2004 ISUZU TF SERIES lock

6E–162 ENGINE DRIVEABILITY AND EMISSIONS
10 Check for the following conditions.
Objects blocking the 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 11
11 Check for injector for the affected bank.
Refer to “Injector Coil Test & Injector Balance Test
Procedure” 6E-98 page.
Was the injector operation correct?
—Go to Step 12Refer to Injector
Coil Test &
Injector
Balance Test
Procedure
12 Check for fuel pressure.
Refer to “Fuel System Diagnosis” 6E-108 page.
Was the fuel pressure correct? —Go to Step 13Refer to Fuel
System
Diagnosis
13 Replace the O
2 sensor.
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.—Veri fy repai r— Step A ction Value(s) Yes No

6E–164 ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Aids
Check for the following conditions:
Poor connection at ECM - Inspect harness
connectors for backed-out terminals, improper
mating, broken locks, improperly formed or damagedterminals, and poor terminal-to-wire connection.
Damaged harness - Inspect the wiring harness for
damage; shorts to ground, shorts to battery positive
and open circuits.
Diagnostic Trouble Code (DTC) P0135
O
2 Sensor Heater Circuit (Bank 1 Sensor 1)
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 P0135 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 P0135 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 O
2 sensor or
ECM connector. If a poor/faulty connection is found,
repair as necessary.
Was the problem found?
—Verify repair Go to Step 5
5 Visually check the O
2 sensor.
Was the problem found? —Go to Step 11Go to Step 6
6 Using the DVM and check the O
2 sensor.
1. Ignition “Off”, engine “Off”.
2. Disconnect O
2 sensor connector
3. Measure the resistance of heater.
Was the tester indicated specified value?
Approx imately
12.5
at 20°CGo to Step 7Go to Step 11
3431
C56(J2) E77
3 4
1234
O2 Sensor

ENGINE DRIVEABILITY AND EMISSIONS 6E–177
DIAGNOSTIC TROUBLE CODE (DTC) P0327 KNOCK SENSOR (KS) CIRCUIT
Condition for setting the DTC and action taken when the DTC sets
Circuit Description
The ECM uses the Knock Sensor (KS) in order to detect
engine detonation. This allows the ECM to retard the
Ignition Control (IC) spark timing based on the KS signal
the ECM receives. The knock sensors produce an AC
signal that rides on the 1.3 volts DC. The signal’s
amplitude and frequency are dependent upon the
amount of the knock being ex perienced.
The ECM determines whether the knock is occurring by
comparing the signal level on the KS circuit with a
voltage level on the noise channel. The normal engine
noise varies depending on the engine speed and load.
Then the ECM determines that an abnormally high
noise channel voltage level is being ex perienced, a
Diagnostic Trouble Code P0327 sets.
Diagnostic Aids
Check for the following conditions:
A poor connection at the ECM. Inspect the knock
sensor and the ECM connectors for: , broken locks,
improperly formed or damaged terminals.
Backed out terminals
Broken locks
Improperly formed or damaged terminals
Also, check the wiring harness for: shorts to ground,
shorts to battery positive, and open circuits.
A misrouted harness. Inspect the knock sensor
harness in order to ensure that it is not routed too
close to high voltage wires such as spark plug leads.
Code Type DTC Name DTC Setting Condition Fail-Safe (Back Up)
P0327 A Knock Se nsor Circuit 1. No DTC re lating to MAP senso r.
2. Engine coolant temperature is more than
50 de g. C.
3. Engine speed is more than 1600rpm.
4. Knock sensor harness short to ground or
short to vo lta ge circuit.ECM re ta rds ignitio n timing 4 deg. C.

ENGINE DRIVEABILITY AND EMISSIONS 6E–181
Diagnostic Aids
An intermittent may be caused by a poor connection,
rubbed-through wire insulation or a wire broken inside
the insulation. Check for:
Poor connection - Inspect the ECM harness and
connectors for improper mating, broken locks,
improperly formed or damaged terminals, and poor
terminal-to-wire connection.Damaged harness - Inspect the wiring harness for
damage; shorts to ground, shorts to battery positive
and open circuits. If the harness appears to be OK,
disconnect the ECM, turn the ignition on and observe
a voltmeter connected to the 58X reference circuit at
the ECM harness connector while moving connectors
and wiring harnesses related to the ECM. A change
in voltage will indicate the location of the fault.
Diagnostic Trouble Code (DTC) P0336
Crankshaft Position Sensor Circuit Range/performance (58x)
Diagnostic Trouble Code (DTC) P0337
Crankshaft Position Sensor Circuit Low Input (58x)
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 P0336 or P0337 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 P0336 or P0337 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 CKP sensor or
ECM connector. If a poor/faulty connection is found,
repair the faulty terminal.
Was the problem found?
—Verify repair Go to Step 5
5 Visually check the CKP sensor. If a faulty installation
is found, repair as necessary.
Was the problem found? —Verify repair Go to Step 6
21
61 E-60(J1) E-59

ENGINE DRIVEABILITY AND EMISSIONS 6E–187
mating, broken locks, improperly formed or damaged
terminals, and poor terminal-to-wire connections.
Damaged harness - Inspect the wiring harness for
damage; Open circuits, shorts to ground, or shorts to
Voltage. If the harness appears to be OK, observethe Tech 2 display related to DTC P0351 or P0352
while moving the connector and wiring related to the
ignition system. A change in the display will indicate
the location of the fault.
Diagnostic Trouble Code (DTC) P0351 Ignition 1 Control Circuit
Diagnostic Trouble Code (DTC) P0352 Ignition 2 Control Circuit
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 P0351 or P0352 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 P0351 or P0352 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 ignition coil
module or ECM connector. If a poor/faulty connection
is found, repair as necessary.
Was the problem found?
—Verify repair Go to Step 5
5 Visually check the ignition coil module.
Was the problem found?—Go to Step 12Go to Step 6
19 18
E-60(J1) E-18

ENGINE DRIVEABILITY AND EMISSIONS 6E–195
DIAGNOSTIC TROUBLE CODE (DTC) P0502 VEHICLE SPEED SENSOR (VSS)
CIRCUIT LOW INPUT
Condition for setting the DTC and action taken when the DTC sets
Circuit Description
The vehicle speed sensor has a magnet rotated by the
transmission output shaft. Attached to the sensor is a
hall effect circuit that interacts with the magnetic field
created by the rotating magnet. A 12-volt operating
supply for the speed sensor hall circuit is supplied from
the meter fuse.
Diagnostic Aids
Poor connection at ECM: Inspect harness connectors
for backed out terminals, improper mating, broken
locks, improperly formed or damaged terminals, and
poor terminal to wire connection.
Code Type DTC Name DTC Setting Condition Fail-Safe (Back Up)
P0502 B Vehicle Speed Sensor Circuit Low
Input1. No DTC relating to MAP senso r, TPS, ECT
se nsor, inje ctor co ntrol circuit a nd ignitio n
co ntro l circuit.
2. Engine is running.
3. Vehicle spe ed is below 3km/h in po wer
condition or 2km/h in deceleration condi-
tion.ECM use s 0km/h co ndition a s substitute.

6E–208 ENGINE DRIVEABILITY AND EMISSIONS
DTC P0650 MALFUNCTION INDICATOR LAMP (MIL) CONTOROL CIRCUIT
MALFUNCTION
Condition for setting the DTC and action taken when the DTC sets
Circuit Description
The check engine lamp should always be illuminated
and steady with ignition “ON” and the engine stopped.
Ignition feed voltage is supplied directly to the check
engine lamp indicator. The Engine Control Module
(ECM) turns the check engine lamp “ON” by grounding
the check engine lamp driver circuit. The check engine
lamp should not remain “ON” with the engine running
and no DTC(s) set. A steady check engine lamp with
the engine running and no DTC(s) suggests a short to
ground in the check engine lamp driver circuit.
Diagnostic Aids
An intermittent may be caused by a poor connection,
rubbed-through wire insulation, or a wire broken inside
the insulation. Check for the following items:
Poor connection or damaged harness - Inspect the
ECM harness and connectors for improper mating,
broken locks, improperly formed or damaged
terminals, poor terminal-to-wire connection, and
damaged harness.
Code Type DTC Name DTC Setting Condition Fail-Safe (Back Up)
P0650 A Malfunctio n Indicator La mp (MIL) Co n-
tro l Circuit Malfunctio nCheck engine lamp circuit open, short to
ground or short to voltage circuit.No fail-safe function.

6E–212 ENGINE DRIVEABILITY AND EMISSIONS
Perform “I njector Balance Test” - Refer to Fuel
System Diagnosis.
Check the EVAP canister for fuel saturation - If full of
fuel, check canister control and hoses. Refer to
Evaporative (EVAP) Emission Control System.
Check for a leak in the fuel pressure regulator
diaphragm by checking the vacuum line to toe
regulator for the presence of fuel.An intermittent TP sensor output will cause the
system to go rich due to a false indication of the
engine accelerating.
Silicon contamination of the HO2S can also cause a
high HO2S voltage to be indicated. This condition is
indicated by a powdery white deposit on the portion
of the HO2S ex posed to the ex haust stream. If
contamination is noticed, replace the affected HO2S.
Diagnostic Trouble Code (DTC) P1167
Fuel Supply Sy stem Rich During Deceleration Fuel Cutoff
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 P1167 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 P1167 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 “Off”.
2. Monitor the “Throttle Position” in the data display.
Does the Tech 2 indicate correct “Throttle Position” in
accordance with accelerator pedal operation? —Go to Step 6Go to Step 5
5 Check for the following conditions.
Objects blocking the throttle valve.
Incorrectly installed.
If a problem is found, repair as necessary.
Was the problem found?—Verify repair Go to Step 12
6 1. Using the Tech 2, ignition “On” and engine “On”.
2. Monitor the “Manifold Absolute Pressure” in the
data display.
Does the Tech 2 indicate correct “Manifold Absolute
Pressure” in accordance with engine speed or
acceleration? —Go to Step 8Go to Step 7
7 Remove the MAP sensor and check for the following
conditions.
Objects blocking the air cleaner.
Objects blocking the MAP 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 13