check engine ISUZU TF SERIES 2004 Workshop Manual

3.5L ENGINE DRIVEABILITY AND EMISSIONS 6E-261
Step Action Value (s) Yes No
8
Repair the open or short to ground circuit between the
ECM main relay and EGR valve.
Is the action complete?
- Verify repair -
9

Using the DVM and check the EGR valve solenoid
signal circuit.
Breaker box is available:
1. Ignition "Off", engine "Off".
2. Install the breaker box as type A (ECM
disconnected).
Refer to 6E-95 page.
3. Disconnect EGR valve connector.
4. Check the circuit for open, short to sensor ground
or short to ground circuit.
Was the problem found?
A5A22


Breaker Box
E-76







Breaker box is not available:
1. Ignition "Off", engine "Off".
2. Disconnect the EGR valve connector and ECM
connector.
3. Check the circuit for open, short to sensor ground
or short to ground circuit.
Was the problem found?
E-60(A)




E-76









-

Repair faulty
harness and
verify repair

Go to Step 10

6E-262 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Step Action Value (s) Yes No
10
Using the DVM and check the EGR valve solenoid
signal circuit.
1. Ignition "Off", engine "Off".
2. Disconnect the EGR valve connector.
3. Check the circuit for short to battery voltage circuit.
Was the DVM indicated battery voltage?
E-76
V




-
Repair faulty
harness and
verify repair
Go to Step 11
11
Substitute a known good EGR valve and recheck.
Was the problem solved?
- Go to Step 12 Go to Step 13
12
Replace the EGR valve.
Was the problem solved?
- Verify repair Go to Step 13
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 immobilizer system (if
equipped) must be linked to the ECM. Refer to section
11 “Immobilizer System-ECM replacement” for the
ECM/Immobilizer linking procedure.
- Verify repair -

3.5L ENGINE DRIVEABILITY AND EMISSIONS 6E-263
DIAGNOSTIC TROUBLE CODE (DTC) P0405 (FLASH CODE 32)
EGR CIRCUIT LOW



RUW46EMF000201

Condition For Setting The DTC and Action Taken When The DTC Sets
Flash
Code Code Type DTC Name DTC Setting Condition Fail-Safe (Back Up)
32 P0405 B EGR Circuit Low 1. No DTC relating to EGR circuit range/performance.
2. EGR solenoid valve on-duty ratio is more than 40%.
3. EGR position sensor output voltage is below 0.3V. No fail-safe function.

CIRCUIT DESCRIPTION
The engine control module (ECM) monitors the EGR
valve pintle position input to ensure that the valve
responds properly to command from the ECM. If curren
t
pintle position voltage indicates less than 0.3 V the ECM
will set DTC P0405.

DIAGNOSTIC AIDS
Check for the following conditions:
 Poor connection or damaged harness –Inspect the
wiring harness for damage. If the harness appears to
be OK, observe the EGR actual position display on
the Tech 2 while moving connectors and wiring
harnesses related to EGR valve. A change in the
display will indicate the location of the fault.

6E-264 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0405 (Flash Code 32)
EGR Circuit Low

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 By Priority" in "F0:
Diagnostic Trouble Code".
Is the DTC P0405 stored as "Present Failure"?
- Go to Step 3 Refer to
Diagnostic Aids
and Go to Step 3
3
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 P0405 stored in this ignition cycle?
- Go to Step 4 Refer to
Diagnostic Aids
and Go to Step 4
4
Check for poor/faulty connection at the EGR valve or
ECM connector. If a poor/faulty connection is found,
repair as necessary.
Was the problem found?
E-60(A)
E-76






- Verify repair Go to Step 5
5
Visually check the EGR valve.
Was the problem found?
- Go to Step 10 Go to Step 6

3.5L ENGINE DRIVEABILITY AND EMISSIONS 6E-265
Step Action Value (s) Yes No
6
Using the DVM and check the EGR valve position
sensor.
1. Ignition "Off", engine "Off".
2. Disconnect EGR valve connector.
3. Measure the resistance of EGR valve position
sensor.
Does the tester indicate standard resistance as shown
in the following table?
EGR Valve



EGR Valve









Measurement Terminal Resistance ()
2 – 3 Approximately 1.1k
3 – 4 Approximately 4.5k
2 - 4 Approximately 4.7k
Standard
resistance
Go to Step 7
Go to Step 10
7
Using the DVM and check the EGR valve position
sensor power supply circuit.
1. Ignition "On", engine "Off".
2. Disconnect the EGR valve connector.
3. Check the circuit for open or short to ground circuit.
Was the DVM indicated specified value?
E-76
V



Approximately
5.0V
Go to Step 9
Go to Step 8
8
Repair the open or short to ground circuit between the
ECM and EGR valve position sensor circuit.
Was the problem solved?
E-76


E-60(A)


- Verify repair Go to Step 12

6E-266 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Step Action Value (s) Yes No
9

Using the DVM and check the EGR valve position
sensor signal circuit.
Breaker box is available:
1. Ignition "Off", engine "Off".
2. Install the breaker box as type A (ECM
disconnected).
Refer to 6E-95 page.
3. Disconnect EGR valve connector.
4. Check the circuit for open, short to sensor ground
or short to ground circuit.
Was the problem found?
E-76





A9A22


Breaker Box




Breaker box is not available:
1. Ignition "Off", engine "Off".
2. Disconnect the EGR valve connector and ECM
connector.
3. Check the circuit for open, short to sensor ground
or short to ground circuit.
Was the problem found?
E-76


E-60(A)










-

Repair faulty
harness and
verify repair

Go to Step 10
10
Substitute a known good EGR valve and recheck.
Was the problem solved?
- Go to Step 11 Go to Step 12
11
Replace the EGR valve.
Is the action complete?
- Verify repair -

6E-268 3.5L ENGINE DRIVEABILITY AND EMISSIONS
DIAGNOSTIC TROUBLE CODE (DTC) P0406 (FLASH CODE 32)
EGR CIRCUIT HIGH



RUW46EMF000201

Condition For Setting The DTC and Action Taken When The DTC Sets
Flash
Code Code Type DTC Name DTC Setting Condition Fail-Safe (Back Up)
32 P0406 B EGR Circuit High 1. No DTC relating to EGR circuit range/performance.
2. EGR solenoid valve on-duty ratio is below 40%.
3. EGR position sensor output voltage is more than 4.6V. No fail-safe function.


CIRCUIT DESCRIPTION
The engine control module (ECM) monitors the EGR
valve pintle position input to ensure that the valve
responds properly to command from the ECM. If curren
t
pintle position voltage indicates more than 4.6 V the
ECM will set DTC P0406.

DIAGNOSTIC AIDS
Check for the following conditions:
 Poor connection or damaged harness –Inspect the
wiring harness for damage. If the harness appears to
be OK, observe the EGR actual position display on
the Tech 2 while moving connectors and wiring
harnesses related to EGR valve. A change in the
display will indicate the location of the fault.

3.5L ENGINE DRIVEABILITY AND EMISSIONS 6E-269
Diagnostic Trouble Code (DTC) P0406 (Flash Code 32)
EGR Circuit High

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 By Priority" in "F0:
Diagnostic Trouble Code".
Is the DTC P0406 stored as "Present Failure"?
- Go to Step 3 Refer to
Diagnostic Aids
and Go to Step 3
3
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 P0406 stored in this ignition cycle?
- Go to Step 4 Refer to
Diagnostic Aids
and Go to Step 4
4
Check for poor/faulty connection at the EGR valve or
ECM connector. If a poor/faulty connection is found,
repair as necessary.
Was the problem found?
E-60(A)
E-76





- Verify repair Go to Step 5
5
Visually check the EGR valve.
Was the problem found?
- Go to Step 12 Go to Step 6

6E-270 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Step Action Value (s) Yes No
6
Using the DVM and check the EGR valve position
sensor.
1. Ignition "Off", engine "Off".
2. Disconnect EGR valve connector.
3. Measure the resistance of EGR valve position
sensor.
Does the tester indicate standard resistance as shown
in the following table?
EGR Valve



EGR Valve









Measurement Terminal Resistance ()
2 – 3 Approximately 1.1k
3 – 4 Approximately 4.5k
2 - 4 Approximately 4.7k
Standard
resistance
Go to Step 7
Go to Step 12
7
Using the DVM and check the EGR position sensor
power supply circuit.
1. Ignition "On", engine "Off".
2. Disconnect the EGR valve connector.
3. Check the circuit for short to voltage circuit.
Was the DVM indicated specified value?
E-76
V



Approximately
5.0V
Go to Step 9
Go to Step 8
8
Repair the short to voltage circuit between the ECM
and EGR valve.
Was the problem solved?
E-76


E-60(A)


- Verify repair Go to Step 14

3.5L ENGINE DRIVEABILITY AND EMISSIONS 6E-271
Step Action Value (s) Yes No
9
Using the DVM and check the EGR position sensor
signal circuit.
1. Ignition "On", engine "Off".
2. Disconnect the EGR valve connector.
3. Check the circuit for short to power supply circuit.
Was the DVM indicated specified value?
E-76
V




Less than 1V
Go to Step 10
Repair faulty
harness and
verify repair
10
Using the DVM and check the EGR position sensor
ground circuit.
1. Ignition "On", engine "Off".
2. Disconnect the EGR valve connector.
3. Check the circuit for short to power supply circuit.
Was the DVM indicated specified value?
E-76
V




Less than 1V
Go to Step 11
Repair faulty
harness and
verify repair