Isuzu KB P190. Manual - part 436

ENGINE CONTROL SYSTEM (4JK1/4JJ1)   6E-127

10

Important: The FRP sensor may be damaged if
the sensor signal circuit is shorted to a voltage
source.

1.

Test the signal circuits between the ECM (pins
48 and 68 of E-90) and the FRP sensor (pin 2
of E-48) for a short to battery or ignition
voltage.

2.

Repair the circuit(s) as necessary.

Did you find and correct the condition?

—

Go to Step 15

Go to Step 14

11

1.

Inspect for an intermittent and for poor
connections at the harness connector of the
FRP sensor (pins 1 and 2 of E-48).

2.

Repair the connection(s) as necessary.

Did you find and correct the condition?

—

Go to Step 15

Go to Step 13

12

1.

Turn OFF the ignition.

2.

Disconnect the ECM harness connector.

3.

Inspect for an intermittent and for poor
connections at the harness connector of the
ECM (pins 48, 68 and 69 of E-90).

4.

Repair the connection(s) as necessary.

Did you find and correct the condition?

—

Go to Step 15

Go to Step 14

13

Replace the FRP sensor. Refer to FRP Sensor
Replacement.

Did you complete the replacement?

—

Go to Step 15

—

14

Important: Replacement ECM must be
programmed and learned.
Replace the ECM. Refer to ECM Replacement.

Did you complete the replacement?

—

Go to Step 15

—

15

1.

Reconnect all previously disconnected
harness connector(s).

2.

Clear the DTCs with a scan tool.

3.

Turn OFF the ignition for 30 seconds.

4.

Start the engine.

5.

Operate the vehicle within the Conditions for
Running the DTC. You may also operate the
vehicle within the conditions that you
observed from the Freeze Frame/ Failure
Records.

Did the DTC fail this ignition?

—

Go to Step 3

Go to Step 16

16

Observe the DTC Information with a scan tool.

Are there any DTCs that you have not diagnosed?

—

Go to DTC List

System OK

Step

Action

Value(s)

Yes

No

6E-128   ENGINE CONTROL SYSTEM (4JK1/4JJ1)

DTC P0201, P0202, P0203 or P0204 (Flash Code 271, 272, 273 or 274)

Circuit Description

The ECM calculates the optimum fuel injection ON time
using data sent from various engine sensors. The ECM
supplies a high voltage along with grounding the fuel
injector control circuit when it needs to energize the fuel
injector (turn it ON). If the fuel injector charge voltage
circuit or solenoid control circuit is open circuit, this
DTC will set. DTC P0201 - P0204 will set depending
upon which cylinder injector circuit failed.

Condition for Running the DTC

• DTCs P2146, P2147 and P2148 are not set. (DTC

P0201 or P0204)

• DTCs P2149, P2150 and P2151 are not set. (DTC

P0203 or P0204)

• The battery voltage is more than 9 volts.

• The ignition switch is ON.

• The engine is running.

• The engine speed is lower than 2000RPM.

Condition for Setting the DTC

• The ECM detects an open circuit on the fuel

injector solenoid circuits.

Action Taken When the DTC Sets

• The ECM illuminates the MIL when the diagnostic

runs and fails. Refer to DTC Type Definitions for
Action Taken When the DTC Sets - Type A.

• The ECM inhibits cruise control.

Condition for Clearing the DTC

• Refer to DTC Type Definitions for Condition for

Clearing the MIL/ DTC - Type A.

Diagnostic Aids

• If an intermittent condition is suspected, refer to

Intermittent Conditions in this section.

Notice:

• Each DTC agrees with engine cylinder order.

- P0201: Cylinder #1

- P0202: Cylinder #2

- P0203: Cylinder #3

- P0204: Cylinder #4

Schematic Reference: Engine Controls Schematics

Connector End View Reference: Engine Controls
Connector End Views or ECM Connector End Views

Circuit/ System Testing DTC P0201

Step

Action

Value(s)

Yes

No

1

Did you perform the Diagnostic System Check -
Engine Controls?

—

Go to Step 2

Go to Diagnostic 

System Check - 
Engine Controls

2

1.

Install a scan tool.

2.

Turn OFF the ignition for 30 seconds.

3.

Start the engine.

4.

Monitor the DTC Information with a scan tool.

Does the DTC fail this ignition?

—

Go to Step 3

Go to Diagnostic 

Aids

3

1.

Turn OFF the ignition.

2.

Disconnect the cylinder #1 fuel injector
harness connector.

3.

Inspect for an intermittent and for poor
connections at the harness connector (pins 1
and 2 of E-13).

4.

Repair the connection(s) as necessary.

Did you find and correct the condition?

—

Go to Step 11

Go to Step 4

4

Measure the resistance of cylinder #1 fuel injector
solenoid.

Is the resistance less the specified value?

2.0 

Ω

Go to Step 5

Go to Step 9

ENGINE CONTROL SYSTEM (4JK1/4JJ1)   6E-129

5

1.

Disconnect the cylinder #4 fuel injector
harness connector.

2.

Measure the resistance of the charge voltage
circuit between the cylinder #1 and #4 fuel
injector (pin 2 of E-13 and pin 2 of E-16).

Is the resistance less than the specified value?

1.0 

Ω

Go to Step 6

Go to Step 7

6

1.

Test the control circuit between the ECM (pin
33 of E-90) and the cylinder #1 fuel injector
(pin 1 of E-13) for an open circuit or high
resistance.

2.

Repair the circuit(s) as necessary.

Did you find and correct the condition?

—

Go to Step 11

Go to Step 8

7

1.

Test the charge voltage circuit between the
ECM (pin 52 of E-90) and the cylinder #1 fuel
injector (pin 2 of E-13) for an open circuit or
high resistance.

2.

Repair the circuit(s) as necessary.

Did you find and correct the condition?

—

Go to Step 11

Go to Step 8

8

1.

Turn OFF the ignition.

2.

Disconnect the ECM harness connector.

3.

Inspect for an intermittent and for poor
connections at the harness connector of the
ECM (pins 33 and 52 of E-90).

4.

Repair the connection(s) as necessary.

Did you find and correct the condition?

—

Go to Step 11

Go to Step 10

9

Important: Replacement fuel injector must be
programmed.
Replace the cylinder #1 fuel injector. Refer to Fuel
Injector Replacement/ Fuel Injector ID Code Data
Programming.

Did you complete the replacement?

—

Go to Step 11

—

10

Important: Replacement ECM must be
programmed and learned.
Replace the ECM. Refer to ECM Replacement.

Did you complete the replacement?

—

Go to Step 11

—

11

1.

Reconnect all previously disconnected
harness connector(s).

2.

Clear the DTCs with a scan tool.

3.

Turn OFF the ignition for 30 seconds.

4.

Start the engine.

5.

Operate the vehicle within the Conditions for
Running the DTC. You may also operate the
vehicle within the conditions that you
observed from the Freeze Frame/ Failure
Records.

Did the DTC fail this ignition?

—

Go to Step 3

Go to Step 12

12

Observe the DTC Information with a scan tool.

Are there any DTCs that you have not diagnosed?

—

Go to DTC List

System OK

Step

Action

Value(s)

Yes

No

6E-130   ENGINE CONTROL SYSTEM (4JK1/4JJ1)

Circuit/ System Testing DTC P0202

Step

Action

Value(s)

Yes

No

1

Did you perform the Diagnostic System Check -
Engine Controls?

—

Go to Step 2

Go to Diagnostic 

System Check - 
Engine Controls

2

1.

Install a scan tool.

2.

Turn OFF the ignition for 30 seconds.

3.

Start the engine.

4.

Monitor the DTC Information with a scan tool.

Does the DTC fail this ignition?

—

Go to Step 3

Go to Diagnostic 

Aids

3

1.

Turn OFF the ignition.

2.

Disconnect the cylinder #2 fuel injector
harness connector.

3.

Inspect for an intermittent and for poor
connections at the harness connector (pins 1
and 2 of E-14).

4.

Repair the connection(s) as necessary.

Did you find and correct the condition?

—

Go to Step 11

Go to Step 4

4

Measure the resistance of cylinder #2 fuel injector
solenoid.

Is the resistance less the specified value?

2.0 

Ω

Go to Step 5

Go to Step 9

5

1.

Disconnect the cylinder #3 fuel injector
harness connector.

2.

Measure the resistance of the charge voltage
circuit between the cylinder #2 and #3 fuel
injector (pin 2 of E-14 and pin 2 of E-15).

Is the resistance less than the specified value?

1.0 

Ω

Go to Step 6

Go to Step 7

6

1.

Test the control circuit between the ECM (pin
24 of E-90) and the cylinder #2 fuel injector
(pin 1 of E-14) for an open circuit or high
resistance.

2.

Repair the circuit(s) as necessary.

Did you find and correct the condition?

—

Go to Step 11

Go to Step 8

7

1.

Test the charge voltage circuit between the
ECM (pin 71 of E-90) and the cylinder #2 fuel
injector (pin 2 of E-14) for an open circuit or
high resistance.

2.

Repair the circuit(s) as necessary.

Did you find and correct the condition?

—

Go to Step 11

Go to Step 8

8

1.

Turn OFF the ignition.

2.

Disconnect the ECM harness connector.

3.

Inspect for an intermittent and for poor
connections at the harness connector of the
ECM (pins 24 and 71 of E-90).

4.

Repair the connection(s) as necessary.

Did you find and correct the condition?

—

Go to Step 11

Go to Step 10

9

Important: Replacement fuel injector must be
programmed.
Replace the cylinder #2 fuel injector. Refer to Fuel
Injector Replacement/ Fuel Injector ID Code Data
Programming.

Did you complete the replacement?

—

Go to Step 11

—