Isuzu KB P190. Manual - part 474

ENGINE CONTROL SYSTEM (4JK1/4JJ1) 6E-279

Turn OFF the ignition.

Disconnect the APP sensor harness
connector.

Inspect for an intermittent, for poor
connections and corrosion at the harness
connector of the APP sensor (pins 3, 8 and 9
of C-40).

Disconnect the ECM harness connector.

Inspect for an intermittent, for poor
connections and corrosion at the harness
connector of the ECM (pins 9, 10 and 25 of C-
58).

Repair the connection(s) as necessary.

Did you find and correct the condition?

—

Go to Step 12

Go to Step 8

Test the APP sensor 1 and sensor 2 signal
circuit between the ECM (pins 10 and 12 of C-
58) and the APP sensor (pins 5 and 9 of C-40)
for a short circuit each other.

Repair the circuit(s) as necessary.

Did you find and correct the condition?

—

Go to Step 12

Go to Step 9

Replace the APP sensor. Refer to APP Sensor
Replacement.

Did you complete the replacement?

—

Go to Step 10

—

Reconnect all previously disconnected
harness connector(s).

Clear the DTCs with a scan tool.

Turn OFF the ignition for 30 seconds.

Start the engine.

Fully depress and release the accelerator
pedal while observing the DTC Information
with a scan tool.

Does the DTC fail this ignition?

—

Go to Step 11

Go to Step 13

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

Did you complete the replacement?

—

Go to Step 12

—

Reconnect all previously disconnected
harness connector(s).

Clear the DTCs with a scan tool.

Turn OFF the ignition for 30 seconds.

Start the engine.

Fully depress and release the accelerator
pedal while observing the DTC Information
with a scan tool.

Did the DTC fail this ignition?

—

Go to Step 2

Go to Step 13

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

6E-280 ENGINE CONTROL SYSTEM (4JK1/4JJ1)

Circuit/ System Testing DTC P2140

Step

Action

Value(s)

Yes

Did you perform the Diagnostic System Check -
Engine Controls?

—

Go to Step 2

Go to Diagnostic

System Check -
Engine Controls

Install a scan tool.

Turn OFF the ignition for 30 seconds.

Start the engine.

Monitor the DTC Information with a scan tool.

Is DTC P0642, P0643, P0652, P0653, P0698,
P0699, P2122 or P2123 also set?

—

Go to Applicable

DTC

Go to Step 3

Fully depress and release the accelerator pedal
while observing the DTC Information with a scan
tool.

Does the DTC fail this ignition?

—

Go to Step 4

Go to Diagnostic

Aids

Is DTC P2138 also set?

—

Go to DTC P2138

Go to Step 5

Is DTC P2139 also set?

—

Go to Step 6

Go to Step 7

Test each accelerator pedal position (APP)
sensor 3 circuits between the ECM (pins 7, 8
and 23 of C-58) and the APP sensor (pins 1, 6
and 7 of C-40) for high resistance.

Repair the circuit(s) as necessary.

Did you find and correct the condition?

—

Go to Step 14

Go to Step 7

Test each APP sensor 1 circuits between the
ECM (pins 11, 12 and 27 of C-58) and the
APP sensor (pins 4, 5 and 10 of C-40) for high
resistance.

Repair the circuit(s) as necessary.

Did you find and correct the condition?

—

Go to Step 14

Go to Step 8

Turn OFF the ignition.

Disconnect the APP sensor harness
connector.

Inspect for an intermittent, for poor
connections and corrosion at the harness
connector of the APP sensor (pins 1, 4, 5, 6, 7
and 10 of C-40).

Disconnect the ECM harness connector.

Inspect for an intermittent, for poor
connections and corrosion at the harness
connector of the ECM (pins 7, 8, 11, 12, 23
and 27 of C-40).

Repair the connection(s) as necessary.

Did you find and correct the condition?

—

Go to Step 14

Go to Step 9

Test the APP sensor 1 and sensor 2 signal
circuit between the ECM (pins 10 and 12 of C-
58) and the APP sensor (pins 5 and 9 of C-40)
for a short circuit each other.

Repair the circuit(s) as necessary.

Did you find and correct the condition?

—

Go to Step 14

Go to Step 10

ENGINE CONTROL SYSTEM (4JK1/4JJ1) 6E-281

Test the APP sensor 1 and sensor 3 signal
circuit between the ECM (pins 8 and 12 of C-
58) and the APP sensor (pins 5 and 6 of C-40)
for a short circuit each other.

Repair the circuit(s) as necessary.

Did you find and correct the condition?

—

Go to Step 14

Go to Step 11

Replace the APP sensor. Refer to APP Sensor
Replacement.

Did you complete the replacement?

—

Go to Step 12

—

Reconnect all previously disconnected
harness connector(s).

Clear the DTCs with a scan tool.

Turn OFF the ignition for 30 seconds.

Start the engine.

Fully depress and release the accelerator
pedal while observing the DTC Information
with a scan tool.

Does the DTC fail this ignition?

—

Go to Step 13

Go to Step 15

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

Did you complete the replacement?

—

Go to Step 14

—

Reconnect all previously disconnected
harness connector(s).

Clear the DTCs with a scan tool.

Turn OFF the ignition for 30 seconds.

Start the engine.

Fully depress and release the accelerator
pedal while observing the DTC Information
with a scan tool.

Did the DTC fail this ignition?

—

Go to Step 2

Go to Step 15

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

6E-282 ENGINE CONTROL SYSTEM (4JK1/4JJ1)

DTC P2146, P2147 or P2148 (Flash Code 158)

Circuit Description

The ECM calculates the optimum fuel injection ON time
using data sent from various engine sensors. The
common 1 fuel injector charge voltage circuit is a high-
voltage supply which drives fuel injectors for cylinder #1
and #4 in conjunction with the ECM grounding the fuel
injector solenoid control circuit. If the common 1 fuel
injector charge voltage circuit is shorted to cylinder #1
or #4 fuel injector solenoid control circuit, shorted to
ground or shorted voltage circuit DTC P2146, P2147 or
P2148 will set. If the cylinder #1 and #4 fuel injector
solenoid control circuit is shorted each other, shorted to
ground or shorted voltage circuit DTC P2146, P2147 or
P2148 will also set.

Condition for Running the DTC

• DTCs P0201, P0204, P2147 and P2148 are not

set. (DTC P2146)

• The battery voltage is more than 9 volts.

• The ignition switch is ON.

• The engine is running.

Condition for Setting the DTC

• The ECM detects that the common 1 fuel injector

charge voltage circuit is shored to cylinder #1 or #4
fuel injector solenoid control circuit, or cylinder #1
and #4 fuel injector solenoid control circuit is
shorted each other. (DTC P2146)

• The ECM detects that the common 1 fuel injector

charge voltage circuit, cylinder #1 or #4 fuel
injector solenoid control circuit is shorted to
ground. (DTC P2147)

• The ECM detects that the common 1 fuel injector

charge voltage circuit, cylinder #1 or #4 fuel
injector solenoid control circuit is shorted to
voltage circuit. (DTC P2148)

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 limits fuel injection quantity.

• 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.

Schematic Reference: Engine Controls Schematics

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

Circuit/ System Testing DTC P2146

Step

Action

Value(s)

Yes

Did you perform the Diagnostic System Check -
Engine Controls?

—

Go to Step 2

Go to Diagnostic

System Check -
Engine Controls

Install a scan tool.

Turn OFF the ignition for 30 seconds.

Start the engine.

Accelerate the engine and keep the
accelerator pedal at any position.

Monitor the DTC Information with a scan tool.

Does the DTC fail this ignition?

—

Go to Step 3

Go to Diagnostic

Aids

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