2004 ISUZU TF SERIES ignition

6E–104 ENGINE DRIVEABILITY AND EMISSIONS
Fuel Pressure Relief Procedure
1. Remove the fuel cap.
2. Remove the fuel pump relay from the underhood
relay center.
3. Start the engine and alow it to stall.
4. Crank the engine for an additional 3 seconds.
Fuel Pressure Gauge Installation
1. Remove the fuel pressure fitting cap.
2. Install fuel pressure gauge 5-8840-0378-0 to the
fuel feed line located in front of and above the right
side valve cover.
3. Reinstall the fuel pump relay.
Fuel System Electrical Test
Step Action Value(s) Yes No
1Was the “On-Board Diagnostic (OBD) System Check”
performed?
—Go to Step 2Go to On Board
Diagnostic
(OBD) System
Check
2 1. Using the Tech 2, ignition “On” and engine “On”.
2. Select the “Miscellaneous Test” and perform the
“Fuel Pump Relay” in the “Relays”.
3. Operate the Tech 2 in accordance with procedure.
Was the fuel pump operated, when the Tech 2 is
operated?—Go to Fuel
System
DiagnosisGo to Step 3
3 Check the “Fuel Pump” fuse (20A).
If the fuse is burnt out, repair as necessary.
Was the problem found?—Verify repair Go to Step 4
4 Check for poor/faulty connection at the fuel pump, fuel
pump relay or ECM connector. If a poor/faulty
connection is found, repair as necessary.
Was the problem found?
—Verify repair Go to Step 5
5 Using the DVM and check the fuel pump relay.
1. Ignition “Off”, engine “Off”.
2. Remove the fuel pump relay from the relay box .
3. Check the relay coil.
Was the DVM indicated specified value?
120 - 150
Go to Step 6Replace fuel
pump relay and
verify repair
11C56(J2)
F2 X2
Fuel Pump Relay

 




ENGINE DRIVEABILITY AND EMISSIONS 6E–105
6 Using the DVM and check the fuel pump relay power
supply circuit.
1. Ignition “On”, engine “Off”.
2. Remove the fuel pump relay from the relay box .
3. Check the circuit for open or short to ground
circuit.
Was the DVM indicated specified value?
10 - 14.5V Go to Step 8Go to Step 7
7 Repair the open or short to ground circuit between the
“ECM” fuse (15A) and fuel pump relay.
Is the action complete?—Veri fy repai r—
8 Using the DVM and check the fuel pump relay ground
circuit.
1. Ignition “Off”, engine “Off”.
2. Disconnect the ECM connector.
3. Remove the fuel pump relay from the relay box .
4. Check the circuit for open or short to ground
circuit.
Was the problem found?
—Repair faulty
harness and
verify repair Go to Step 9
9 Using the DVM and check the fuel pump relay power
supply circuit.
1. Ignition “Off”, engine “Off”.
2. Remove the fuel pump relay from the relay box .
3. Check the circuit for open circuit.
Was the DVM indicated specified value?
10 - 14.5V Go to Step 11Go to Step 10 Step Action Value(s) Yes No
V
3
X2
4
11C56(J2) X2
V
1X2

6E–106 ENGINE DRIVEABILITY AND EMISSIONS
10 Repair the open circuit between the fuel pump relay
and battery.
Is the action complete?—Veri fy repai r—
11 Using the DVM and check the fuel pump power supply
circuit.
1. Ignition “On”, engine “Off”.
2. Disconnect the fuel pump connector.
3. Check the circuit for open or short to ground
circuit.
Was the DVM indicated specified value?
10 - 14.5V Go to Step 13Go to Step 12
12 Repair the open or short to ground circuit between the
fuel pump relay and fuel pump.
Is the action complete?—Veri fy repai r—
13 Using the DVM and check the fuel pump ground
circuit.
1. Ignition “Off”, engine “Off”.
2. Disconnect the fuel pump connector.
3. Check the circuit for open circuit.
Was the DVM indicated specified value?
Continuity Go to Step 15Go to Step 14
14 Repair the open circuit between the fuel pump and
body ground.
Is the action complete?—Veri fy repai r—
15 Replace the fuel pump.
Was the problem solved?—Verify repair Go to Step 16
16 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 17 Step Action Value(s) Yes No
V
1
F2
F-2




6E–108 ENGINE DRIVEABILITY AND EMISSIONS
FUEL SYSTEM DIAGNOSIS
Circuit Description
When the ignition switch is turned ON, the engine
control module (ECM) will turn ON the in-tank fuel
pump. The in-tank fuel pump will remain ON as long as
the engine is cranking or running and the ECM is
receiving 58X crankshaft position pulses. If there are no
58X crankshaft position pulses, the ECM will turn the in-
tank fuel pump OFF 2 seconds after the ignition switch
is turned ON or 2 seconds after the engine stops
running.
The in-tank fuel pump is an electric pump within an
integral reservoir. The in-tank fuel pump supplies fuel
through an in-line fuel filter to the fuel rail assembly. The
fuel pump is designed to provide fuel at a pressure
above the pressure needed by the fuel injectors. A fuel
pressure regulator, attached to the fuel rail, keeps the
fuel available to the fuel injectors at a regulated
pressure. Unused fuel is returned to the fuel tank by a
separate fuel return line.
Test Description
Number(s) below refer to the step number(s) on the
Diagnostic Chart.
2. Connect the fuel pressure gauge to the fuel feed line
as shown in the fuel system illustration. Wrap a shop
towel around the fuel pressure connection in order to
absorb any duel leakage that may occur when
installing the fuel pressure gauge. With the ignition
switch ON and the fuel pump running, the fuel
pressure indicated by the fuel pressure gauge
should be 283-376 kPa (41-55 psi). This pressure is
controlled by the amount of pressure the spring
inside the fuel pressure regulator can provide.
3. A fuel system that cannot maintain a constant fuel
pressure has a leak in one or more of the following
areas:
The fuel pump check valve.
The fuel pump flex line.
The valve or valve seat within the fuel pressure
regulator.

6E–110 ENGINE DRIVEABILITY AND EMISSIONS
Fuel System Diagnosis
Step Action Value(s) Yes No
1Was the “On-Board Diagnostic (OBD) System Check”
performed?—Go to Step 2Go to OBD
System Check
2 1. Turn the ignition OFF.
2. Turn the air conditioning system OFF.
3. Relieve fuel system pressure and install the fuel
pressure gauge.
4. Turn the ignition ON.
NOTE: The fuel pump will run for approx imately 2
seconds. Use the Scan Tool to command the fuel
pump ON.
5. Observe the fuel pressure indicated by the fuel
pressure gauge with the fuel pump running.
Is the fuel pressure within the specified limits?283-376 kPa
(41-55 psi) Go to Step 3Go to Step 17
3 Does the fuel pressure indicated by the fuel pressure
gauge remain constant?
NOTE: The fuel pressure will drop when the fuel
pump stops running, then it should stabilize and
remain constant.—Go to Step 4Go to Step 12
4 1. When the vehicle is at normal operating
temperature, turn the ignition ON to build fuel
pressure and observe the measurement on the
gauge.
2. Start the engine and observe the fuel pressure
gauge.
Did the reading drop by the amount specified after the
engine was started?21-105 kPa
(3-15 psi) Go to Step 5Go to Step 9
5 Is fuel pressure dropping off during acceleration,
cruise, or hard cornering?—Go to Step 6Check for
improper fuel
6 Visually and physically inspect the following items for
a restriction:
The in-line fuel filter.
The fuel feed line.
Was a restriction found?—Verify repair Go to Step 7
7 Remove the fuel tank and visually and physically
inspect the following items:
The fuel pump strainer for a restriction.
The fuel line for a leak.
Verify that the correct fuel pump is in the vehicle.
Was a problem found in any of these areas?—Verify repair Go to Step 8
8 Replace the fuel pump.
Is the action complete?—Veri fy repai r—
9 1. Disconnect the vacuum hose from the fuel
pressure regulator.
2. With the engine idling, apply 12-14 inches of
vacuum to the fuel pressure regulator.
Does the fuel pressure indicated by the fuel pressure
gauge drop by the amount specified?21-105 kPa
(3-15 psi) Go to Step 10Go to Step 11

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.

6E–116 ENGINE DRIVEABILITY AND EMISSIONSP0135 A O
2 Sensor Heater Circuit (Bank 1 Sensor
1)1. No DTC relating to MAP sensor and ECT
sensor.
2. Engine coolant temperature is more than
60 deg. C.
3. Engine run time is longer than 20
seconds.
4. MAP sensor output is more than 70kPa.
5. O
2 sensor bank 1 heater current more
than 10mA.No fail-safe function. O
2 sensor bank 1 heater circuit is correct
condition.1. Heater harness open, short to ground or
short to voltage circuit.
2. O
2 sensor heater malfunction.
3. ECM malfunction.J2-31
P0201 A Injector 1 Control Circuit 1. Engine is running.
2. Engine speed is more than 1000rpm.
3. Injector voltage does not meet to the
battery voltage when the injector is
commanded Off or does not meet to the
0V when the injector is commanded On.Injector circuit is correct condition. 1. Injector harness open circuit, short to
ground or short to voltage circuit.
2. Injector malfunction.
3. ECM malfunction.J1-9
P0202 A Injector 2 Control CircuitJ1-22
P0203 A Injector 3 Control CircuitJ1-8
P0204 A Injector 4 Control CircuitJ1-11
P0325 B Knock Sensor Module Circuit 1. No DTC relating to MAP sensor.
2. Engine coolant temperature is more than
50 deg. C.
3. Engine speed is more than 1600rpm.
4. Knock sensor filter module integrated
circuit malfunction.ECM retards ignition timing 4 deg.
C.Knock sensor is correct condition. 1. KS harness open circuit.
2. Poor connector connection.
3. KS sensor malfunction.
4. ECM malfunction.J1-3/
J1-32
P0327 A Knock Sensor Circuit 1. No DTC relating to MAP sensor.
2. Engine coolant temperature is more than
50 deg. C.
3. Engine speed is more than 1600rpm.
4. Knock sensor harness short to ground or
short to voltage circuit.1. KS harness short to ground or short to
voltage circuit.
2. Poor connector connection.
3. KS sensor malfunction.
4. ECM malfunction.J1-3/
J1-32
P0336 B Crankshaft Position Sensor Circuit Range/
Performance (58X)1. Engine is running.
2. Extra or missing pulse is detected
consecutively. No fail-safe function. Correct pulse is detected consecutively. 1. CKP sensor harness open circuit, short to
ground or short to voltage circuit.
2. Poor connector connection.
3. CKP sensor malfunction.
4. Pulse sensing gap incorrect.
5. Pluser malfunction.
6. Electrical interference.
7. Magnetic interference.
8. ECM malfunction.J1-6/
J1-21
P0337 B Crankshaft Position Sensor Circuit Low
Input (58X)No pulse is detected during engine cranking.1. CKP sensor harness open circuit, short to
ground or short to voltage.
2. Poor connector connection.
3. CKP sensor malfunction.
4. Pulse sensing gap incorrect.
5. Pluser malfunction.
6. Electrical interference.
7. Magnetic interference.
8. ECM malfunction.J1-6/
J1-21 Code Type DTC Name DTC Setting Condition Fail-Safe (Back Up) Recovery Condition Related Failure Parts Related
ECM
Pin No.

ENGINE DRIVEABILITY AND EMISSIONS 6E–117
P0351 A Ignition 1 Control Circuit #1 or #4cylinder ignition signals are not
detected consecutively.No fail-safe function. Consecutive ignition signals are detected. 1. Ignition coil module 1 harness open
circuit, short to ground or short to voltage
circuit.
2. Ignition coil module malfunction.
3. ECM malfunction.J1-19
P0352 A Ignition 2 Control Circuit #2 or #3 cylinder ignition signals are not
detected consecutively.1. Ignition coil module 2 harness open circuit,
short to ground or short to voltage circuit.
2. Ignition coil module malfunction.
3. ECM malfunction.J1-18
P0443 B EVAP Emission Control System Purge
Control CircuitEVAP purge solenoid circuit open, short to
ground or short to voltage circuit.No fail-safe function. EVAP purge solenoid circuit is correct
condition.1. Solenoid harness open circuit, short to
ground or short to voltage circuit.
2. Solenoid malfunction.
3. ECM malfunction.J1-5
P0502 B Vehicle Speed Sensor Circuit Low Input 1. No DTC relating to MAP sensor, TPS,
ECT sensor, injector control circuit and
ignition control circuit.
2. Engine is running.
3. Vehicle speed is below 3km/h in power
condition or 2km/h in deceleration
condition.ECM uses 0km/h condition as
substitute.VSS circuit correct condition. 1. Sensor harness open circuit, short to
ground circuit or short to voltage circuit.
2. Poor connector connection.
3. VSS malfunction.
4. ECM malfunction.J2-23
P0562 D System Voltage Low Battery voltage is below 11V. No fail-safe function. Battery voltage is between 11V and 16V. 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.-
P0563 A System Voltage High Battery voltage is above 16V.1. Charge system malfunction.
2. Battery jump start cable misconnect.
3. ECM malfunction.-
P0601 A ECM Memory Checksum ECM memory area error. Engine control disabled. Memory are is OK. ECM malfunction. -
P0602 - ECU Programming Error ECM memory area error. Engine control disabled. Memory are is OK. ECM is not programmed. -
P0650 A Malfunction Indicator Lamp (MIL) Control
Circuit MalfunctionCheck engine lamp circuit open, short to
ground or short to voltage circuit.No fail-safe function. Check engine lamp circuit is correct
condition.1. Solenoid harness open circuit, short to
ground or short to voltage circuit.
2. Solenoid malfunction.
3. ECM malfunction.J2-32 Code Type DTC Name DTC Setting Condition Fail-Safe (Back Up) Recovery Condition Related Failure Parts Related
ECM
Pin No.