check engine ISUZU TF SERIES 2004 Workshop Manual

6E–196 ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0502 Vehicle Speed Sensor Circuit Low Input
Step A ction Value(s) Yes No
1 Was the “On-Board Diagnostic (OBD) System Check”
performed?
—Go to Step 2Go 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 P0502 stored as “Present Failure”?—Go to Step 3Refer 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 P0502 stored in this ignition cycle?—Go to Step 4Refer to
Diagnostic Aids
and Go to Step
4
4 Check for poor/faulty connection at the VSS, meter,
immobilizer control unit (if equipped), ECM and other
connectors. If a poor/faulty connection is found, repair
the faulty terminal.
Was the problem found?
—Verify repair Go to Step 5
5 Remove the VSS from the housing case and visually
check.
Was the problem found? —Go to Step 19Go to Step 6
68
23
27
910 C-56(J2)
B-68
B-24
E-44

ENGINE DRIVEABILITY AND EMISSIONS 6E–197
6 Using the DVM and check the VSS signal.
1. Ignition “On”, vehicle “Run (lift up)”.
2. Measure the VSS output voltage at sensor, meter,
immobilizer control unit (if equipped) and ECM.
Does the tester indicate specified value?
If a oscilloscope is available, monitor the VSS signal.
Does the oscilloscope indicate correct wave form?
Refer to
Diagnostic Aids
and Go to Step
21Refer the table
7 Using the DVM and check the VSS power supply
circuit.
1. Ignition “On”, engine “Off”.
2. Disconnect the VSS connector.
3. Check the circuit for open or short to ground
circuit.
Was the DVM indicated specified value?
10 - 14.5V Go to Step 9Go to Step 8
8 Repair the open circuit between the VSS and meter
fuse.
Is the action complete?—Veri fy repai r— Step A ction Value(s) Yes No
Me asure ment Position Vo lta ge (V)
(AC Range)If No
Go od
VSS terminal 3 & GND Appro xima te ly
7.0 V at 20km/hGo to
Step 7
Meter B24 connector 9 &
GNDGo to
Step 11
Meter B24 connector 10 &
GNDGo to
St e p 1 3
Immo bilize r control unit B68
co nnecto r 6 & GNDGo to
St e p 1 4
Immo bilize r control unit B68
co nnecto r 8 & GNDApproximately
6.5V at 20km/hGo to
St e p 1 6
ECM C56 (J2) co nnecto r 23 &
GNDGo to
St e p 1 7
Vehicle Speed Sensor (V SS) Reference Wave Form








CH1
0V


CH2
0V




Measurement Terminal: CH1: ECM J2-23(+) / CH2: VSS 3(+)
GND(-)
Measurement Scale: CH1: 10V/div / CH2: 10V/div 50ms/div
Measurement Condition: A pproxim ately 20km/h
Note: The vehicle is without immobilizer syste m,
CH1 signal is sam e as CH2.
V
E-44
1

6E–198 ENGINE DRIVEABILITY AND EMISSIONS
9 Using the DVM and check the VSS ground circuit.
1. Ignition “On”, engine “Off”.
2. Disconnect the VSS connector.
3. Check the circuit for short to power supply circuit.
Was the DVM indicated specified value?
Less than 1V Go to Step 10Repair faulty
harness and
verify repair
10 Using the DVM and check the VSS ground circuit.
1. Ignition “Off”, engine “Off”.
2. Disconnect the VSS connector.
3. Check the circuit for open circuit.
Was the problem found?
—Repair faulty
harness and
verify repair Go to Step 19
11 Using the DVM and check the VSS signal circuit.
1. Ignition “On”, engine “Off”.
2. Disconnect the VSS connector and meter
connector.
3. Check the circuit for short to power supply circuit.
Was the DVM indicated specified value?
Less than 1V Go to Step 12Repair faulty
harness and
verify repair Step A ction Value(s) Yes No
V
E-44
2
E-44
2
V
B-24
9

ENGINE DRIVEABILITY AND EMISSIONS 6E–199
12 Using the DVM and check the VSS signal circuit.
1. Ignition “Off”, engine “Off”.
2. Disconnect the VSS connector and meter
connector.
3. Check the circuit for open or short to ground
circuit.
If a open or short to ground circuit is found, repair the
faulty harness and verify repair.
Is the action complete?
—Veri fy repai r—
13 Replace the speed meter.
Is the action complete?—Veri fy repai r—
14 Using the DVM and check the VSS signal circuit.
1. Ignition “On”, engine “Off”.
2. Disconnect the meter connector and immobilizer
control unit connector (if equipped).
3. Check the circuit for short to power supply circuit.
Was the DVM indicated specified value?
Less than 1V Go to Step 15Repair faulty
harness and
verify repair
15 Using the DVM and check the VSS signal circuit.
1. Ignition “Off”, engine “Off”.
2. Disconnect the meter connector and immobilizer
control unit connector (if equipped).
3. Check the circuit for open or short to ground
circuit.
If a open or short to ground circuit is found, repair the
faulty harness and verify repair.
Is the action complete?
—Veri fy repai r— Step A ction Value(s) Yes No
B-24
9E-44
3
V
B-68
6
B-24
10B-68
6

6E–200 ENGINE DRIVEABILITY AND EMISSIONS
16 Replace the immobilizer control unit (if equipped).
Is the action complete?—Veri fy repai r—
17 Using the DVM and check the VSS signal circuit.
1. Ignition “Off”, engine “Off”.
2. Disconnect the immobilizer control unit connector
(if equipped) and ECM connector.
3. Ignition “On”.
4. Check the circuit for short to power supply circuit.
Was the DVM indicated specified value?
Less than 1V Go to Step 18Repair faulty
harness and
verify repair
18 Using the DVM and check the VSS signal circuit.
Breaker box is available:
1. Ignition “Off”, engine “Off”.
2. Install the breaker box as type A. (ECM
disconnected) Refer to 6E-88 page.
3. Disconnect the immobilizer control unit connector
(if equipped).
4. Check the circuit for open or shot to ground circuit.
Was the problem found?
Breaker box is not available:
1. Ignition “Off”, engine “Off”.
2. Disconnect the immobilizer control unit connector
(if equipped) and ECM connector.
3. Check the circuit for open or short to ground
circuit.
Was the problem found?
—Repair faulty
harness and
verify repair Go to Step 21
19 Substitute a known good VSS and recheck.
Was the problem solved?—Go to Step 20Go to Step 21 Step A ction Value(s) Yes No
V
C-56(J2)
23
J2-32Breaker BoxB-68




B-68 C-56(J2)
23
8

6E–202 ENGINE DRIVEABILITY AND EMISSIONS
DIAGNOSTIC TROUBLE CODE (DTC) P0562 SYSTEM VOLTAGE LOW
Condition for setting the DTC and action taken when the DTC sets
Circuit Description
The engine control module (ECM) monitors the system
voltage on the ignition feed terminal to the ECM. A
system voltage Diagnostic Trouble Code will set
whenever the voltage is below a calibrated value.
Diagnostic Aids
If the Diagnostic Trouble Code sets when an
accessory is operated, check for a poor connection or
excessive current draw.
Check for open circuits or shorts to ground on the
ECM’s battery or ignition inputs.
Diagnostic Trouble Code (DTC) P0562 System Voltage Low
Code Type DTC Name DTC Setting Condition Fail-Safe (Back Up)
P0562 D System Voltage Low Battery voltage is below 11V. No fail-safe function.
Step A ction Value(s) Yes No
1 Was the “On-Board Diagnostic (OBD) System Check”
performed?
—Go to Step 2Go to On Board
Diagnostic
(OBD) System
Check

ENGINE DRIVEABILITY AND EMISSIONS 6E–203
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 P0562 stored as “Present Failure”?—Go to Step 3Refer 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 P0562 stored in this ignition cycle?—Go to Step 4Refer to
Diagnostic Aids
and Go to Step
4
4 1. Using the Tech 2, ignition “On” and engine “On”.
2. Monitor the “Ignition Voltage” in the data display.
3. Load the electrical system by turning on the
headlights, etc..
Does the Tech 2 indicate enough ignition voltage? 10 - 14.5V Go to Step 6Go to Step 5
5 Using the DVM and check the battery voltage at the
battery terminal.
Does the tester indicate enough battery voltage?
10 - 14.5V Go to Step 6Check the
charging
system, charge
or replace the
battery
6 Check for poor/faulty connection at the ECM
connector. If a poor/faulty connection is found, repair
as necessary.
Was the problem found?
—Verify repair Go to Step 7
7 Check for poor/faulty connection of the ECM ground
at the inlet manifold. If a poor/faulty connection is
found, repair as necessary.
Was the problem found?
—Verify repair Go to Step 8
8 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 9
9 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.—Veri fy repai r— Step A ction Value(s) Yes No
16
2
17
12 C-56(J2)E-60(J1)
E-72

6E–204 ENGINE DRIVEABILITY AND EMISSIONS
DIAGNOSTIC TROUBLE CODE (DTC) P0563 SYSTEM VOLTAGE HIGH
Condition for setting the DTC and action taken when the DTC sets
Circuit Description
The engine control module (ECM) monitors the system
voltage on the ignition feed terminals to the ECM. A
system voltage Diagnostic Trouble Code will setwhenever the voltage is above a calibrated value.Diagnostic Aids
Check for a faulty charging system components.
Diagnostic Trouble Code (DTC) P0563 Sy stem Voltage High
Code Type DTC Name DTC Setting Condition Fail-Safe (Back Up)
P0563 A System Voltage High Battery voltage is above 16V. No fail-safe function.
Step A ction Value(s) Yes No
1 Was the “On-Board Diagnostic (OBD) System Check”
performed?
—Go to Step 2Go to On Board
Diagnostic
(OBD) System
Check

ENGINE DRIVEABILITY AND EMISSIONS 6E–205
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 P0563 stored as “Present Failure”?—Go to Step 3Refer 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 P0563 stored in this ignition cycle?—Go to Step 4Refer to
Diagnostic Aids
and Go to Step
4
4 1. Using the Tech 2, ignition “On” and engine “On”.
2. Monitor the “Ignition Voltage” in the data display.
3. Load the electrical system by turning on the
headlights, etc..
Does the Tech 2 indicate correct ignition voltage? Less than 16V Go to Step 5Check the
charging
system and Go
to Step 5
5 Is the battery jamp start cable incorrectly connecting?
—Verify
procedure Go to Step 6
6 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 7
7 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.—Veri fy repai r— Step A ction Value(s) Yes No

6E–206 ENGINE DRIVEABILITY AND EMISSIONS
DIAGNOSTIC TROUBLE CODE (DTC) P0601 ECM MEMORY CHECKSUM
Condition for setting the DTC and action taken when the DTC sets
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 powertrain diagnostics operation.
Unlike the PROM used in past applications, the
EEPROM is not replaceable. When the ECM is
replaced or a calibration update is required, the ECMmust be programmed using a Tech 2.Diagnostic Aids
Diagnostic Trouble Code P0601 indicates that the
contents of the EEPROM have changed since the
ECM was programmed. The only possible repair is
ECM reprogramming or replacement. Check service
bulletins to program the replacement ECM with the
correct software and calibration for the vehicle.
Diagnostic Trouble Code (DTC) P0601 ECM Memory Checksum
Code Type DTC Name DTC Setting Condition Fail-Safe (Back Up)
P0601 A ECM Me mo ry Che cksum ECM memo ry are a erro r. Engine co ntrol disabled.
Step A ction Value(s) Yes No
1 Was the “On-Board Diagnostic (OBD) System Check”
performed?
—Go to Step 2Go 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 3Refer 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 4Refer 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
5 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.—Veri fy repai r—