2004 ISUZU TF SERIES relay

4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS 6E–89
18 Brake Switch 2 Active/
InactiveInactive Inactive Inactive This displays operating status of the brake switch. This
should display "Active" when the brake pedal is stepped
on.
19 Clutch Sw itch Activ e /
InactiveInactive Inactive Inactive This displays operating status of the clutch switch. This
should display "Active" when the clutch pedal is stepped
on.
20 Neutra l Switch On/Off On On On This displa ys o pe rating status of the neutra l switch. This
should display "On" when the gear position is neutral.
21 A/C Informa tion
SwitchActive 12V/
Inactive 0VInactive 0V Inactive 0V Inactive 0V This displays the air conditioner request signal. This
should display "Active 12V" when the air conditioner switch
is switched on.
22 Dia gnostic Re quest Activ e 0V/
Inactive 12VIna ctiv e
12VInactive
12VIna ctiv e
12VThis display s the dia gnostic reque st signal. This sho uld
display "Inactive 12V" when the Tech 2 is connected.
23 System Voltage V 10 - 14 10 - 14 10 - 14 This displays the system voltage measured by the ECM at
ignition feed.
24 Ma in Re la y Activ e /
InactiveActive Active Active This displays operating status for the ECM main relay. This
should display "Active" when the key switch is turned on
and while engine is running.
25 Glow Time Relay Activ e 0V/
Inactive12VIna ctiv e
12VInactive
12VIna ctiv e
12VThis displays operating status for the glow relay. This
should display "Inactive 12V" when the engine is warm
uppe d.
26 Check Engine Light On/Off Off Off Off This displays operating status for the Check Engine Lamp.
This should display "On" when the Check Engine Lamp is
turned on.
27 Glow Time Telltale On/Off Off Off Off This displays operating status for the glow indicator lamp.
This sho uld display "On" whe n the glo w la mp is turne d o n.
28 Desired Engine Idle
Speedrpm 730 730 730 The desired engine idle speed that the ECM commanding.
The ECM compensates for various engine loads based on
engine coolant temperature.
29 A/C Re que st Activ e 0V/
Inactive 12VIna ctiv e
12VInactive
12VIna ctiv e
12VThis displays operating status of the A/C compressor. This
should display "Active 0V" when the compressor relay is
operated.
30 Immo bilize r Activ e /
InactiveInactive Inactive Inactive This should display "Inactive" when the immobilizer is
correctly operated.
31 Immo bilize r Signal Rece iv ed/
Not
Rece iv edNo t
Receive dNo t
Re ceive dNot
Re ce iv e dThis sho uld displa y "No t Receive d" whe n the immo bilize r is
not activated.
32 Immo bilize r Function
ProgrammedYes/ No Yes Yes Yes This should display "Yes" when the immobilizer is correctly
programmed.
33 EGR Pulse Ratio
(Ex ha ust Ga s
Recirculatio n)% 70 70 70 This displays the duty signal from the ECM to control the
EGR flow amount. Tech 2 Parameter Units Idle 1500rpm 2000rpm Description

4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS 6E–91
18 Brake Switch 2 Active/
InactiveInactive Inactive Inactive This displays operating status of the brake switch. This
should display "Active" when the brake pedal is stepped
on.
19 Clutch Switch (M/T
On ly )Active/
InactiveInactive Inactive Inactive This displays operating status of the clutch switch. This
should display "Active" when the clutch pedal is stepped
on.
20 Neutra l Switch On/Off On On On This displa ys o pe rating status of the neutra l switch. This
should display "On" when the gear position is neutral (M/T)
or P, N positio n (A/T).
21 A/C Informa tion
SwitchActive 12V/
Inactive 0VInactive 0V Inactive 0V Inactive 0V This displays the air conditioner request signal. This
should display "Active 12V" when the air conditioner switch
is switched on.
22 Dia gnostic Re quest Activ e 0V/
Inactive 12VIna ctiv e
12VInactive
12VIna ctiv e
12VThis displays the diagnostic request signal. This should
display "Inactive 12V" when the Tech 2 is connected.
23 System Voltage V 10 - 15 10 - 15 10 - 15 This displays the system voltage measured by the ECM at
ignition feed.
24 Ma in Re la y Activ e /
InactiveActive Active Active This displays operating status for the ECM main relay. This
should display "Active" when the key switch is turned on
and while engine is running.
25 Glow Time Relay Activ e 0V/
Inactive12VIna ctiv e
12VInactive
12VIna ctiv e
12VThis displays operating status for the glow relay. This
should display "Inactive 12V" when the engine is warm
uppe d.
26 Check Engine Light On/Off Off Off Off This displays operating status for the Check Engine Lamp.
This should display "On" when the Check Engine Lamp is
turned on.
27 Glow Time Telltale On/Off Off Off Off This displays operating status for the glow indicator lamp.
This sho uld display "On" whe n the glo w la mp is turne d o n.
28 Desired Engine Idle
Speedrpm 700 700 700 The desired engine idle speed that the ECM commanding.
The ECM compensates for various engine loads based on
engine coolant temperature.
29 A/C Re que st Activ e 0V/
Inactive 12VIna ctiv e
12VInactive
12VIna ctiv e
12VThis displays operating status of the A/C compressor. This
should display "Active 0V" when the compressor relay is
operated.
30 Immo bilize r Activ e /
InactiveInactive Inactive Inactive This should display "Inactive" when the immobilizer is
correctly operated.
31 Immo bilize r Signal Rece iv ed/
Not
Rece iv edNo t
Receive dNot
Re ceive dNot
Re ce iv e dThis sho uld displa y "No t Receive d" whe n the immo bilize r is
not activated.
32 Immo bilize r Function
ProgrammedYes/ No Yes Yes Yes This should display "Yes" when the immobilizer is correctly
programmed.
33 EGR Pulse Ratio
(Ex ha ust Ga s
Recirculatio n)% 85 - 90 85 - 90 85 - 90 This displays the duty signal from the ECM to control the
EGR flow amount. Tech 2 Parameter Units Idle 1500rpm 2000rpm Definition

6E–92 4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS
MISCELLANEOUS TEST
The state of each circuit can be tested by using
miscellaneous test menus. Especially when DTC
cannot be detected, a faulty circuit can be diagnosed by
testing each circuit by means of these menus.
Even DTC has been detected, the circuit tests using
these menus could help discriminate between a
mechanical trouble and an electrical trouble.
Connect Tech 2 and select "Powertrain", "4JA1-TC
Bosch" or "4JH1-TC Bosch" & "Miscellaneous Test".
F0: Lamps
F0: Glow Time Telltale Test
When the Tech 2 is operated, "Glow Time Indicator
Lamp" is turned on or off.
The circuit is correct if the "Glow Time Indicator Lamp"
in the instrument panel is turned on or off in accordance
with this operation.
F1: Relays
F0: Glow Time Relay Test
When the Tech 2 is operated, glow relay turns ON or
OFF.
The circuit is correct if glow relay is operated in
accordance with this operation.
F2: Solenoids
F0: EGR Solenoid Test
When the Tech 2 is operated, control duty ratio of EGR
EVRV changes to 5% to 95%.
The circuit is correct if glow relay is operated in
accordance with this operation.
Press "Active" key.
Then, EVRV duty ratio increases to 95%
Press "Inactive key".
EVRV duty ratio decreases to 5%F3: Engine Speed (RPM) Control
When the Tech 2 is operated, "Desired Idle Speed"
increases 50rpm-by-50rpm up to 1200rpm.
The circuit is correct if engine speed is changed in
accordance with this operation.
Press "Increase" key.
Then, Desired Idle speed is increases
50rpm-by-50rpm up to 1200rpm. Engine speed is
also
EGR Solenoid Test
Desired Mass Air Flow 470 mg/strk
Mass Air Flow 450 mg/strk
Engine Speed 700 rpm
Exhaust Gas Recirculation 95%
Engine Speed (RPM) Control
Engine Speed 850 rpm
Desired Idle Speed 850 rpm
Injection Quantity 7.5 mg/ strk

4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS 6E–119
43 P0335 B ON Crankshaft Position Sensor
Circuit Malfunction1. Engine speed is more
t h a n 6 6 5 r p m .
2. CKP sensor pulse width
error.When pump camshaft speed
sensor is OK:
ECM uses doubled pump
camshaft speed as substitute
engine speed.
When pump camshaft speed
s e n s o r i s n o t O K :
1. MAB (fuel cutoff solenoid
v a l v e ) i s o p e r a t e d .
2. Desired injection quantity
becomes 0mg/strk. ECM detects correct CKP
pulse width.1 . D u r i n g e n g i n e r u n :
1. CKP sensor harness
open circuit, short to
ground or short to
voltage circuit.
2. Poor connector
c o n n e c t i o n .
3. CKP sensor malfunction.
4. Pulse sensing gap
i n c o r r e c t .
5 . P u l s e r m a l f u n c t i o n .
6. Electrical interference.
7. Magnetic interference.
8. ECM malfunction.9 0 /
9 8 /
101P1335 (A)
D ON Crankshaft Position Sensor
Circuit Malfunction1. No pump camshaft
s p e e d s e n s o r e r r o r .
2. "Crankshaft Position
Sensor Circuit
Malfunction (Symptom
Code B)" is not stored.
3 . E n g i n e s p e e d i s 0 r p m .
4. Doubled pump camshaft
speed is more than
50rpm.When pump camshaft speed
s e n s o r i s O K :
ECM uses doubled pump
camshaft speed as substitute
engine speed.
Other than pump camshaft
s p e e d s e n s o r i s O K :
Fuel injection quantity is
reduced.1. Engine speed is more
than 0rpm.
2. Doubled pump camshaft
speed is below 100rpm.During engine crank:
1. CKP sensor harness
open circuit, short to
ground or short to
voltage circuit.
2. Poor connector
c o n n e c t i o n .
3. CKP sensor malfunction.
4. Pulse sensing gap
i n c o r r e c t .
5 . P u l s e r m a l f u n c t i o n .
6. Electrical interference.
7. Magnetic interference.
8. ECM malfunction.9 0 /
9 8 /
101P1135 (A)
E ON Engine Speed Input Circuit
Range/PerformanceEngine speed is more than
5700rpm.When intermittent
malfunction:
1. MAB (fuel cutoff solenoid
v a l v e ) i s o p e r a t e d .
2. Desired injection quantity
b e c o m e s 0 m g / s t r k .
When preliminary
malfunction:
ECM uses doubled pump
camshaft speed as substitute
engine speed.Engine speed is below
5700rpm.1. Engine over-running.
2. CKP sensor malfunction.























3 . P u l s e r m a l f u n c t i o n .
4. ECM malfunction.
9 0 /
9 8 /
101—
66 P0380 4 ON Glow Relay Circuit Voltage
LowGlow relay circuit open or
short to ground circuit.No fail-safe function. Glow relay circuit is correct
condition.1. Glow relay circuit open or
short to ground circuit.
2. Glow relay malfunction.
3. ECM malfunction.94 —
8 ON Glow Relay Circuit Voltage
HighGlow relay circuit short to
voltage circuit.ECM malfunction.
—— Flash
CodeCodeSymptom
CodeMILDTC Name DTC Setting Condition Fail-Safe (Back Up) Recovery Condition Related Failure PartsRelated
ECM Pin
No.Related
Multiple
DTC4JA1-TC
(MT)4JH1-TC
(MT)4JH1-TC
(AT)

4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS 6E–123
46 P0645 4 ON A/C Compressor Relay
Circuit Voltage LowA/C compressor relay circuit
open or short to ground
circuit.No fail-safe function. A/C compressor relay circuit
is correct condition.1. A/C compressor relay
circuit open or short to
g r o u n d c i r c u i t .
2. Poor connector
c o n n e c t i o n .
3. A/C compressor relay
m a l f u n c t i o n .
4. ECM malfunction.41 —
8 ON A/C Compressor Relay
Circuit Voltage High A/C compressor relay circuit
short to voltage circuit.ECM malfunction.
——
25 P0703 A ON Brake Switch Circuit
Malfunction1. Throttle position is more
t h a n 0 % .
2. Engine speed is more
than 693rpm (4JA1-TC)
or 665rpm (4JH1-TC).
3. Vehicle speed is more
t h a n 0 k m / h .
4. Brake switch 1 signal and
brake switch 2 signal are
differently inputted to the
ECM since the ignition
switch was turned on.No fail-safe function. Brake switch 1 signal and
brake switch 2 signal are
correctly inputted to the
ECM.1. Brake switch 1 circuit
open, short to ground or
short to voltage circuit.
2. Poor connector
c o n n e c t i o n .
3. Brake switch 1
m a l f u n c t i o n .
4. ECM malfunction.30 —
B ON Brake Switch Circuit
Malfunction1. Throttle position is more
t h a n 0 % .
2. Engine speed is more
than 693rpm (4JA1-TC)
or 665rpm (4JH1-TC).
3. Vehicle speed is more
t h a n 0 k m / h .
4. Brake switch 1 signal and
brake switch 2 signal are
differently inputted to the
ECM.1. Brake switch 2 circuit
open or short to ground
c i r c u i t .
2. Poor connector
c o n n e c t i o n .
3. Brake switch 2
m a l f u n c t i o n .
4. ECM malfunction.65 —
57 P0704 6 ON Clutch Switch Input Circuit
MalfunctionClutch signal does not
change between vehicle
speed 1.5km/h and 80km/h
since ignition switch was
tuned on. No fail-safe function. Clutch signal correctly
changes.1. Clutch switch circuit
open, short to ground or
short to voltage circuit.
2. Poor connector
c o n n e c t i o n .
3. Clutch switch
m a l f u n c t i o n .
4. ECM malfunction.31 — —
86 P1105 1 ON Barometric Pressure Sensor
Circuit High InputBarometric pressure sensor
output voltage is more than
4.4V.ECM uses 1013hpa
condition as substitute.Barometric pressure sensor
output voltage is below 4.4V.ECM malfunction.
——
2 ON Barometric Pressure Sensor
Circuit Low InputBarometric pressure sensor
output voltage is below 1.5V.Barometric pressure sensor
output voltage is more than
1.5V.ECM malfunction.
—— Flash
CodeCodeSymptom
CodeMILDTC Name DTC Setting Condition Fail-Safe (Back Up) Recovery Condition Related Failure PartsRelated
ECM Pin
No.Related
Multiple
DTC4JA1-TC
(MT)4JH1-TC
(MT)4JH1-TC
(AT)

6E–126 4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS
55 P1605 E ON EEPROM Defect EEPROM checksum does
not match with the read
check sum during
initialization of the ECM.EEPROM checksum match
with the read check sum
during initialization of the
ECM.ECM malfunction.
——
56 P1610 A - Security Key and Security
Code not ProgrammedImmobilizer functions are not
programmed in the ECM.1 . E n g i n e d o e s n o t s t a r t .
2. Check engine lamp flash. No recovery. ECM malfunction.
— B****
56 P1611 A - Wrong Security Code
EnteredReceived security code is not
correct.1 . E n g i n e d o e s n o t s t a r t .
2. Check engine lamp flash. N o r e c o v e r y . 1 . E C M m a l f u n c t i o n .
2. Immobilizer control unit
m a l f u n c t i o n .
3. Transponder key
malfunction.— B****
56 P1612 A - Immobilizer No or Wrong
SignalReceived challenge signal is
not correct or not received.1 . E n g i n e d o e s n o t s t a r t .
2. Check engine lamp flash. No recovery. 1. ECM and immobilizer
control unit
communication circuit
open circuit, short to
ground circuit or short to
voltage circuit.
2 . E C M m a l f u n c t i o n .
3. Immobilizer control unit
m a l f u n c t i o n .
4. Transponder key
malfunction.2 7 /
35B****
56 P1613 A - Immobilizer No or Wrong
SignalReceived response signal is
not correct or not received.1 . E n g i n e d o e s n o t s t a r t .
2. Check engine lamp flash. No recovery. 1. ECM and immobilizer
control unit
communication circuit
open circuit, short to
ground circuit or short to
voltage circuit.
2 . E C M m a l f u n c t i o n .
3. Immobilizer control unit
m a l f u n c t i o n .
4. Transponder key
malfunction.2 7 /
35B****
56 P1614 A - Wrong Transponder Key Received response signal is
not correct from the
transponder key.1 . E n g i n e d o e s n o t s t a r t .
2. Check engine lamp flash. N o r e c o v e r y . 1 . E C M m a l f u n c t i o n .
2. Immobilizer control unit
m a l f u n c t i o n .
3. Transponder key
malfunction.— B****
76 P1625 A OFF ECM Main Relay Switched
Off Too EarlyWhen ignition switch was
turned off, timing of the ECM
main relay turning off is too
early.No fail-safe function. No recovery. ECM malfunction.
3 /
58—
B OFF ECM Main Relay Switched
Off Too LateWhen ignition switch was
turned off, timing of the ECM
main relay turning off is too
late or does not off.No recovery. 1. ECM main relay
m a l f u n c t i o n .
2. ECM malfunction.3 /
58— Flash
CodeCodeSymptom
CodeMILDTC Name DTC Setting Condition Fail-Safe (Back Up) Recovery Condition Related Failure PartsRelated
ECM Pin
No.Related
Multiple
DTC4JA1-TC
(MT)4JH1-TC
(MT)4JH1-TC
(AT)

6E –136 4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS
8 Repair the open circuit between the ECM and MAF
sensor.
Was the problem solved?
— Verify repair Go to Step 13
9 Using the DVM and check the MAF sensor +12V supply circuit.
1. Ignition “On ”, engine “Off ”.
2. Disconnect the MAF & IAT sensor connector.
3. Check the circuit for open circuit.
Was the DVM indicated specified value?
10-14.5V Go to Step 11Go to Step 10
10 Repair the open circuit between the ECM main relay and MAF sensor.
Was the problem solved? —Verify repair Go to Step 11
11 Substitute a known good MAF & IAT sensor assembly and recheck.
Was the problem solved? —Go to Step 12 Go to Step 13
12 Replace the MAF & IAT sensor assembly. Is the action complete? —Verify repair —
13 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 14
14 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
83
4
C-116
C-57(B)
2
V
C-116

6E–188 4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS
Step Action Value(s) Yes No
6Using the DVM and check the wastegate control
solenoid power supply circui t.
1 . I g n i t i o n " O n " , e n g i n e " O f f " .
2. Remove the wastegate control solenoid
connector.
3 . C h e c k t h e c i r c u i t f o r o p e n c i r c u i t .
Was the DVM indicated specified value? 10 - 14.5V Go to Step 8Go to Step 7
7Repair the open circuit between the ECM main relay
and wastegate control solenoid.
Is the action complete? - Verify repair -
8Using the DVM and check the wastegate control
solenoid circuit.
Breaker box is available:
1. Ignition "Off", engine "Off".
2. Install the breaker box as type A. (ECM
disconnected) Ref. Page 6E-103
3. Remove the wattage control solenoid connector.
4. Check the circuit for open or short to ground
circuit.
Was the problem found?
Breaker box is not available:
1. Ignition "Off", engine "Off".
2. Disconnect the ECM connector.
3. Remove the wastegate control solenoid
connector.
4. Check the circuit for open or short to ground
circuit.
Was the problem found?
-Repair faulty
harness and
verify repair Go to Step 11
9Substitute a known good wastegate control solenoid
a n d re ch e c k.
Was the problem solved? - Go to Step 10Go to Step 11
10Replace the wastegate control solenoid.
Is the action complete? - Verify repair -
96
Breaker BoxC-123




C-57C-123