ignition ISUZU TF SERIES 2004 Workshop Manual

3.5L ENGINE DRIVEABILITY AND EMISSIONS 6E-293
DIAGNOSTIC TROUBLE CODE (DTC) P0601 (FLASH CODE 51)
CONTROL MODULE MEMORY CHECKSUM

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)
51 P0601 A Control Module
Memory Checksum ECM memory area error. Engine control disabled.


CIRCUIT DESCRIPTION
The engine control module (ECM) used in this vehicle
utilizes an electrically erasable programmable read-only
memory (EEPROM). The EEPROM contains program
information and the calibrations required for engine,
transmission, and engine diagnostics operation.
Unlike the PROM used in past applications, the
EEPROM is not replaceable.

DIAGNOSTIC AIDS
 DTC P0601 indicates that the contents of the
EEPROM have changed since the ECM was
programmed. The only possible repair is ECM
replacement.


Diagnostic Trouble Code (DTC) P0601 (Flash Code 51)
Control Module Memory Checksum
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 P0601 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 P0601 stored in this ignition cycle?
- Go to Step 4 Refer to
Diagnostic Aids
4
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 5

6E-298 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P1508 (Flash Code 22) Idle Air
Control System Low/Closed
Diagnostic Trouble Code (DTC) P1509 (Flash Code 22) Idle Air
Control System High/Open
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 P1508 or P1509 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 P1508 or P1509 stored in this ignition
cycle?
- Go to Step 4 Refer to
Diagnostic Aids
and Go to Step 4
4
Check for the following conditions.

Objects blocking the Idle Air Control (IAC) Valve.

Objects blocking the throttle valve.

Vacuum leaking at throttle body.
If a problem is found, repair as necessary.
Was the problem found?
- Verify repair Go to Step 5
5
Check for poor/faulty connection at the IAC Valve or
ECM connector.
If a poor/faulty connection is found, repair the faulty
terminal.
Was the problem found?
E-61(B)







E-70






- Verify repair Go to Step 6

3.5L ENGINE DRIVEABILITY AND EMISSIONS 6E-299
Step Action Value (s) Yes No
6
Remove the IAC Valve and visually check.
Was the problem found?
- Go to Step 12 Go to Step 7
7
Using the DVM and check the IAC Valve coil at IAC
Valve.
1. Ignition "Off", engine "Off".
2. Disconnect the IAC Valve connector.
3. Check the coil resistance.
Does the tester indicate standard resistance as shown
in the following table?
IAC Valve














Measurement Terminal Resistance ()
1 - 2 Approximately 50
2 - 3 Approximately 50
1 – 3 Approximately 100
4 - 5 Approximately 50
5 - 6 Approximately 50
4 - 6 Approximately 100
-
Go to Step 8
Go to Step 12
8
Using the DVM and check the IAC Valve power supply
circuit.
1. Ignition "Off", engine "Off".

2. Disconnect the IAC Valve connector and ECM
main relay
3. Check the circuit for open circuit.
Was the problem found?
X-13E-70











-
Repair faulty
harness and
verify repair
Go to Step 9

6E-300 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Step Action Value (s) Yes No
9

Using the DVM and check the IAC Valve circuit.
Breaker box is available:
1. Ignition "Off", engine "Off".
2. Install the breaker box as type B. (ECM connection)
3. Using the Tech 2, ignition "On" and engine "Off".
4. Select the "Miscellaneous Test" and perform the
"IAC Control" in the "IAC System".
5. Operate the Tech 2 in accrodance with procedure.
Does the DVM indicate correct characteristic as
shown in the following table, when the IAC Valve is
operating step by step?
B13B14 Breaker BoxB17 B16
VVVV


Measurement Point IACV steps at 0, 20, 40,
160 IACV steps at 10, 30, 50,
150
Coil A High (Breaker Box 53 & GND) Less than 1V Battery voltage
Coil A Low (Breaker Box 56 & GND) Battery voltage Less than 1V
Coil B High (Breaker Box 54 & GND) Less than 1V Battery voltage
Coil B Low (Breaker Box 57 & GND) Battery voltage Less than 1V

3.5L ENGINE DRIVEABILITY AND EMISSIONS 6E-301
Step Action Value (s) Yes No
Breaker box is not available:
1. Using the Tech 2, ignition "On" and engine "Off".
2. Select the "Miscellaneous Test" and perform the
"IAC Control" in the "IAC System".
3. Operate the Tech 2 in accordance with procedure.
Does the DVM indicate correct characteristic as
shown in the following table, when the IAC Valve is
operating step by step?
E-61(B)
VVVV









Measurement Point IACV steps at 0, 20, 40,
160 IACV steps at 10, 30, 50,
150
Coil A High (ECM E61 connector 13 & GND) Less than 1V 10 - 14.5 V
Coil A Low (ECM E61 connector 16 & GND) 10 - 14.5 V Less than 1V
Coil B High (ECM E61 connector 14 & GND) Less than 1V 10 - 14.5 V
Coil B Low (ECM E61 connector 17 & GND) 10 - 14.5 V Less than 1V
-
Go to Step 14 Fixed at less than
1V: Go to Step
10
Fixed at battery
voltage: Go to
Step 11

6E-302 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Step Action Value (s) Yes No
10
Using the DVM and check the IAC Valve 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 the IAC Valve connector.
4. Check the circuit for open or short to ground circuit.
Was the problem found?
B13B14 Breaker BoxB17 B16
E-70













B13B14 Breaker BoxB17 B16









Breaker box is not available:
1. Ignition "Off", engine "Off".
2. Disconnect the IAC Valve connector.
3. Check the circuit for open or short to ground circuit.
Was the problem found?
E-61(B)
E-70




















E-61(B)










- Repair faulty
harness and
verify repair Go to Step 14

3.5L ENGINE DRIVEABILITY AND EMISSIONS 6E-303
Step Action Value (s) Yes No
11
Using the DVM and check the IAC Valve circuit.
1. Ignition "On", engine "Off".
2. Disconnect the IAC Valve connector.
3. Check the circuit for short to power supply circuit.
Was the DVM indicate voltage?
E-70
VVVV






-
Repair faulty
harness and
verify repair
Go to Step 14
12
Substitute a known good IAC Valve and recheck.
Was the problem solved?
- Go to Step 13 Go to Step 14
13
Replace the IAC Valve.
Was the problem solved?
- Verify repair Go to Step 14
14
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 15
15
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-305
Diagnostic Trouble Code (DTC) P1601 (Flash Code 65) CAN Bus Off

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 P1601 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 P1601 stored in this ignition cycle?
- Go to Step 4 Refer to
Diagnostic Aids
and Go to Step 4
4
Check any accessory parts which may cause electric
interference.
Was the problem found?
- Remove the
accessory parts
and verify repair Go to Step 5
5
1. Using the Tech 2, ignition "On" and engine "Off".
2. Select "AW30-40LE" in the system selection menu
"Powertrain".
3. Select "Read DTC Info Ordered By Priority" in the
"Diagnositic Trouble Code".
Was the any DTC's P1767 or U2104 stored in this
ignition cycle?
- Refer to
"Automatic
Transmission
Workshop
Manual" & Go to
DTC Chart
P1767 or U2104 Go to Step 6
6
Check for poor/faulty connection at the TCM or ECM
connector. If a poor/faulty connection is found, repair
as necessary.
Was the problem found?
E-60(A)








- Verify repair Go to Step 7

6E-306 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Step Action Value (s) Yes No
7
Using the DVM and check the CAN BUS high circuit.
1. Ignition "Off", engine "Off".
2. Disconnect the TCM connector.
3. Ignition "On".
4. Check the circuit for short to power supply circuit.
Was the problem found?


V



-
Repair faulty
harness and
verify repair
Go to Step 8
8
Using the DVM and check the CAN BUS low circuit.
1. Ignition "Off", engine "Off".
2. Disconnect the TCM connector.
3. Ignition "On".
4. Check the circuit for short to power supply circuit.
Was the problem found?


V



-
Repair faulty
harness and
verify repair
Go to Step 9
9
Using the DVM and check the ECM CAN BUS circuit.
1. Ignition "Off", engine "Off".
2. Disconnect TCM connector.
3. Measure the resistance of ECM CAN BUS circuit.
Does the tester indicate standard resistance?






Approximately
120
Go to Step 14
Close to 0:
Go to Step 10
No resistance:
Go to Step 11

3.5L ENGINE DRIVEABILITY AND EMISSIONS 6E-307
Step Action Value (s) Yes No
10
Repair the open circuit between the ECM CAN BUS
high and low circuit.
Was the problem solved?
E-60(A)






- Verify repair Go to Step 15
11
Using the DVM and check the CAN BUS high 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 the TCM connector.
4. Check the circuit for open or short to ground circuit.
Was the problem found?
A10
Breaker Box