Isuzu N-Series. Manual - part 438

6E-88 EMISSION AND ELECTRICAL DIAGNOSIS

Step

Action

Value

YES

NO

1

Was the “on-board diagnostic (OBD) system
check” performed?

—

Go to Step 2

Go to self diag 

system check

2

1. Ignition “OFF”
2. Disconnect the VSV from the wiring har-

ness connector.

3. Ignition “ON” Engine “OFF”
4. Using the Digital Voltmeter (DVM), check

for voltage on the “IC25” of the VSV har-
ness connector.

Does the DVM read the following value?

12 Volt or 24 

Volt

Go to Step 4

Go to Step 3

3

1. Check the suspect circuit between the

VSV connector and “Engine Ignition.”
Fuse for the following condition.

• A short to ground
• An open circuit

2. Repair if necessary.

Has DTC 35 been corrected?

—

Go to Step 8

—

4

Using the DVM, check the resistance of the
VSV.

Does the DVM read the following Value?

37 — 44

Ω (for 

12 Volt)

159 — 169

Ω 

(for 24 Volt)

Go to Step 5

Go to Step 6

5

1. Ignition “OFF”
2. Disconnect the ECM connector from

ECM.

3. Check the VSV circuit between the ECM

and VSV connector.

• A short to ground
• An open circuit

4. Repair if necessary.

Has DTC 35 been corrected?

—

Go to Step 8

Go to Step 7

6

Replace the VSV.

Is the action complete?

Go to Step 8

—

7

Replace the ECM.

Is the action complete?

—

Go to Step 8

—

8

1. Reconnect all the connectors removed.
2. Ignition “ON”, Engine “OFF”

Is DTC 35 all right under Scan Tool Check?

—

Go to Step 9

Go to Step 2

9

Is any current trouble other than DTC 35 dis-
played by scan tool?

—

Go to trouble code 

section

Trouble code clear

EMISSION AND ELECTRICAL DIAGNOSIS 6E-89

DTC-P36 Exhaust Gas Recirculation (EGR) Quick Cut Vacuum Switching Valve (VSV) Con-
trol Circuit High Voltage

N6A1204E

6E-90 EMISSION AND ELECTRICAL DIAGNOSIS

Appearance of Vacuum Switching Valve (VSV):
Exhaust Gas Recirculation (EGR) CUT Sensor
and Connector Name

VSV: EGR CUT

VSV: EGR CUT Connector

Measure Resistance at VSV: EGR CUT

Caution:
When measuring resistance with a circuit tester, be careful not to damage or deform the terminals.

N6A1205E

Legend

1. To VSV: EGR
2. 2 pin

Connector No

Signal

1

SIG

2

GND

N6A1190E

Legend

1. Circuit tester

3. Measure resistance between connector pin

2. Remove VSV wire harness

N6A1207E

EMISSION AND ELECTRICAL DIAGNOSIS 6E-91

Resistance value

Notice:
Resistance value is difference according to the engine temperature (condition of engine warming up).

Inspection Point

Resistance Value

(k

Ω)

Reference

Connector

Pin No.

2 pin Black

2 

←→ 1

37 to 44 (for 12 volt)

159 to 169 (for 24 volt)

SIG 

←→ GND

1 

←→ Body

∞

SIG 

←→ Body

Step

Action

Value

YES

NO

1

Was the “on-board diagnostic (OBD) system
check” performed?

—

Go to Step 2

Go to self diag 

system check

2

Using the DVM, check the resistance of the
VSV.

Does the DVM read the following Value?

37 — 44

Ω

(for 12 Volt)

159 — 169

Ω

(for 24 Volt)

Go to Step 3

Go to Step 4

3

1. Ignition “OFF”
2. Disconnect the ECM connector from

ECM.

3. Check the short to voltage of VSV circuit

between the ECM and VSV connector.

4. Repair if necessary.

Has DTC 36 been corrected?

—

Go to Step 6

Go to Step 5

4

Replace the VSV.

Is the action complete?

—

Go to Step 6

—

5

Replace the ECM.

Is the action complete?

—

Go to Step 6

—

6

1. Reconnect all the connectors removed.
2. Ignition “ON”, Engine “OFF”

Is DTC 36 all right under Scan Tool Check?

—

Go to Step 7

Go to Step 2

7

Is any current trouble other than DTC 36 dis-
played by scan tool?

—

Go to trouble code 

section

Trouble code clear