Isuzu engine C22NE / 22LE / 20LE. Manual - part 62

DRIVEABILITY AND EMISSIONS  6E1-77

Diagnosis

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1

7

5

6

2

3

4

Legend

(1) Intake Manifold
(2) Fuel Vapor Purge Control Solenoid

(3) Fuel Vapor Canister

(4) Check and Relief valve

(5) Fuel Tank
(6) Pressure/ Vacuum Vented
(7) Rollover Valve

Visual Check of Canister

Cracked or damaged, replace canister.

6E1-78  DRIVEABILITY AND EMISSIONS

Evaporative Emission Canister Purge Control Solenoid Valve Check (If applicable)

ENGINE

CONTROL

MODULE

(ECM)

ENGINE FUSE

15A

IGNITION

EVAPORETIVE

EMISSION

CANISTER PURGE

SOLENOID

CONTROL DRIVER

EVAPORATIVE

EMISSION

CANISTER

PURGE CONTLOL

SOLENOID VALVE

1

2

N.C.

MANIFOLD

VACUUM

TO CANISTER

Circuit Description:

The EVAP canister purge is controlled by a solenoid

valve that allows the manifold vacuum to purge the

canister. The engine control module (ECM) supplies a

ground to energize the solenoid valve (purge on). The

EVAP purge solenoid control is pulse- width

modulated (PWM) (turned on and off several times a

second). The duty cycle (pulse width) is determined by

engine operating conditions including load, throttle

position, coolant temperature and ambient

temperature. The duty cycle is calculated by the ECM.

The output is commanded when the appropriate

conditions have been met. These condi-tions are:
• The engine is fully warmed up.
• The engine has been running for a specified time.
• The IAT reading is above 10°C (50°F).
The EVAP purge vacuum switch is a normally closed

switch positioned in the purge line between the

canister and the EVAP purge control solenoid valve.

A continuous purge condition with no purge

commanded by the ECM will set a DTC62.
Poor idle, stalling and poor driveability can be caused
by:

• A malfunctioning purge solenoid.
• A damaged canister.
• Hoses that are split, cracked, or not connected

properly.

Test Description:

Numbers below refer to circled numbers on the

diagnostic chart.

1. Check to see if the solenoid is opened or closed.

The solenoid is normally de-energized in this step,

so it should be closed.

2. Check to determine if solenoid was open due to

electrical CKT problem or defective solenoid.

3. Completes functional check by grounding test

terminal. This should normally energize the

solenoid opening the valve which should allow the

vacuum to drop (purge “ON“).

Diagnostic Aids:

Make a visual check of vacuum hose(s). Check

throttle body for possible cracked, or plugged vacuum

block.

Malfunction indicator lamp for possible mechanical

problem.

DRIVEABILITY AND EMISSIONS  6E1-79

General Description

Legend

(1) Filler Cap

(2) Fuel Tank

(3) Rollover Valve

(4) Fuel Pump

(5) Fuel Filter

(6) Fuel Rail

(7) Intake Manifold

(8) Fuel Pressure Regulator

 (9) Duty Solenoid Valve (Evap. Purge Control

Solenoid)

(10) Throttle Valve

(11) Canister

(12) Check and Relief Valve

(13) Drain Hose

(14) 2 Way Valve

6E1-80  DRIVEABILITY AND EMISSIONS

ECM Diagnostic Trouble Codes

The following table lists the diagnostic trouble codes
supported a Tech 2 and to flash. If any DTCs not listed
here are displayed by a Tech 2, the Tech 2 data may

be faulty; notify the Tech 2 manufacturer of any DTCs
displayed that are not included in the following table.

ECM Diagnostic Trouble Codes

DTC

using a

Tech 2

Flash DTC

Description

Illuminate MIL

22

22

Throttle position low

yes

21

21

Throttle position high

yes

13

13

Oxygen sensor not ready (If applicable)

yes

44

44

Oxygen sensor too lean (If applicable)

yes

45

45

Oxygen sensor rich too long (If applicable)

yes

14

14

Coolant High

yes

15

15

Coolant Low

yes

16

16

Knock sensor disconnected circuit open

yes

18

18

Digital Signal to Noise Enhancement Filter failure

yes

19

19

58X signal incorrect

yes

24

24

Vehicle Speed Senser fault

yes

33

33

Manifold Absolute Pressure Sensor too high

yes

34

34

MAP too low

yes

49

49

Batt voltage too high

yes

69

69

Intake Air Temp. Sensor too high

yes

71

71

IAT too low

yes

17

17

Injector malf

yes

41

41

Coil Driver B short to battery

yes

42

42

Coil Driver A short to battery

yes

63

63

Coil Driver B short to ground

yes

64

64

Coil Driver A short to ground

yes

35

35

Idle Air Control Value error

yes

56

56

Check Engine Lamp low error

yes

57

57

Check Engine Lamp high error

yes

61

61

Charcoal Canister Purge low error (If applicable)

yes

62

62

CCP Solenoid high error (If applicable)

yes

87

87

AC Clutch relay low error

yes

88

88

AC Clutch relay high error

yes

93

93

Quad Driver Sub Module error

yes

51

51

EPROM error

yes

55

55

EEPROM error

yes

91

91

Tacho out low error

yes

92

92

Tacho out high error

yes

29

29

Fuel Pump relay shorted to ground

yes

32

32

Fuel Pump relay shorted to battery

yes