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Isuzu KB P190. Manual - part 478

ENGINE CONTROL SYSTEM (4JK1/4JJ1) 6E-295

Circuit/ System Testing DTC P2229

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

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.

Observe the Barometric Pressure (BARO)
Sensor parameter with a scan tool.

Is the BARO Sensor parameter more than the
specified value?

4.3 volts

Go to Step 3

Go to Diagnostic

Aids

Monitor the DTC Information with a scan tool.

Is DTC P0653 also set?

—

Go to Step 4

Go to Step 5

Turn OFF the ignition.

Disconnect the BARO sensor harness
connector.

Turn ON the ignition, with the engine OFF.

Is the BARO Sensor parameter less than the
specified value?

0.1 volts

Go to DTC P0653

Go to Step 7

Turn OFF the ignition.

Disconnect the BARO sensor harness
connector.

Turn ON the ignition, with the engine OFF.

Is the BARO Sensor parameter less than the
specified value?

0.1 volts

Go to Step 6

Go to Step 7

Connect a test lamp between the low reference
circuit (pin 1 of E-40) and battery voltage.

Does the test lamp illuminate?

—

Go to Step 9

Go to Step 8

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

Test the signal circuit between the ECM (pin
18 of E-90) and the BARO sensor (pin 2 of E-
40) for the following conditions:

• A short to battery or ignition voltage

• A short to any 5 volts reference

Repair the circuit(s) as necessary.

Did you find and correct the condition?

—

Go to Step 13

Go to Step 12

Test the low reference circuit between the
ECM (pin 17 of E-90) and the BARO sensor
(pin 1 of E-40) for an open circuit or high
resistance.

Repair the circuit(s) as necessary.

Did you find and correct the condition?

—

Go to Step 13

Go to Step 10

6E-296 ENGINE CONTROL SYSTEM (4JK1/4JJ1)

Inspect for an intermittent and for a poor
connection at the harness connector of the
BARO sensor (pin 1 of E-40).

Repair the connection(s) as necessary.

Did you find and correct the condition?

—

Go to Step 13

Go to Step 11

Turn OFF the ignition.

Disconnect the ECM harness connector.

Inspect for an intermittent and for a poor
connection at the harness connector of the
ECM (pin 17 of E-90).

Repair the connection(s) as necessary.

Did you find and correct the condition?

—

Go to Step 13

Go to Step 12

Replace the BARO sensor. Refer to BARO Sensor
Replacement.

Did you complete the replacement?

—

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 13

—

Reconnect all previously disconnected
harness connector(s).

Clear the DTCs with a scan tool.

Turn OFF the ignition for 30 seconds.

Start the engine.

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 2

Go to Step 14

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

ENGINE CONTROL SYSTEM (4JK1/4JJ1) 6E-297

DTC P2621 or P2622 (Flash Code 94)

Circuit Description

The accelerator pedal position (APP) sensor is
mounted on the accelerator pedal control assembly.
The analogue APP signals are converted by the ECM
into a pulse width modulation (PWM) signal. This
converted signal is sent from the ECM to the TCM to
determine appropriate shift points depending on the
accelerator pedal pressing amount. If the ECM detects
an improper voltage level on the APP PWM signal
circuit, DTC P2621 or P2622 will set.

Condition for Running the DTC

• The battery voltage is more than 9 volts.

• The ignition switch is ON.

Condition for Setting the DTC

• The ECM detects a low voltage condition on the

APP PWM signal circuit for longer than 3 seconds.
(DTC P2621)

• The ECM detects a high voltage condition on the

APP PWM signal circuit for longer than 3 seconds.
(DTC P2622)

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.

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 P2621

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.

Does the DTC fail this ignition?

—

Go to Step 3

Go to Diagnostic

Aids

Turn OFF the ignition.

Back probe a DMM between the accelerator
pedal position (APP) signal circuit of the TCM
harness connector (pin 16 of C-94) and a
known good ground.

Turn ON the ignition, with the engine OFF.

Is the DMM voltage more than the specified value?

10.0 volts

Go to Step 6

Go to Step 4

Is the DMM voltage more than the specified value
at Step 3?

2.0 volts

Go to Step 7

Go to Step 5

Repair the short to ground between the ECM (pin
56 of C-58) and the TCM (pin 16 of C-94).

Did you complete the repair?

—

Go to Step 11

—

Test the signal circuit between the ECM (pin
56 of C-58) and the TCM (pin 16 of C-94) for
an open circuit or high resistance.

Repair the circuit(s) as necessary.

Did you find and correct the condition?

—

Go to Step 11

Go to Step 8

6E-298 ENGINE CONTROL SYSTEM (4JK1/4JJ1)

Circuit/ System Testing DTC P2622

Turn OFF the ignition.

Disconnect the TCM harness connector.

Inspect for an intermittent and for a poor
connection at the harness connector of the
TCM (pin 16 of C-94).

Repair the connection(s) as necessary.

Did you find and correct the condition?

—

Go to Step 11

Go to Step 9

Turn OFF the ignition.

Disconnect the ECM harness connector.

Inspect for an intermittent and for a poor
connection at the harness connector of the
ECM (pin 56 of C-58).

Repair the connection(s) as necessary.

Did you find and correct the condition?

—

Go to Step 11

Go to Step 10

Important: Replacement TCM must be
programmed.
Replace the TCM. Refer to TCM Replacement.

Did you complete the replacement?

—

Go to Step 11

—

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

Did you complete the replacement?

—

Go to Step 11

—

Reconnect all previously disconnected
harness connector(s).

Clear the DTCs with a scan tool.

Turn OFF the ignition for 30 seconds.

Start the engine.

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

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

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.

Does the DTC fail this ignition?

—

Go to Step 3

Go to Diagnostic

Aids

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