relay ISUZU TF SERIES 2004 Workshop Manual

3.5L ENGINE DRIVEABILITY AND EMISSIONS 6E-125
Step Action Value (s) Yes No
12
 Using the DVM and check the A/C compressor relay
ground circuit.
1. Ignition "Off", engine "Off".
2. Disconnect the ECM connector.
3. Remove the A/C compressor relay from the relay
box.
4. Check the circuit for open or short to ground circuit.
Was the problem found?
E-61(B)
X-14









- Repair faulty
harness and
verify repair Go to Step 13
13
Using the DVM and check the A/C magnet clutch
power supply circuit.
1. Using the Tech 2, ignition "On" and engine "Off".
2. Select the "Miscellaneous Test" and perform the
"A/C Clutch Relay" in the "Relays".
3. Operate the Tech 2 in accordance with procedure.
4. Disconnect the A/C clutch connector. Check the
circuit for open or short to ground circuit.
Was the DVM indicated specified value?
E-2
V



10 – 14.5V Go to Step 27 Go to Step 14
14
Repair the open or short to ground circuit between the
A/C compressor relay and A/C magnet clutch.
Is the action complete?
E-2X-14






- Verify repair -

6E-126 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Step Action Value (s) Yes No
15
Check for poor/faulty connection at the thermo relay,
triple pressure switch, thermostat or ECM connector. If
a poor/faulty connection is found, repair as necessary.
Was the problem found?
E-61(B)
X-15







C-24C-55









- Verify repair Go to Step 16
16
 Using the DVM and check the thermo relay.
1. Ignition "Off", engine "Off".
2. Remove the thermo relay from the relay box.
3. Check the relay coil.
Was the DVM indicated specified value?
X-15






Approximately
140

Go to Step 17 Replace thermo
relay and verify
repair
17
 Using the DVM and check the thermo relay power
supply circuit.
1. Ignition "On", engine "Off".
2. Remove the thermo relay from the relay box.
3. Check the circuit for open or short to ground circuit.
Was the DVM indicated specified value?
X-15





VV

10 – 14.5V Go to Step 19 Go to Step 18
18
Repair the open or short to ground circuit between the
"A/C" fuse (10A) and thermo relay.
Is the action complete?
- Verify repair -

3.5L ENGINE DRIVEABILITY AND EMISSIONS 6E-127
Step Action Value (s) Yes No
19
Using the DVM and check the triple pressure switch
circuit.
1. Ignition "On", engine "Off".
2. Turn "On" blower motor.
3. Disconnect the triple pressure switch connector.
4. Check the circuit for open or short to ground circuit.
Was the DVM indicated specified value?
C-24
V



10 – 14.5V Go to Step 21 Go to Step 20
20
Repair the open or short to ground circuit between the
thermo relay and triple pressure switch.
Is the action complete?
C-24
X-15





- Verify repair -
21
Using the DVM and check the triple pressure switch.
1. Ignition "Off", engine "Off".
2. Disconnect the triple pressure switch connector.
3. Check the switch.
Was the switch closed?
Triple Pressure
SW






- Go to Step 23 Go to Step 22
22
Replace the triple pressure switch.
Is the action complete?
- Verify repair -

6E-128 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Step Action Value (s) Yes No
23
Using the DVM and check the thermostat circuit.
1. Ignition "On", engine "Off".
2. Turn "On" blower motor.
3. Disconnect the triple pressure switch connector.
4. Check the circuit for open or short to ground circuit.
Was the DVM indicated specified value?
C-55
V



10 – 14.5V Go to Step 25 Go to Step 24
24
Repair the open or short to ground circuit between the
triple pressure switch and thermostat.
Is the action complete?
C-55C-24



- Verify repair -
25
Replace the thermostat.
Is the action complete?
- Verify repair -
26
Using the DVM and check the thermo relay input
circuit.
1. Ignition "Off", engine "Off".
2. Disconnect the ECM connector.
3. Remove the thermo relay from the relay box.
4. Check the circuit for open or short to ground circuit.
Was the problem found?
E-61(B)
X-15










- Repair faulty
harness and
verify repair Go to Step 28
27
Replace the A/C compressor.
Was the problem solved?
- Verify repair -

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

6E-210 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Step Action Value (s) Yes No
7
Repair the open or short to ground circuit between the
fuel pump relay and O2 sensor heater for the affected
cylinder.
Was the problem found?
- Verify repair Go to Step 8
8
Repair the open circuit between the O2 sensor heater
and engine ground for the affected cylinder.
Was the problem found?
- Verify repair Go to Step 9
9
Using the DVM and check the O2 sensor heater circuit
for the affected bank.
1. Ignition "Off", engine "Off".
2. Disconnect the O2 sensor connector for the
affected bank.
3. Check the circuit for short circuit.
Was the tester indicated specified value?
O2 Sensor BANK1/BANK2







Approximatly
16.5 at 20

Go to Step 12
Approximataly
0: Go to Step
10
No continuitly: Go
to Step 11
10
Repair the short circuit between the O2 sensor heater
power supply and ground circuit.
Is the action complete?
- Verify repair -
11
Replace the O2 sensor for the affected bank.
Was the problem solved?
- Verify repair Go to Step 12
12
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 13
13
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-230 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Step Action Value (s) Yes No
7
Using the DVM and check the injector power supply
circuit.
1. Ignition "On", engine "Off".
2. Disconnect the injector connector for the affected
cylinder.
3. Check the circuit for open circuit.
Was the DVM indicated specified value?
E-6/E-7/E-8/E-9/
E-51/E-52
V



Battery voltage
Go to Step 9
Go to Step 8
8
Repair the open or short to ground circuit between the
ECM main relay and injector for the affected cylinder.
Is the action complete?
- Verify repair -
9
Using the DVM and check the injector signal 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 injector connector for the affected
cylinder.
4. Check the circuit for open or short to ground circuit.
Was the problem found?
A36
Breaker Box


E-6


No.1 Cylinder

B3
Breaker Box


E-7


No.2 Cylinder

3.5L ENGINE DRIVEABILITY AND EMISSIONS 6E-261
Step Action Value (s) Yes No
8
Repair the open or short to ground circuit between the
ECM main relay and EGR valve.
Is the action complete?
- Verify repair -
9

Using the DVM and check the EGR valve solenoid
signal 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 EGR valve connector.
4. Check the circuit for open, short to sensor ground
or short to ground circuit.
Was the problem found?
A5A22


Breaker Box
E-76







Breaker box is not available:
1. Ignition "Off", engine "Off".
2. Disconnect the EGR valve connector and ECM
connector.
3. Check the circuit for open, short to sensor ground
or short to ground circuit.
Was the problem found?
E-60(A)




E-76









-

Repair faulty
harness and
verify repair

Go to Step 10

3.5L ENGINE DRIVEABILITY AND EMISSIONS 6E-299
Step Action Value (s) Yes No
6
Remove the IAC Valve and visually check.
Was the problem found?
- Go to Step 12 Go to Step 7
7
Using the DVM and check the IAC Valve coil at IAC
Valve.
1. Ignition "Off", engine "Off".
2. Disconnect the IAC Valve connector.
3. Check the coil resistance.
Does the tester indicate standard resistance as shown
in the following table?
IAC Valve














Measurement Terminal Resistance ()
1 - 2 Approximately 50
2 - 3 Approximately 50
1 – 3 Approximately 100
4 - 5 Approximately 50
5 - 6 Approximately 50
4 - 6 Approximately 100
-
Go to Step 8
Go to Step 12
8
Using the DVM and check the IAC Valve power supply
circuit.
1. Ignition "Off", engine "Off".

2. Disconnect the IAC Valve connector and ECM
main relay
3. Check the circuit for open circuit.
Was the problem found?
X-13E-70











-
Repair faulty
harness and
verify repair
Go to Step 9

6E-374 3.5L ENGINE DRIVEABILITY AND EMISSIONS
FUEL PRESSURE RELIEF
Caution:
To reduce the risk of the fire and personal injury, it
is necessary to relive the fuel system pressure
before servicing the fuel system components.
Caution:
After relieving the fuel system pressure, a small
amount of fuel may be released when servicing fuel
lines or connections. Reduce the chance o
f
personal injury by covering the fuel line fitting with
a short towel before disconnecting the fittings. The
towel will absorb any fuel that may leak out. When
the disconnect is completed, place the towel in an
approved container.

1. Remove the fuel filler cap.
2. Remove the fuel pump relay.
3. Start the engine and allow it to stall.
4. Crank the engine for about 30 seconds.
5. Disconnect the negative battery cable.



FUEL RAIL ASSEMBLY

Removal Procedure
NOTE:
 Do not attempt to remove the fuel inlet fitting on
the fuel rail. It is staked in place. Removing the
fuel inlet fitting will result in damage to the fuel
rail or the internal O-ring seal.
 Use care when removing the fuel rail assembly in
order to prevent damage to the injector electrical
connector terminals and the injector spray tips.
 Fittings should be capped and holes plugged
during servicing to prevent dirt and othe
r
contaminants from entering open lines and
passages.
Important: Before removal, the fuel rail assembly may
be cleaned with a spray type engine cleaner. Follow the
spray package instructions. Do not immerse the fuel
rails in liquid cleaning solvent.
1. Depressurize the fuel system. Refer to Fuel
Pressure Relief Procedure in this Section.
2. Disconnect the negative battery cable.
3. Remove the engine cover.
4. Disconnect the accelerator pedal cable from throttle
body and cable bracket.

5. Disconnect the connectors from, solenoid valve,
sensing valve.
6. Disconnect the vacuum hose on canister solenoid
and positive crankcase ventilation hose.
7. Remove the common chamber Refer to the
common chamber in Engine Mechanical.
1. Lift up carefully on the fuel injectors. Do no
t
separate the fuel injectors from the fuel rail.
2. If an injector becomes separated from the fuel
rail, the infector O-ring seals and the retaine
r
clip must be replaced.
3. Drain residual fuel into an approved container.




060RW044
8. If removal of the fuel pressure regulator is
necessary, refer to Fuel Pressure Regulator.
9. If removal of the fuel injectors is necessary, refer to
Fuel Injectors.

Installation Procedure
1. If the fuel injectors were removed, install them.
Refer to Fuel Injectors.
2. If the fuel pressure regulator was removed, install
it. Refer to Fuel Pressure Regulator.