Isuzu D-Max / Isuzu Rodeo (TFR/TFS). Manual — part 64

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

6E–251

Diagnostic Trouble Code (DTC) P1120 (Symptom Code D) (Flash Code 21)

Pedal/Throttle Position Sensor Brake Switch Error

Step

Action

Value(s)

Yes

No

1

Was the “On-Board Diagnostic (OBD) System Check”
performed?

—

Go to Step 2

Go to On Board

Diagnostic

(OBD) System

Check

2

1. Connect the Tech 2.

2. Review and record the failure information.

3. Select “F0: Read DTC Infor As Stored By ECU” in

“F0: Diagnostic Trouble Codes”.

Is the DTC P1120 (Symptom Code D) stored as
“Present Failure”?

—

Go to Step 3

Refer to

Diagnostic Aids

and Go to Step

3

3

1. Using the Tech 2, ignition “On” and engine “Off”.

2. Select “F1: Clear DTC Information” in “F0:

Diagnostic Trouble Codes” with the Tech 2 and
clear the DTC information.

3. Operate the vehicle and monitor the “F0: Read

DTC Infor As Stored By ECU” in the “F0:
Diagnostic Trouble Codes”.

Was the DTC P1120 (Symptom Code D) stored in this
ignition cycle?

—

Go to Step 4

Refer to

Diagnostic Aids

and Go to Step

4

4

Visually check the TPS.
Check for the following conditions.

• Accelerator pedal sticking.
If a problem is found, repair as necessary.
Was the problem found?

—

Verify repair

Go to Step 5

5

1. Using the Tech 2, ignition “On” and engine “Off”.

2. Monitor the “Throttle Position” in the data display.

Does the Tech 2 indicate correct “Throttle Position”
from 0% to 100% depending on accelerator pedal
operation?

—

Go to Step 7

Go to Step 6

6

1. Using the Tech 2, ignition “On” and engine “Off”.

2. Monitor the “Throttle Position” in the data display.

3. Adjust the TPS within 0% to 100%.

Was the problem solved?

—

Verify repair

Go to Step 11

7

1. Using the Tech 2, ignition “On” and engine “Off”.

2. Monitor the “Brake Switch 1” and “Brake Switch 2”

in the data display.

Does the Tech 2 indicate “Inactive” when the brake
pedal was not stepped on?

—

Go to Step 13

Go to Step 8

8

Adjust the brake switch.
Was the problem solved?

—

Verify repair

Go to Step 9

9

Substitute a known good brake switch and recheck.
Was the problem solved?

—

Go to Step 10

Go to Step 13

10

Replace the brake switch.
Is the action complete?

—

Verify repair

—

11

Substitute a known good TPS and recheck.
Was the problem solved?

—

Go to Step 12

Go to Step 13

12

Replace the TPS.
Is the action complete?

—

Verify repair

—

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

13

Is the ECM programmed with the latest software
release?
If not, download the latest software to the ECM using
the “SPS (Service Programming System)”.
Was the problem solved?

—

Verify repair

Go to Step 14

14

Replace the ECM.
Is the action complete?
IMPORTANT: The replacement ECM must be
programmed. Refer to section of the Service
Programming System (SPS) in this manual.
Following ECM programming, the immobiliser system
(if equipped) must be linked to the ECM. Refer to
section 11 “Immobiliser System-ECM replacement” for
the ECM/Immobiliser linking procedure.

—

Verify repair

—

Step

Action

Value(s)

Yes

No

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

6E–253

Diagnostic Trouble Code (DTC) P1120 (Symptom Code E) (Flash Code 21)

Pedal/Throttle Position Sensor Idle Position Switch Error

Step

Action

Value(s)

Yes

No

1

Was the “On-Board Diagnostic (OBD) System Check”
performed?

—

Go to Step 2

Go to On Board

Diagnostic

(OBD) System

Check

2

1. Connect the Tech 2.

2. Review and record the failure information.

3. Select “F0: Read DTC Infor As Stored By ECU” in

“F0: Diagnostic Trouble Codes”.

Is the DTC P1120 (Symptom Code E) stored as
“Present Failure”?

—

Go to Step 3

Refer to

Diagnostic Aids

and Go to Step

3

3

1. Using the Tech 2, ignition “On” and engine “Off”.

2. Select “F1: Clear DTC Information” in “F0:

Diagnostic Trouble Codes” with the Tech 2 and
clear the DTC information.

3. Operate the vehicle and monitor the “F0: Read

DTC Infor As Stored By ECU” in the “F0:
Diagnostic Trouble Codes”.

Was the DTC P1120 (Symptom Code E) stored in this
ignition cycle?

—

Go to Step 4

Refer to

Diagnostic Aids

and Go to Step

4

4

Visually check the TPS.
Was the problem found?

—

Go to Step 8

Go to Step 5

5

1. Using the Tech 2, ignition “On” and engine “Off”.

2. Monitor the “Throttle Position” in the data display.

Does the Tech 2 indicate correct “Throttle Position”
from 0% to 100% depending on accelerator pedal
operation?

—

Go to Step 7

Go to Step 6Go

to Step 6

6

1. Using the Tech 2, ignition “On” and engine “Off”.

2. Monitor the “Throttle Position” in the data display.

3. Adjust the TPS within 0% to 100%.

Was the problem solved?

—

Verify repair

Go to Step 8

7

1. Using the Tech 2, ignition “On” and engine “Off”.

2. Monitor the “Idle Switch” in the data display.

Does the Tech 2 indicate “Inactive” when the
accelerator pedal was stepped on?

—

Go to Step 10

Go to Step 8

8

Substitute a known good TPS and recheck.
Was the problem solved?

—

Go to Step 9

Go to Step 10

9

Replace the TPS.
Is the action complete?

—

Verify repair

—

10

Is the ECM programmed with the latest software
release?
If not, download the latest software to the ECM using
the “SPS (Service Programming System)”.
Was the problem solved?

—

Verify repair

Go to Step 11

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

11

Replace the ECM.
Is the action complete?
IMPORTANT: The replacement ECM must be
programmed. Refer to section of the Service
Programming System (SPS) in this manual.
Following ECM programming, the immobiliser system
(if equipped) must be linked to the ECM. Refer to
section 11 “Immobiliser System-ECM replacement” for
the ECM/Immobiliser linking procedure.

—

Verify repair

—

Step

Action

Value(s)

Yes

No