power ISUZU TF SERIES 2004 Workshop Manual

6E–316 4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS
6 Using the DVM and check the neutral switch (inhibitor switch) power supply circuit.
1. Ignition “On”, engine “Off”.
2. Remove the neutral switch (inhibitor switch) connector from the switch.
3. Check the circuit for open circuit.
Was the DVM indicated specified value?
10-14.5V Go to Step 8Go to Step 7
7 Repair the open circuit between the “ECM fuse (10A)” and neutral switch (between the “Back Up fuse (15A)”
and inhibitor switch).
Is the action complete? — Verify repair —
8 Using the DVM and check the neutral switch (inhibitor switch) circuit.
Breaker box is available:
1. Ignition “Off”, engine “Off”.
2. Install the breaker box as type B. (ECM connected) Ref. Page 6E-104
3. Ignition “On”, engine “Off”.
4. Check the circuit for open or short to voltage circuit.
Was the DVM indicated specified value?
Breaker box is not available: 1. Ignition “On”, engine “Off”.
2. Back probe the DVM to the neutral switch (inhibitor switch) and check the circuit for open or
short to voltage circuit.
Was the DVM indicated specified value?
Neutral (P or
N): 10-14.5V Other than
neutral (P or
N): Less than
1V Go to Step 11 Fix ed at 10-
14.5V: Go to Step 9
Fix ed at less
than 1V: Go to
Step 10
Step Action Value(s) Yes No
V
E-12
M/T
V
3
E-51
A/T
E-687Br eak er Box




V
8
2
VV
E-11
E-51
M/T
A/T

6E–326 4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS
6 Using the DVM and check the “CHECK ENGINE”
lamp circuit.
1. Ignition “Off”, engine “Off”.
2. Disconnect the meter connector and immobilizer
control unit connector.
3. Ignition “On”.
4. Check the circuit for short to power supply circuit.
Was DVM indicated specified value?
Less than 1V Go to Step 7Repair faulty
harness and
verify repair Step Action Value(s) Yes No
7
V
B-68

6E–328 4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS
8 Using the DVM and check the ECM and immobilizer
control unit communication circuit.
1. Ignition “Off”, engine “Off”.
2. Disconnect the immobilizer control unit connector.
3. Ignition “On”.
4. Check the circuit for short to power supply circuit.
Was the DVM indicated specified value?
Less than 1V Go to Step 9Repair faulty
harness and
verify repair
9 Using the DVM and check the ECM and immobilizer
control unit communication 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. Disconnect the immobilizer control unit 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 the immobilizer control unit
connector and ECM connector.
3. Check the circuit for open or short to ground
circuit.
Was the problem found?
—Repair faulty
harness and
verify repair Go to Step 10 Step Action Value(s) Yes No
8
V
B-68
B-6835Breaker Box





35
8
C-56
B-68

6E–332 4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS
6 Using the DVM and check the “CHECK ENGINE”
lamp circuit.
1. Ignition “Off”, engine “Off”.
2. Disconnect the meter connector and immobilizer
control unit connector.
3. Ignition “On”.
4. Check the circuit for short to power supply circuit.
Was DVM indicated specified value?
Less than 1V Go to Step 7Repair faulty
harness and
verify repair Step Action Value(s) Yes No
7
V
B-68

4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS 6E–333
7 Using the DVM and check the “CHECK ENGINE”
lamp 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. Disconnect the immobilizer control unit 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 the immobilizer control unit
connector and ECM connector.
3. Check the circuit for open or short to ground
circuit.
Was the problem found?
—Repair faulty
harness and
verify repair Go to Step 8
8 Using the DVM and check the ECM and immobilizer
control unit communication circuit.
1. Ignition “Off”, engine “Off”.
2. Disconnect the immobilizer control unit connector.
3. Ignition “On”.
4. Check the circuit for short to power supply circuit.
Was the DVM indicated specified value?
Less than 1V Go to Step 9Repair faulty
harness and
verify repair Step Action Value(s) Yes No
B-6 842Breaker Box





42
7
C-56
B-68
8
V
B-68

4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS 6E–345
8 Using the DVM and check the CAN low 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. Disconnect the PSG (pump control unit)
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 PSG (pump control unit)
connector.
3. 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 CAN high circuit.
1. Ignition “On”, engine “Off”.
2. Disconnect the PSG (pump control unit)
connector.
3. Check the circuit for short to power supply circuit.
Was the DVM indicated battery voltage or
approximately 5V?
—Go to Step 10Go to Step 11 Step Action Value(s) Yes No
E-699Breaker Box





991 C-57 E-6
2
V
E-6

6E–346 4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS
10 Repair the short to voltage circuit between the ECM
and PSG (pump control unit).
Is the action complete?
—Verify repair—
11 Using the DVM and check the CAN low circuit.
1. Ignition “On”, engine “Off”.
2. Disconnect the PSG (pump control unit)
connector.
3. Check the circuit for short to power supply circuit.
Was the DVM indicated battery voltage or
approximately 5V?
—Go to Step 12Go to Step 13
12 Repair the short to voltage circuit between the ECM
and PSG (pump control unit).
Is the action complete?
—Verify repair—
13 Using the DVM and check the PSG (pump control
unit) ground circuit.
1. Ignition “Off”, engine “Off”.
2. Disconnect the PSG (pump control unit)
connector.
3. Check the circuit for open circuit.
Was the problem found?
—Repair faulty
harness and
verify repair Go to Step 14 Step Action Value(s) Yes No
1002 C-57 E-6
1
V
E-6
991 C-57 E-6
6
E-6

4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS 6E–353
9 Using the DVM and check the CAN low 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. Disconnect the PSG (pump control unit)
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 PSG (pump control unit)
connector.
3. Check the circuit for open or short to ground
circuit.
Was the problem found?
—Repair faulty
harness and
verify repair Go to Step 10
10 Using the DVM and check the CAN high circuit.
1. Ignition “On”, engine “Off”.
2. Disconnect the PSG (pump control unit)
connector.
3. Check the circuit for short to power supply circuit.
Was the DVM indicated battery voltage or
approximately 5V?
—Go to Step 11 Go to Step 12 Step Action Value(s) Yes No
E-699Breaker Box




991 C-57 E-6
2
V
E-6

6E–354 4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS
11 Repair the short to voltage circuit between the ECM
and PSG (pump control unit).
Is the action complete?
—Verify repair—
12 Using the DVM and check the CAN low circuit.
1. Ignition “On”, engine “Off”.
2. Disconnect the PSG (pump control unit)
connector.
3. Check the circuit for short to power supply circuit.
Was the DVM indicated battery voltage or
approximately 5V?
—Go to Step 13Go to Step 14
13 Repair the short to voltage circuit between the ECM
and PSG (pump control unit).
Is the action complete?
—Verify repair—
14 Using the DVM and check the PSG (pump control
unit) ground circuit.
1. Ignition “Off”, engine “Off”.
2. Disconnect the PSG (pump control unit)
connector.
3. Check the circuit for open circuit.
Was the problem found?
—Repair faulty
harness and
verify repair Go to Step 15 Step Action Value(s) Yes No
1002 C-57 E-6
1
V
E-6
991 C-57 E-6
6
E-6

4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS 6E–377
SURGES AND/OR CHUGS SYMPTOM
DEFINITIONS: Engine power variation under steady
throttle or cruise. Feels like the vehicle speeds up and
slows down with no charge in the accelerator pedal.
time rpm
Su rge
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. Perform a bulletin search.
2. If a bulletin that addresses the symptom is found,
correct the condition as instructed in the bulletin.
Was a bulletin found that addresses the symptom?—Verify repair Go to Step 3
3 Was a visually/physical check performed?
—Go to Step 4Go to Visual /
physical Check
4 Is the customer using the incorrect fuel type? Diesel fuel
onlyReplace with
diesel fuel Go to Step 5
5 Visually/physically inspect for the following conditions.
Restrict air intake system. Check for a restricted air
filter element, or foreign objects blocking the air
intake system
Check for objects blocking or ex cessive deposits in
the throttle bore and on the throttle plate
Check for a condition that causes a large vacuum
leak, such as an incorrectly installed or faulty
crankcase ventilation hose.
Restrict air intake system at the turbocharger.
Check for objects blocking the turbocharger
compressor wheel or turbine shaft sticking.
If a problem is found, repair as necessary.
Was a problem found?—Verify repair Go to Step 6
6 Check the ECM & PSG grounds to verify that they are
clean and tight. Refer to the ECM wiring diagrams.
Was a problem found?—Verify repair Go to Step 7
7 1. Using the Tech 2, ignition “On” and engine “Run”.
2. Monitor the “A/C Information Switch” in the data
display.
Does the Tech 2 indicate correct “A/C Information
Switch” status depending on A/C switch position?
If a problem is found, repair as necessary.
Was the problem found?—Verify repair Go to Step 8