2004 ISUZU TF SERIES ECU

6E–2 ENGINE DRIVEABILITY AND EMISSIONS
5e. Vehicle Operates as Designed ............ 6E-65
6. Re-examine the complaint ..................... 6E-66
7. Repair and Verify Fix ............................. 6E-66
GENERAL SERVICE INFORMATION .......... 6E-67
On-Board Diagnostic (OBD) ...................... 6E-68
On-Board Diagnostic Tests ....................... 6E-68
The Diagnostic Executive .......................... 6E-68
Diagnostic Information ............................... 6E-68
Check Engine Lamp .................................. 6E-68
Data Link Connector (DLC) ....................... 6E-68
Tech 2 Operating Flow Cart (Start Up) ...... 6E-70
TYPICAL SCAN DATA & DEFINITIONS
(ENGINE DATA) ......................................... 6E-72
TYPICAL SCAN DATA & DEFINITIONS
(O2 SENSOR DATA) .................................. 6E-74
MISCELLANEOUS TEST ............................. 6E-76
PLOTTING SNAPSHOT GRAPH ................. 6E-78
Plotting Graph Flow Chart (Plotting graph after
obtaining vehicle information) .................. 6E-79
Flow Chart for Snapshot Replay
(Plotting Graph) ....................................... 6E-80
SNAPSHOT DISPLAY WITH TIS2000 ......... 6E-81
ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK
6E-98
Circuit Description ......................................... 6E-90
Diagnostic Aids ............................................. 6E-90
Test Description ............................................ 6E-90
ON-BOARD DIAGNOSTIC (OBD) SYSTEM
CHECK .................................................... 6E-91
NO CHECK ENGINE LAMP (MIL) ................ 6E-94
Circuit Description ..................................... 6E-94
Diagnostic Aids .......................................... 6E-94
No Check Engine Lamp (MIL) ................... 6E-94
CHECK ENGINE LAMP (MIL) “ON” STEADY 6E-96
Circuit description ...................................... 6E-96
Diagnostic Aids .......................................... 6E-96
Check Engine Lamp (MIL) “ON” Steady .... 6E-96
FUEL METERING SYSTEM CHECK ........... 6E-98
FUEL INJECTOR COIL TEST PROCEDURE
AND FUEL INJECTOR BALANCE TEST
PROCEDURE ............................................. 6E-98
Test Description ......................................... 6E-98
Injector Coil Test Procedure (Steps 1-6)
and Injector Balance Test Procedure
(Steps 7-11) ............................................. 6E-99
Injector Coil Test Procedure (Steps 1-6)
and Injector Balance Test Procedure
(Steps 7-11) ............................................. 6E-100
FUEL SYSTEM ELECTRICAL TEST ........... 6E-103
Circuit Description ..................................... 6E-103
Diagnostic Aids .......................................... 6E-104Fuel Pressure Relief Procedure ................. 6E-104
Fuel Pressure Gauge Installation .............. 6E-104
Fuel System Electrical Test ....................... 6E-104
FUEL SYSTEM DIAGNOSIS ........................ 6E-108
Circuit Description ...................................... 6E-108
Test Description ......................................... 6E-108
Fuel Pressure Relief Procedure ................. 6E-109
Fuel Pressure Gauge Installation .............. 6E-109
Fuel System Diagnosis .............................. 6E-110
ECM DIAGNOSTIC TROUBLE CODES (DTC) 6E-113
DIAGNOSTIC TROUBLE CODE (DTC) P0107
MANIFOLD ABSOLUTE PRESSURE
CIRCUIT LOW INPUT ................................ 6E-119
Circuit Description ...................................... 6E-119
Diagnostic Aids .......................................... 6E-119
Diagnostic Trouble Code (DTC) P0107
Manifold Absolute Pressure Circuit Low
Input ......................................................... 6E-120
DIAGNOSTIC TROUBLE CODE (DTC) P0108
MANIFOLD ABSOLUTE PRESSURE
CIRCUIT HIGH INPUT ............................... 6E-123
Circuit Description ...................................... 6E-123
Diagnostic Aids .......................................... 6E-124
Diagnostic Trouble Code (DTC) P0108
Manifold Absolute Pressure Circuit High
Input ......................................................... 6E-124
DIAGNOSTIC TROUBLE CODE (DTC) P0112
INTAKE AIR TEMPERATURE SENSOR LOW
INPUT ......................................................... 6E-127
Circuit Description ...................................... 6E-127
Diagnostic Aids .......................................... 6E-127
Diagnostic Trouble Code (DTC) P0112
Intake Air Temperature Sensor Low Input 6E-128
DIAGNOSTIC TROUBLE CODE (DTC) P0113
INTAKE AIR TEMPERATURE SENSOR HIGH
INPUT ......................................................... 6E-131
Circuit Description ...................................... 6E-131
Diagnostic Aids .......................................... 6E-131
Diagnostic Trouble Code (DTC) P0113
Intake Air Temperature Sensor High Input 6E-132
DIAGNOSTIC TROUBLE CODE (DTC) P0117
ENGINE COOLANT TEMPERATURE
SENSOR LOW INPUT ................................ 6E-136
Circuit Description ...................................... 6E-136
Diagnostic Aids .......................................... 6E-136
Diagnostic Trouble Code (DTC) P0117
Engine Coolant Temperature Sensor Low
Input ......................................................... 6E-137
DIAGNOSTIC TROUBLE CODE (DTC) P0118
ENGINE COOLANT TEMPERATURE
SENSOR HIGH INPUT ............................... 6E-139
Circuit Description ...................................... 6E-139

6E–4 ENGINE DRIVEABILITY AND EMISSIONS
DIAGNOSTIC TROUBLE CODE (DTC) P0443
EVAPORATIVE (EVAP) EMISSION CONTROL
SYSTEM PURGE CONTROL CIRCUIT ..... 6E-191
Circuit Description ..................................... 6E-191
Diagnostic Aids .......................................... 6E-191
Diagnostic Trouble Code (DTC) P0443
EVAP Emission Control System Purge
Control Circuit .......................................... 6E-192
DIAGNOSTIC TROUBLE CODE (DTC) P0502
VEHICLE SPEED SENSOR (VSS) CIRCUIT
LOW INPUT ................................................ 6E-195
Circuit Description ..................................... 6E-195
Diagnostic Aids .......................................... 6E-195
Diagnostic Trouble Code (DTC) P0502
Vehicle Speed Sensor Circuit Low Input . 6E-196
DIAGNOSTIC TROUBLE CODE (DTC) P0562
SYSTEM VOLTAGE LOW .......................... 6E-202
Circuit Description ..................................... 6E-202
Diagnostic Aids .......................................... 6E-202
Diagnostic Trouble Code (DTC) P0562 System
Voltage Low ............................................. 6E-202
DIAGNOSTIC TROUBLE CODE (DTC) P0563
SYSTEM VOLTAGE HIGH ......................... 6E-204
Circuit Description ..................................... 6E-204
Diagnostic Aids .......................................... 6E-204
Diagnostic Trouble Code (DTC) P0563 System
Voltage High ............................................ 6E-204
DIAGNOSTIC TROUBLE CODE (DTC) P0601
ECM MEMORY CHECKSUM ..................... 6E-206
Circuit Description ..................................... 6E-206
Diagnostic Aids .......................................... 6E-206
Diagnostic Trouble Code (DTC) P0601 ECM
Memory Checksum .................................. 6E-206
DIAGNOSTIC TROUBLE CODE (DTC) P0602
ECU PROGRAMMING ERROR ................. 6E-207
Circuit Description ..................................... 6E-207
Diagnostic Aids .......................................... 6E-207
Diagnostic Trouble Code (DTC) P0602 ECU
Programming Error .................................. 6E-207
DTC P0650 MALFUNCTION INDICATOR LAMP
(MIL) CONTOROL CIRCUIT MALFUNCTION 6E-208
Circuit Description ..................................... 6E-208
Diagnostic Aids .......................................... 6E-208
Diagnostic Trouble Code (DTC) P0650
Malfunction Indicator Lamp (MIL) Control
Circuit Malfunction ................................... 6E-209
DIAGNOSTIC TROUBLE CODE (DTC) P1167
FUEL SUPPLY SYSTEM RICH DURING
DECELERATION FUEL CUT OFF ............. 6E-211
Circuit Description ..................................... 6E-211
Diagnostic Aids .......................................... 6E-211
Diagnostic Trouble Code (DTC) P1167 Fuel Supply System Rich During
Deceleration Fuel Cutoff .......................... 6E-212
DIAGNOSTIC TROUBLE CODE (DTC) P1171
FUEL SUPPLY SYSTEM LEAN DURING
POWER ENRICHMENT ............................. 6E-214
Circuit Description ...................................... 6E-214
Diagnostic Aids .......................................... 6E-215
Diagnostic Trouble Code (DTC) P1171
Fuel Supply System Lean During Power
Enrichment .............................................. 6E-215
DIAGNOSTIC TROUBLE CODE (DTC) P1625
ECM SYSTEM RESET ............................... 6E-217
Circuit Description ...................................... 6E-217
Diagnostic Aids .......................................... 6E-217
Diagnostic Trouble Code (DTC) P1625 ECM
System Reset .......................................... 6E-217
DIAGNOSTIC TROUBLE CODE (DTC) P1626
IMMOBILIZER NO SIGNAL ........................ 6E-218
Circuit Description ...................................... 6E-218
Diagnostic Aids .......................................... 6E-218
Diagnostic Trouble Code (DTC) P1626
Immobilizer No Signal .............................. 6E-219
DIAGNOSTIC TROUBLE CODE (DTC) P1631
IMMOBILIZER WRONG SIGNAL ............... 6E-222
Circuit Description ...................................... 6E-222
Diagnostic Aids .......................................... 6E-222
Diagnostic Trouble Code (DTC) P1631
Immobilizer Wrong Signal ........................ 6E-223
DIAGNOSTIC TROUBLE CODE (DTC) P1648
WRONG SECURITY CODE ENTERED .. 6E-224
Circuit Description ...................................... 6E-224
Diagnostic Aids .......................................... 6E-224
Diagnostic Trouble Code (DTC) P1648 Wrong
Security Code Entered ............................ 6E-225
DIAGNOSTIC TROUBLE CODE (DTC) P1649
IMMOBILIZER FUNCTION NOT
PROGRAMMED ......................................... 6E-226
Circuit Description ...................................... 6E-226
Diagnostic Aids .......................................... 6E-226
Diagnostic Trouble Code (DTC) P1649
Immobilizer Function Not Programmed ... 6E-227
DIAGNOSTIC TROUBLE CODE (DTC) P1693
TACHOMETER OUTPUT LOW VOLTAGE 6E-228
Circuit Description ...................................... 6E-228
Diagnostic Aids .......................................... 6E-228
Diagnostic Trouble Code (DTC) P1693
Tachometer Output Low Voltage ............. 6E-229
SYMPTOM DIAGNOSIS ............................... 6E-232
PRELIMINARY CHECKS ............................. 6E-232
VISUAL/PHYSICAL CHECK ......................... 6E-232
INTERMITTENT ........................................... 6E-232

6E–66 ENGINE DRIVEABILITY AND EMISSIONS
Vehicle service information (service manual, etc.)
ISUZU field support
Ex perience
Identical vehicle or system for comparison
6. Re-examine the complaint
When you do not successfully find/isolate the problem
after ex ecuting a diagnostic path, you should re-
ex amine the complaint.
What you should do
In this case, you will need to backtrack and review
information accumulated from step 1 through 4 of
Strategy Based Diagnostics. You also should repeat any
procedures that require additional attention.
A previous path may be eliminated from consideration
only if you are certain that all steps were ex ecuted as
directed. You must then select another diagnostic path
(step 5a, 5b, 5c or 5d). If all possible options have been
ex plored, you may call or seek ISUZU field support.
What resources you should use
Whenever possible, you should use the following
resources to facilitate the diagnostic process:
Service manual
Accumulated information form a previous diagnostic
path
Service information and publications
ISUZU field support
7. Repair and Verify Fix
What you should do
After you have located the cause of the problem, you
must ex ecute a repair by following recommended
service manual procedures.
When the repair is completed, you should verify the fix
by performing the system checks under the conditions
listed in the customer complaint.
If applicable, you should carry out preventive measures
to avoid a repeat complaint.
What resources you should use
Whenever possible, you should use the following
resources to facilitate the repair process:
Electrical repair procedures
Service manual information and publications

6E–68 ENGINE DRIVEABILITY AND EMISSIONS
On-Board Diagnostic (OBD)
On-Board Diagnostic Tests
A diagnostic test is a series of steps, the result of which
is a pass or fail reported to the diagnostic ex ecutive.
When a diagnostic test reports a pass result, the
diagnostic ex ecutive records the following data:
The diagnostic test has been completed since the
last ignition cycle.
The diagnostic test has passed during the current
ignition cycle.
The fault identified by the diagnostic test is not
currently active.
When a diagnostic test reports a fail result, the
diagnostic ex ecutive records the following data:
The diagnostic test has been completed since the
last ignition cycle.
The fault identified by the diagnostic test is currently
active.
The fault has been active during this ignition cycle.
The operating conditions at the time of the failure.
The Diagnostic Executive
The Diagnostic Executive is a unique segment of
software which is designed to coordinate and prioritize
the diagnostic procedures as well as define the protocol
for recording and displaying their results. The main
responsibilities of the Diagnostic Ex ecutive are listed as
follows:
Commanding the check engine lamp on and off
DTC logging and clearing
Current status information on each diagnostic
Diagnostic Information
The diagnostic charts and functional checks are
designed to locate a faulty circuit or component through
a process of logical decisions. The charts are prepared
with the requirement that the vehicle functioned
correctly at the time of assembly and that there are not
multiple faults present.
There is a continuous self-diagnosis on certain control
functions. This diagnostic capability is complemented
by the diagnostic procedures contained in this manual.
The language of communicating the source of the
malfunction is a system of diagnostic trouble codes.
When a malfunction is detected by the control module, a
diagnostic trouble code is set and the check engine
lamp is illumi nated.
Check Engine Lamp
The check engine lamp looks the same as the check
engine lamp you are already familiar with, the “Check
Engine” lamp.
Basically, the check engine lamp is turned on when the
ECM detects a DTC that will impact the vehicle
emissions.
When the check engine lamp remains “ON” while the
engine is running, or when a malfunction issuspected due to a driveability or emissions problem,
a Powertrain On-Board Diagnostic (OBD) System
Check must be performed. The procedures for these
checks are given in On-Board Diagnostic (OBD)
System Check. These checks will ex pose faults
which may not be detected if other diagnostics are
performed first.
Data Link Connector (DLC)
The provision for communication with the contorl
module is the Data Link Connector (DLC). It is located
behind the lower front instrument panel. The DLC is
used to connect to a Tech 2. Some common uses of the
Tech 2 are listed below:
Identifying stored Diagnostic Trouble Codes (DTCs).
Clearing DTCs.
Reading serial data.
Ver ify in g Veh icle Repair
Verification of vehicle repair will be more
comprehensive for vehicles with OBD system
diagnostic. Following a repair, the technician should
perform the following steps:
1. Review and record the Fail Records for the DTC
which has been diagnosed.
2. Clear DTC(s).
3. Operate the vehicle within conditions noted in the
Fail Records.
4. Monitor the DTC status information for the specific
DTC which has been diagnosed until the diagnostic
test associated with that DTC runs.
Following these steps is very important in verifying
repairs on OBD systems. Failure to follow these steps
could result in unnecessary repairs.

ENGINE DRIVEABILITY AND EMISSIONS 6E–81
SNAPSHOT DISPLAY WITH TIS2000
Procedures for transferring and displaying Tech2
snapshot data by using TIS2000 [Snapshot Upload]
function is described below.
Snapshot data can be displayed with [Snapshot Upload]
function included in TIS2000.
1. Record the snapshot data, in Tech2.
2. Transfer the snapshot data to PC.By analyzing these data in various methods, trouble
conditions can be checked.
Snapshot data is displayed by ex ecuting the three steps
below shown:
After recording the snapshot in Tech2, transfer the data
from Tech2 to PC by the below procedures.
1. Start TIS2000.
2. Select [Snapshot Upload] on the TIS2000 start
screen.
3. Select [Upload from trouble diagnosis tool (transfer
from diagnosis tester)] or click the corresponding
icon of the tool bar.
4. Select Tech2, and transfer the recorded snapshot
information. 5. Select the transferred snapshot.
6. After ending transfer of the snapshot, data
parameter list is displayed on the screen.

6E–86 ENGINE DRIVEABILITY AND EMISSIONS
5. After choosing the data, click the “Nex t” button.
6. When all the necessary information is entered, the
“details” of software within the database that match
the entered data will appear for confirmation. Click
the “Program” switch and then download the new
software onto Tech-2.
7.“Data Transfer” comes on display. The progress of
downloading will be displayed on the screen in the
form of bar graph.
8. Upon finishing the data transfer, turn off the power
of Tech-2, removing from P/C.4. Programming of ECM
1. Check to see if batteries are fully charged, while
ABS connectors shall be removed from the vehicle.
2. Connect Tech-2 to Vehicle Diagnostic Connectors.
3. Turn on the power of Tech-2 and the title screen
comes on display.
4. Turn on the ignition (without allowing the engine to
start)
5. On the title screen of Tech-2, push the “Enter”
button.
6. Choose “F1: Service Programming System” on the
main screen and then choose “Fl: Program ECU”.
7. While data is being transferred, “Programming in
Progress” will be displayed on the Tech-2 screen.
8. Upon finishing the data transfer, Tech-2 will display
“Reprogramming Was Successful”. Push the “Exit”
button to bring program to completion
9. Following “Procedure 2: Demand of Data”, try over
again “Information Obtaining” and check to confirm
if the data has been correctly re-loaded.
10. Upon finishing confirmation, turn off the ignition of
the vehicle and then turn off the power of Tech-2,
removing from the vehicle.

ENGINE DRIVEABILITY AND EMISSIONS 6E–11 3
ECM DIAGNOSTIC TROUBLE CODES (DTC)Type A
Emission related.
Requests illumination of the MIL (Malfunction Indicator Lamp = Check Engine Lamp) of the first trip with a fail.
Stores a history DTC on the first trip.
Stores a freeze frame (If empty).
Stores a fail record.
Updates the fail record each time the diagnostic test fails.
Type B
Emission related.
“Armed” after one trip with fail.
“Disarmed” after one trip with a pass.
Requests illumination of the MIL on the second consecutive trip with a fail.
Store a history DTC on the second consecutive trip with a fail. (The DTC will be armed after the first fail.)
Stores a freeze frame on the second consecutive trip with a fail (If empty).
Stores a fail record when the first test fails (not dependent on consecutive trip).
Updates the fail record each time the diagnostic test fails.
Type D
Non emission related.
Does not request illumination of any lamp.
Stores a history DTC on the first trip.
Does not store a freeze frame.
Stores fail record when test fails.
Updates the fail record each time the diagnostic test fails.

ENGINE DRIVEABILITY AND EMISSIONS 6E–115
P0122 A Throttle Position Sensor Low Input TPS output voltage is below 0.14V. The ECM uses 0% condition as
substitute.TPS output voltage is more than 0.14V. 1. Sensor power supply circuit open or short
to ground circuit.
2. Sensor signal circuit open or short to
ground circuit.
3. Poor connector connection.
4. TPS malfunction.
5. ECM malfunction.J1-7/
J1-15/
P0123 A Throttle Position Sensor High Input TPS output voltage is more than 4.9V. TPS output voltage is below 4.9V. 1. Sensor power supply circuit short to
voltage circuit.
2. Sensor signal circuit short to voltage
circuit.
3. Sensor ground circuit open or short to
voltage circuit.
4. Poor connector connection.
5. TPS malfunction.
6. ECM malfunction.J1-7/
J1-15/
J1-32
P0131 A O
2 Sensor Circuit Low Voltage (Bank 1
Sensor 1)1. No DTC relating to MAP sensor, TPS,
EVAP purge, ECT sensor, CKP sensor,
VSS, injector control circuit and ignition
control circuit.
2. Engine coolant temperature is more than
60 deg. C.
3. O
2 sensor bank 1 output voltage is below
50mV in “Closed Loop” condition. “Open Loop” fuel control. O
2 sensor bank 1 output voltage is more
than 50mV.1. Sensor harness short to ground circuit.
2. O
2 sensor malfunction.
3. ECM malfunction.J2-6/
J2-21
P0132 A O
2 Sensor Circuit High Voltage (Bank 1
Sensor 1)1. No DTC relating to MAP sensor, TPS,
EVAP purge, ECT sensor, CKP sensor,
VSS, injector control circuit and ignition
control circuit.
2. Engine coolant temperature is more than
60 deg. C.
3. O
2 sensor bank 1 output voltage is more
than 952mV in “Closed Loop” condition. O
2 sensor bank 1 output voltage is below
952mV.1. Sensor harness short to voltage circuit.
2. O
2 sensor malfunction.
3. MAF sensor output is incorrect.
4. Air intake line malfunction.
5. IAC valve malfunction.
6. Incorrect fuel pressure.
7. Injector malfunction.
8. ECM malfunction.J2-6/
J2-21
P0134 A O
2 Sensor Circuit No Activity Detected
(Bank 1 Sensor 1)1. No DTC relating to MAP sensor, TPS,
EVAP purge, ECT sensor, CKP sensor,
VSS, injector control circuit and ignition
control circuit.
2. Engine coolant temperature is more than
60 deg. C.
3. Engine run time is longer than 40
seconds.
4. Mass air flow is more than 7g/s.
5. O
2 sensor bank 1 output voltage is
between 300mV and 600mV.O
2 sensor bank 1 output voltage is below
3 0 0 m V c o n s e c u t i v e l y .
O R
O2 sensor bank 1 output voltage is more
than 600mV consecutively.1. Sensor harness open circuit.
2. O
2 sensor malfunction.
3. MAF sensor output is incorrect.
4. Air intake line malfunction.
5. IAC valve malfunction.
6. Incorrect fuel pressure.
7. Injector malfunction.
8. ECM malfunction.J2-6/
J2-21 Code Type DTC Name DTC Setting Condition Fail-Safe (Back Up) Recovery Condition Related Failure Parts Related
ECM
Pin No.