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Isuzu D-Max / Isuzu Rodeo (TFR/TFS). Manual - part 236

ENGINE DRIVEABILITY AND EMISSIONS

6E–185

Using the DVM and check the purge solenoid valve
power supply circuit.

1. Ignition “On”, engine “Off”.

2. Disconnect the purge solenoid valve connector.

3. Check the circuit for open circuit.

Was the DVM indicated specified value?

Battery
voltage

Go to Step 8

Go to Step 7

Repair the open or short to ground circuit between the
“Engine” fuse (15A) and purge solenoid valve.
Is the action complete?

—

Verify repair

Using the DVM and check the purge solenoid valve
solenoid signal circuit.
Breaker box is available:

1. Ignition “Off”, engine “Off”.

2. Install the breaker box as type A. (ECM

disconnected) Ref. 6E-80.

3. Disconnect the purge solenoid valve connector.

4. Check the circuit for open or short to ground

circuit.

Was the problem found?

Breaker box is not available:

1. Ignition “Off”, engine “Off”.

2. Disconnect the purge solenoid valve connector

and ECM connector.

3. Check the circuit for open or short to ground

circuit.

Was the problem found?

—

Repair faulty

harness and

verify repair

Go to Step 9

Step

Action

Value(s)

Yes

E-66

E-60(J1)

6E–186

ENGINE DRIVEABILITY AND EMISSIONS

Using the DVM and check the purge solenoid valve
signal circuit.

1. Ignition “On”, engine “Off”.

2. Disconnect the purge solenoid valve connector.

3. Check the circuit for short to battery voltage

circuit.

Was the DVM indicated battery voltage?

—

Repair faulty

harness and

verify repair

Go to Step 10

Substitute a known good purge solenoid valve and
recheck.
Was the problem solved?

—

Go to Step 11

Go to Step 12

Replace the purge solenoid valve.
Was the problem solved?

—

Verify repair

Go to Step 12

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 13

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

E-66

ENGINE DRIVEABILITY AND EMISSIONS

6E–187

DIAGNOSTIC TROUBLE CODE (DTC) P0502 VEHICLE SPEED SENSOR (VSS)

CIRCUIT LOW INPUT

Condition for setting the DTC and action taken when the DTC sets

Circuit Description

The vehicle speed sensor has a magnet rotated by the
transmission output shaft. Attached to the sensor is a
hall effect circuit that interacts with the magnetic field
created by the rotating magnet. A 12-volt operating
supply for the speed sensor hall circuit is supplied from
the meter fuse.

Diagnostic Aids

• Poor connection at ECM: Inspect harness connectors

for backed out terminals, improper mating, broken
locks, improperly formed or damaged terminals, and
poor terminal to wire connection.

Code

Type

DTC Name

DTC Setting Condition

Fail-Safe (Back Up)

P0502

Vehicle Speed Sensor Circuit Low
Input

1. No DTC relating to MAP sensor, TPS, ECT

sensor, injector control circuit and ignition
control circuit.

2. Engine is running.
3. Vehicle speed is below 3km/h in power con-

dition or 2km/h in deceleration condition.

ECM uses 0km/h condition as substitute.

Ign

Engine
Control
Module
(ECM)

Ignition
SW

µP

Meter
15A

Ign

Check
Engine

Sped

Meter

Tacho

Meter

0.85
YEL

0.8 YEL/GRN

0.5 BRN/YEL

CPU

0.5
WHT

J2-23

J2-25

0.5
BRN/
YEL

(–)

(+)

Vehicle
Speed
Sensor

J2-32

Imnobiliser
Control
Unit

6E–188

ENGINE DRIVEABILITY AND EMISSIONS

Diagnostic Trouble Code (DTC) P0502 Vehicle Speed Sensor Circuit Low Input

Step

Action

Value(s)

Yes

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

—

Go to Step 2

Go to On Board

Diagnostic

(OBD) System

Check

1. Connect the Tech 2.

2. Review and record the failure information.

3. Select “F0: Read DTC Infor By Priority” in “F0:

Diagnostic Trouble Code”.

Is the DTC P0502 stored as “Present Failure”?

—

Go to Step 3

Refer to

Diagnostic Aids

and Go to Step

1. Using the Tech2, ignition “On” and engine “Off”.

2. Select “Clear DTC Information” with the Tech2 and

clear the DTC information.

3. Operate the vehicle and monitor the “F5: Failed

This Ignition” in “F2: DTC Information”.

Was the DTC P0502 stored in this ignition cycle?

—

Go to Step 4

Refer to

Diagnostic Aids

and Go to Step

Check for poor/faulty connection at the VSS, meter,
immobiliser control unit (if equipped), ECM and other
connectors. If a poor/faulty connection is found, repair
the faulty terminal.
Was the problem found?

—

Verify repair

Go to Step 5

Remove the VSS from the housing case and visually
check.
Was the problem found?

—

Go to Step 19

Go to Step 6

9 10

C-56(J2)

B-68

B-24

E-44

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