2004 ISUZU TF SERIES oil

4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS 6E–217
DIAGNOSTIC TROUBLE CODE (DTC) P0380 (SYMPTOM CODE 4)
(FLASH CODE 66) GLOW RELAY CIRCUIT VOLTAGE LOW
DIAGNOSTIC TROUBLE CODE (DTC) P0380 (SYMPTOM CODE 8)
(FLASH CODE 66) GLOW RELAY CIRCUIT VOLTAGE HIGH
Condition for setting the DTC and action taken when the DTC sets
Circuit Description
The voltage on the coil of the relay glow plug is supplied
by the relay engine control module (ECM) main. The
ECM switches glow relay to operate glow plug depends
on the coolant temperature.
In the after glow phase the lamp is not illuminated but
the glow plugs remain active for a certain period
depending on engine coolant temperature.
Diagnostic Aids
An intermittent may be caused by the following:
Poor connections.
Misrouted harness.
Rubbed through wire insulation.
Broken wire inside the insulation.
Check for the following conditions:
Flash
CodeCode Symptom
CodeMIL DTC Name DTC Setting Condition Fail-Safe (Back Up)
66 P0380 4 ON Glo w Re la y Circuit Volta ge
Lo wGlow relay circuit open or
sho rt to ground circuit.No fa il-sa fe fun ctio n.
8 ON Glo w Re la y Circuit Volta ge
HighGlo w re la y circuit short to vo lt-
age circuit.

6E –218 4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS
 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. 
Damaged harness-Inspect the wiring harness for
damage. If the harness appears to be OK, observe
the DTC P0380 display on the Tech2 while moving
connectors and wiring harnesses. A change in the
display will indicate the location of the fault.
Diagnostic Trouble Code (DTC) P0380 (Symptom Code 4) (Flash Code 66) Glow Relay Circuit Voltage Low
Step Action Value(s) Yes No
1Was the “On-Board Diagnostic (OBD) System Check ”
performed?
— Go to Step 2 Go 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 As Stored By ECU ” in
“ F0: Diagnostic Trouble Codes ”.
Is the DTC P0380 (Symptom Code 4) stored as
“ Present Failure ”? —Go to Step 3 Refer to
Diagnostic Aids and Go to Step
3
3 1. Using the Tech 2, ignition “On ” and engine “Off ”.
2. Select “F1: Clear DTC Information ” in “F0:
Diagnostic Trouble Codes ” with the Tech 2 and
clear the DTC information.
3. Operate the vehicle and monitor the “F0: Read
DTC Infor As Stored By ECU ” in the “F0:
Diagnostic Trouble Codes ”.
Was the DTC P0380 (Symptom Code 4) stored in this
ignition cycle? —Go to Step 4 Refer to
Diagnostic Aids and Go to Step
4
4 Check for poor/faulty connection at the glow 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 glow relay. 1. Ignition “Off ”, engine “Off ”.
2. Remove the glow relay from the relay box .
3. Check the relay coil.
Was the DVM indicated specified value?
Approx imately 105
Go to Step 6 Replace glow
relay and verify repair
94
3
4
2
1
X-5
C-57
Grow Relay




4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS 6E –229
Diagnostic Trouble Code (DTC) P0400 (Symptom Code 3) (Flash Code 32)
Exhaust Gas Recirculation Flow Excessive Detected
Step Action Value(s) Yes No
1Was the “On-Board Diagnostic (OBD) System Check ”
performed?
— Go to Step 2 Go 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 As Stored By ECU ” in
“ F0: Diagnostic Trouble Codes ”.
Is the DTC P0400 (Symptom Code 3) stored as
“ Present Failure ”? —Go to Step 3 Refer to
Diagnostic Aids and Go to Step
3
3 1. Using the Tech 2, ignition “On ” and engine “Off ”.
2. Select “F1: Clear DTC Information ” in “F0:
Diagnostic Trouble Codes ” with the Tech 2 and
clear the DTC information.
3. Operate the vehicle and monitor the “F0: Read
DTC Infor As Stored By ECU ” in the “F0:
Diagnostic Trouble Codes ”.
Was the DTC P0400 (Symptom Code 3) stored in this
ignition cycle? —Go to Step 4 Refer to
Diagnostic Aids and Go to Step
4
4 Remove the MAF & IAT sensor assembly and check for the following conditions.
 Objects blocking the air cleaner.
 Objects blocking the MAF sensor.
 Vacuum leaking at intake duct.
 Objects blocking the turbocharger.
If a problem is found, repair as necessary.
Was the problem found? —Verify repair Go to Step 5
5 Remove the MAF & IAT sensor assembly and visually check.
Was the problem found? —Go to Step 6 Go to Step 8
6 Substitute a known good MAF & IAT sensor assembly and recheck.
Was the problem solved? —Go to Step 7 Go to Step 8
7 Replace the MAF & IAT sensor assembly. Is the action complete? —Verify repair —
8 Using the DVM and check the EGR EVRV. 1. Ignition “Off ”, engine “Off ”.
2. Disconnect the EGR EVRV connector.
3. Measure the resistance of EGR EVRV solenoid coil.
Does the tester indicate standard resistance?
Approx imately 14
at 20 °CGo to Step 11 Go to Step 9
1
2
EGR EVRV
1
2

6E –232 4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0400 (Symptom Code 4) (Flash Code 32)
Exhaust Gas Recirculation Circuit Short to Ground or Open Circuit
Step Action Value(s) Yes No
1Was the “On-Board Diagnostic (OBD) System Check ”
performed?
— Go to Step 2 Go 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 As Stored By ECU ” in
“ F0: Diagnostic Trouble Codes ”.
Is the DTC P0400 (Symptom Code 4) stored as
“ Present Failure ”? —Go to Step 3 Refer to
Diagnostic Aids and Go to Step
3
3 1. Using the Tech 2, ignition “On ” and engine “Off ”.
2. Select “F1: Clear DTC Information ” in “F0:
Diagnostic Trouble Codes ” with the Tech 2 and
clear the DTC information.
3. Operate the vehicle and monitor the “F0: Read
DTC Infor As Stored By ECU ” in the “F0:
Diagnostic Trouble Codes ”.
Was the DTC P0400 (Symptom Code 4) stored in this
ignition cycle? —Go to Step 4 Refer to
Diagnostic Aids and Go to S tep
4
4 Check for poor/faulty connection at the EGR EVRV 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 EGR EVRV. 1. Ignition “Off ”, engine “Off ”.
2. Disconnect the EGR EVRV connector.
3. Measure the resistance of EGR EVRV solenoid coil.
Does the tester indicate standard resistance?
Approx imately 14
at 20 °CGo to Step 6Go to Step 9
9712
C-115
C-57
1
2
EGR EVRV
1
2

4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS 6E –235
Diagnostic Trouble Code (DTC) P0400 (Symptom Code 5) (Flash Code 32)
Exhaust Gas Recirculation Flow Insufficient Detected
Step Action Value(s) Yes No
1Was the “On-Board Diagnostic (OBD) System Check ”
performed?
— Go to Step 2 Go 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 As Stored By ECU ” in
“ F0: Diagnostic Trouble Codes ”.
Is the DTC P0400 (Symptom Code 5) stored as
“ Present Failure ”? —Go to Step 3 Refer to
Diagnostic Aids and Go to Step 3
3 1. Using the Tech 2, ignition “On ” and engine “Off ”.
2. Select “F1: Clear DTC Information ” in “F0:
Diagnostic Trouble Codes ” with the Tech 2 and
clear the DTC information.
3. Operate the vehicle and monitor the “F0: Read
DTC Infor As Stored By ECU ” in the “F0:
Diagnostic Trouble Codes ”.
Was the DTC P0400 (Symptom Code 5) stored in this
ignition cycle? —Go to Step 4 Refer to
Diagnostic Aids and Go to Step 4
4 Visually check the EGR control vacuum hose. If the hose is clogged or disconnected, repair as
necessary.
Was the problem found? —Verify repair Go to Step 5
5 Using the DVM and check the EGR EVRV. 1. Ignition “Off ”, engine “Off ”.
2. Disconnect the EGR EVRV connector.
3. Measure the resistance of EGR EVRV solenoid coil.
Does the tester indicate standard resistance?
Approx imately 14
at 20 °C Go to Step 8 Go to Step 6
6 Substitute a known good EGR EVRV and recheck. Was the problem solved? —Go to Step 7 Go to Step 8
7 Replace the EGR EVRV. Is the action complete? —Verify repair —
1
2
EGR EVRV
1
2

6E –238 4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0400 (Symptom Code 8) (Flash Code 32)
Exhaust Gas Recirculation Circuit Short to Battery
Step Action Value(s) Yes No
1Was the “On-Board Diagnostic (OBD) System Check ”
performed?
— Go to Step 2 Go 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 As Stored By ECU ” in
“ F0: Diagnostic Trouble Codes ”.
Is the DTC P0400 (Symptom Code 8) stored as
“ Present Failure ”? —Go to Step 3 Refer to
Diagnostic Aids and Go to Step
3
3 1. Using the Tech 2, ignition “On ” and engine “Off ”.
2. Select “F1: Clear DTC Information ” in “F0:
Diagnostic Trouble Codes ” with the Tech 2 and
clear the DTC information.
3. Operate the vehicle and monitor the “F0: Read
DTC Infor As Stored By ECU ” in the “F0:
Diagnostic Trouble Codes ”.
Was the DTC P0400 (Symptom Code 8) stored in this
ignition cycle? —Go to Step 4 Refer to
Diagnostic Aids
4 Check for poor/faulty connection at the EGR EVRV 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 EGR EVRV. 1. Ignition “Off ”, engine “Off ”.
2. Disconnect the EGR EVRV connector.
3. Measure the resistance of EGR EVRV solenoid coil.
Does the tester indicate standard resistance?
Approx imately 14
at 20 °CGo to Step 6Go to Step 8
9712
C-115
C-57
1
2
EGR EVRV
1
2

4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS 6E –257
7 Using the DVM and check the ECM main relay.
1. Ignition “Off ”, engine “Off ”.
2. Remove the ECM main relay from the relay box .
3. Check the relay coil.
Was the DVM indicated specified value?
120-150
Go to Step 8 Replace ECM
main relay and verify repair
8 Check for poor/faulty connection of the ECM ground at the body. If a poor/faulty connection is found, repair
as necessary.
Was the problem found?
— Verify repair Go to Step 9
9 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 10
10 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 —
Step Action Value(s) Yes No
ECM Main Relay


 




C-109

6E–268 4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS
DIAGNOSTIC TROUBLE CODE (DTC) P0645 (SYMPTOM CODE 4)
(FLASH CODE 46) A/C COMPRESSOR RELAY CIRCUIT VOLTAGE LOW
DIAGNOSTIC TROUBLE CODE (DTC) P0645 (SYMPTOM CODE 8)
(FLASH CODE 46) A/C COMPRESSOR RELAY CIRCUIT VOLTAGE HIGH
Condition for setting the DTC and action taken when the DTC sets
Circuit Description
The voltage on the coil of the A/C compressor is
supplied by the ECM main relay. The ECM switches A/C
compressor relay to operate A/C compressor depends
on the A/C request signal and certain setting conditions.
Diagnostic Aids
An intermittent may be caused by the following:
Poor connections.
Misrouted harness.
Rubbed through wire insulation.
Broken wire inside the insulation.
Flash
CodeCode Symptom
CodeMIL DTC Name DTC Setting Condition Fail-Safe (Back Up)
46 P0645 4 ON A/C Co mpressor Re lay Circuit
Voltage LowA/C co mpre sso r re la y circuit
open or short to ground cir-
cuit.No fa il-sa fe fun ctio n.
8 ON A/C Co mpressor Re lay Circuit
Vo lta ge High A/C co mpre sso r re la y circuit
short to voltage circuit.