check engine ISUZU TF SERIES 2004 Workshop Manual

3.5L ENGINE DRIVEABILITY AND EMISSIONS 6E-139
Flash
Code Code Type DTC Name DTC Setting Condition Fail-Safe (Back Up) Recovery Condition Related Failure Parts Related
ECM Pin
No. Related
Multiple
DTC 24 P0500 B Vehicle Speed Sensor Circuit
Range/Performance 1. Engine speed is below 5000rpm.
2. Under fuel cut operation.
3. Vehicle speed sensor output is below 1km/h.
Above conditions are met for 4 seconds. The ECM use 10km/h
condition as substitute. Vehicle speed sensor output is
more than 2km/h. 1. Sensor harness open circuit, short to ground
circuit or short to voltage circuit.
2. Poor connector connection.
3. Electrical interference.
4. Magnetic interference.
5. VSS malfunction.
6. ECM malfunction. B32 -
P0562 D System Voltage Low Battery voltage is below 6V for more than 20
seconds. 1. Battery power feed harness open circuit or
short to ground circuit.
2. ECM ground harness open or poor
connection.
3. Poor connector connection.
4. Battery malfunction.
5. Charge system malfunction.
6. ECM malfunction. - -
66
P0563 A System Voltage High Battery voltage is above 16V for more than 20
seconds. No fail-safe function. Battery voltage is between 6V
and 16V.
1. Charge system malfunction.
2. Battery jump start cable misconnect.
3. ECM malfunction. - - 51 P0601 A Control Module Memory
Checksum ECM memory area error. Engine control disabled. Memory are is OK.
1. ECM malfunction. - -
P0602 - ECU Programming Error ECM memory area error. Engine control disabled. Memory are is OK.
1. ECM is not programmed. - -

3.5L ENGINE DRIVEABILITY AND EMISSIONS 6E-141
Flash
Code Code Type DTC Name DTC Setting Condition Fail-Safe (Back Up) Recovery Condition Related Failure Parts Related
ECM Pin
No. Related
Multiple
DTC
P1626 - Immobilizer No Signal No response from immobilizer control unit.
1. ECM and immobilizer control unit
communication circuit open circuit, short to
ground circuit or short to voltage circuit.
2. Electrical interference.
3. Magnetic interference.
4. ECM malfunction.
5. Immobilizer control unit malfunction.
6. Transponder key malfunction. B18/
B32 B**** P1631 - Immobilizer Wrong Signal Received response is not correct.
1. ECM malfunction.
2. Immobilizer control unit malfunction.
3. Transponder key malfunction. - B**** P1648 - Wrong Security Code Entered Received incorrect security code.
1. ECM malfunction.
2. Immobilizer control unit malfunction.
3. Transponder key malfunction. - B****
67
P1649 - Immobilizer Function Not
Programmed Immobilizer function is not programmed in the
ECM. 1. Engine does not start.
2. Check engine lamp flash.
No recovery
ECM malfunction. - B****

6E-146 3.5L ENGINE DRIVEABILITY AND EMISSIONS
CIRCUIT DESCRIPTION
The mass air flow (MAF) sensor measures the amount
of air which passes through it into the engine during a
given time. The Engine Control Module (ECM) uses the
mass air flow information to monitor engine operating
conditions for fuel delivery calculations. A large quantity
of air entering the engine indicates an acceleration o
r
high load situation, while a small quantity or air indicates
deceleration or idle.
The MAF sensor produces a frequency signal which
can be monitored using a Tech 2. The frequency will
vary within a range of around 4 to 7 g/s at idle to around
25 to 40 g/s at maximum engine load. DTC P0101 will
be set if the signal from the MAF sensor does not match
a predicted value based on throttle position and engine
RPM.
DIAGNOSTIC AIDS
An intermittent may be caused by the following:
 Poor connections.
 Mis-routed harness.
 Rubbed through wire insulation.
 Broken wire inside the insulation.
Refer to Intermittents under service category
Symptoms.
Any un-metered air may cause this DTC to set. Check
for the following:
 The duct work at the MAF sensor for leaks.
 An engine vacuum leak.
 The PCV system for vacuum leaks.
 An incorrect PCV valve.
 The engine oil dip stick not fully seated.
 The engine oil fill cap loose or missing.


Diagnostic Trouble Code (DTC) P0101 (Flash Code 61)
Mass Air Flow Sensor Circuit Range/Performance
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 P0101 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 P0101 stored in this ignition cycle?
- Go to Step 4 Refer to
Diagnostic Aids
and Go to Step 4

3.5L ENGINE DRIVEABILITY AND EMISSIONS 6E-147
Step Action Value (s) Yes No
4
1. Using the Tech 2, ignition "On" and engine "On".
2. Monitor the "Mass Air Flow" in the data display.
Does the Tech 2 indicate correct "Mass Air Flow" as
shown in the following graph, when engine speed is
increasing little by little?
Characteris tic of MAF Sens or -Ref erence (No Engine Load)-
0 5 10 15 20 25 30 35 40 45 50
0 500 1000 1500 2000 2500 3000 3500 4000 4500 5000
Eng i ne Speed ( r pm) ( T ech2 R eadi ng )
Mass Air Flow (g/s)
( T ec h2 R eadi ng)
- Go to Step 6 Go to Step 5
5
Remove the MAF & IAT sensor assembly and check
for the following conditions.

Objects blocking the air cleaner.

Objects blocking the MAF sensor.

Objects blocking the throttle valve.

Vacuum leaking at intake duct.

Vacuum leaking at throttle body.
If a problem is found, repair as necessary.
Was the problem found?
- Verify repair Go to Step 6
6
Check for poor/faulty connection at the MAF sensor or
ECM connector. If a poor/faulty connection is found,
repair as necessary.
Was the problem found?


 E-61(B)
E-63






- Verify repair Go to Step 7
7
Remove the MAF & IAT sensor assembly and visually
check.
Was the problem found?
- Go to Step 11 Go to Step 8

6E-148 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Step Action Value (s) Yes No
8
Using the DVM and check the MAF sensor signal
circuit.
1. Ignition "Off", engine "Off".
2. Disconnect the MAF sensor connector.
3. Ignition "On".
4. Check the circuit for short to power supply circuit.
Was the DVM indicated specified value?
V

E-63


Less than 1V
Go to Step 9
Repair faulty
harness and
verify repair
9
Check any accessory parts which may cause electric
interference.
- Remove the
accessory parts
and verify repair
Go to Step 10
10
Check the shield wire for open or short circuit.
Was the problem found?
- Verify repair Go to Step 11
11
Substitute a known good MAF & IAT sensor assembly
and recheck.
Was the problem solved?
- Go to Step 12 Go to Step 13
12
Replace the MAF & IAT sensor assembly.
Is the action complete?
- Verify repair
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 -

6E-150 3.5L ENGINE DRIVEABILITY AND EMISSIONS
CIRCUIT DESCRIPTION
The mass air flow (MAF) sensor measures the amount
of air which passes through it into the engine during a
given time. The Engine Control Module (ECM) uses the
mass air flow information to monitor engine operating
conditions for fuel delivery calculations. A large quantity
of air entering the engine indicates an acceleration o
r
high load situation, while a small quantity of air indicates
deceleration or idle.
The MAF sensor produces a frequency signal which
can be monitored using a Tech 2. The frequency will
vary within a range of around 5 to 8 g/s at idle to around
25 to 40 g/s at maximum engine load. DTC P0102 will
be set if the signal from the MAF sensor is below the
possible range of a normally operating MAF sensor.
.

DIAGNOSTIC AIDS
Check for the following conditions:
 Poor connection at ECM – Inspect harness
connectors for backed-out terminals, imprope
r
mating, broken locks, improperly formed or damaged
terminals, and poor terminal-to-wire connection.
 Misrouted harness – Inspect the MAF senso
r
harness to ensure that it is not routed too close to
high voltage wires.
 Damaged harness –Inspect the wiring harness fo
r
damage. If the harness appears to be OK, observe
the Tech 2 while moving connectors and wiring
harnesses related to the MAF sensor. A change in
the display will indicate the location of the fault.
If DTC P0102 cannot be duplicated, the information
included in the Failure Records data can be useful in
determining vehicle mileage since the DTC was last set


Diagnostic Trouble Code (DTC) P0102 (Flash Code 61) Mass Air Flow Sensor
Circuit Low Input
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 P0102 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 P0102 stored in this ignition cycle?
- Go to Step 4 Refer to
Diagnostic Aids
and Go to Step 4

3.5L ENGINE DRIVEABILITY AND EMISSIONS 6E-151
Step Action Value (s) Yes No
4
Check for poor/faulty connection at the MAF sensor or
ECM connector. If a poor/faulty connection is found,
repair as necessary.
Was the problem found?


 E-61(B)
E-63






- Verify repair Go to Step 5
5
Remove the MAF & IAT sensor assembly and visually
check.
Was the problem found?
- Go to Step 8 Go to Step 6
6
Using the DVM and check the MAF 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-99 page.
3. Disconnect the MAF sensor connector.
4. Check the circuit for open, short to sensor ground
or short to ground circuit.
Was the problem found?
B20B39




Breaker Box

E-63

6E-152 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Step Action Value (s) Yes No

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




E-63





- Repair faulty
harness and
verify repair Go to Step 7
7
Using the DVM and check the MAF sensor power
supply circuit.
1. Ignition "Off", engine "Off".
2. Disconnect the MAF sensor connector and ECM
main relay.
3. Check the circuit for open circuit.
Was the problem found?


X-13E-63





-
Repair faulty
harness and
verify repair
Go to Step 8
8
Substitute a known good MAF & IAT sensor assembly
and recheck.
Was the problem solved?
- Go to Step 9 Go to Step 10
9
Replace the MAF & IAT sensor assembly.
Is the action complete?
- Verify repair -
10
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 11

3.5L ENGINE DRIVEABILITY AND EMISSIONS 6E-155
CIRCUIT DESCRIPTION
The mass air flow (MAF) sensor measures the amount
of air which passes through it into the engine during a
given time. The Engine Control Module (ECM) uses the
mass air flow information to monitor engine operating
conditions for fuel delivery calculations. A large quantity
of air entering the engine indicates an acceleration o
r
high load situation, while a small quantity of air indicates
deceleration or idle.
The MAF sensor produces a frequency signal which
can be monitored using a Tech 2. The frequency will
vary within a range of around 5

8 g/s at idle to around
25 to 40 g/s at maximum engine load. DTC P0103 will
be set if the signal from the MAF sensor is above the
possible range of a normally operating MAF sensor.

DIAGNOSTIC AIDS
If DTC P0103 cannot be duplicated, the information
included in the Failure Records data can be useful in
determining vehicle mileage since the DTC was last set.


Diagnostic Trouble Code (DTC) P0103 (Flash Code 61)
Mass Air Flow Sensor Circuit High Input
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 P0103 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 P0103 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 MAF sensor or
ECM connector. If a poor/faulty connection is found,
repair as necessary.
Was the problem found?


 E-61(B)
E-63






- Verify repair Go to Step 5

6E-156 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Step Action Value (s) Yes No
5
Remove the MAF & IAT sensor assembly and visually
check.
Was the problem found?
- Go to Step 9 Go to Step 6
6

Using the DVM and check the MAF sensor ground
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 MAF sensor connector.
4. Check the circuit for open circuit.
Was the problem found?

B39
Breaker BoxE-63






Breaker box is not available:
1. Ignition "Off", engine "Off".
2. Disconnect the MAF sensor connector and ECM
connector.
3. Check the circuit for open circuit.
Was the problem found?
E-63 E-61(B)







-

Repair faulty
harness and
verify repair

Go to Step 7