECM malfunction. 
2. Immobiliser control unit mal-
function. 
3. Transponder key malfunction.

-

B****

76

P1625

A

OFF

ECM Main Relay Switched Off 
Too Early

When ignition switch was 
turned off, timing of the ECM 
main relay turning off is too 
early.

No fail-safe function.

No recovery.

ECM malfunction.

3/58

-

B

OFF

ECM Main Relay Switched Off 
Too Late

When ignition switch was 
turned off, timing of the ECM 
main relay turning off is too 
late or does not off.

No recovery.

1. ECM main relay malfunction. 
2. ECM malfunction.

3/58

-

51

P1630

A

ON

Fuel Injection Quantity Circuit 
Malfunction

The PSG (pump control unit) 
detects high pressure solenoid 
valve control circuit malfunc-
tion due to high current.

Fuel injection quantity is 
reduced.

The PSG (pump control unit) 
detects correct high pressure sole-
noid valve control circuit.

PSG (pump control unit) malfunc-
tion.

-

-

B

ON

Fuel Injection Quantity Circuit 
Malfunction

The PSG (pump control unit) 
detects high pressure solenoid 
valve control circuit malfunc-
tion due to continuous current.

1. MAB (fuel cutoff solenoid 
valve) is operated. 
2. Desired injection quantity 
becomes 0mg/strk.

No recovery.

PSG (pump control unit) malfunc-
tion.

-

-

Flash 

Code

Code

Symptom 

Code

MIL

DTC Name

DTC Setting Condition

Fail-Safe (Back Up)

Recovery Condition

Related Failure Parts

Related 

ECM Pin 

No.

Related 

Multiple 

DTC

4JA1

-TC       

(MT)

4JH1

-TC 

(MT)

4JH1

-TC 

(AT)