1998 ISUZU TROOPER Remove engine

6E±105 4JX1±TC ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0204 (Flash DTC 54)
Injector # 4 Circuit Fault
060RW134
Circuit Description
The Engine Control Module ECM has four individual
injector driver circuits. Each controls an injector. When
the driver circuit is grounded by the ECM, the injector is
activated. The ECM monitors the current in each driver
circuit. The voltage on each driver is monitored to detect
a fault. If the voltage is not what the ECM expects to
monitor on the circuit, a DTC is set. This DTC is also set if
an injector driver is shorted to voltage or if there is an open
circuit.
Action Taken When the DTC Sets

The ECM will store conditions which were present
when the DTC was set as Freeze Frame and in the
Failure Records data.
Conditions for Clearing the MIL/DTC

DTC P0204 can be cleared by using the Tech 2 ªClear
Infoº function or by disconnecting the ECM battery
feed.
Diagnostic Aids
An injector driver circuit that is open or shorted to voltage
will cause a DTC P0204 to set.
Test Description
The number(s) below refer to the step number(s) on the
Diagnostic Chart.3. This step determines if DTC P0204 is the result of a
hard failure or an intermittent condition.
Injector Test
This test is conducted to make it sure that appropriate
electric signals are being sent to injectors Nos. 1±4.
Tech±2 must be used for this test.
Test Procedure:
1. Connect Tech±2 to the vehicle DLC.
2. Set Ignition Switch to the ªONº position.
3. Select Control Test.
4. Select Injector Test.
5. Send instructions to each injector (Switch on),
making sure of injector working noise.
NOTE: If injector working noise (Clink) can hardly be
confirmed, remove the engine head cover noise
insulation.
Refer to Section 6A.
6. In the injector whose working noise has been
confirmed, its electric circuit can be regarded as
normal.
As for the injector whose working noise has not
been confirmed, its electric circuit or the injector
proper is faulty.

6E±121 4JX1±TC ENGINE DRIVEABILITY AND EMISSIONS
DTC P0341 ÐCMP Sensor Out of Synchro

 
StepNo Ye s Value(s) Action
101. Check for poor connections at the ECM.
2. If a problem is found, repair it as necessary.
Was a problem found?
ÐVerify repairGo to Step 11
11Backprobe the ECM connector with a DVM to monitor
voltage on the camshaft position input signal circuit
while cranking the engine with the sensor connected.
(Use rubber band, tape, or an assistant to keep the
DVM lead in contact with the sensor terminal during this
test.)
Does the voltage toggle between the specified values?
4-0 VGo to Step 15Go to Step 12
121. Remove the CMP sensor from the engine front
cover (leave the sensor wiring connected).
2. Place a magnet on the CMP sensor.
(If you use a magnet that is too small to cover the face
of the sensor, test on every part of the sensor face
because only a small area will respond to this test.)
Does the DVM display a voltage near the specified
value?
0 VGo to Step 13Go to Step 14
13Replace the faulty or missing camshaft position sensor
magnet.
Is the action complete?
ÐVerify repairÐ
14Replace the camshaft position sensor.
Is the action complete?
ÐVerify repairÐ
15Replace the ECM (Refer to the Data Programming in
Case of ECM change).
Is the action complete?
ÐVerify repairÐ

6E±124
4JX1±TC ENGINE DRIVEABILITY AND EMISSIONS
DTC P0342 ÐCMP Sensor No Signal

 
StepNo Ye s Value(s) Action
81. Turn the ignition ªOFF.º
2. Disconnect the ECM and connect a DVM to monitor
voltage on the camshaft position signal circuit at the
ECM connector.
3. Ignition ªON.º
4. Monitor the voltage display on the DVM while
repeatedly touching the CMP sensor signal circuit
at the CMP sensor connector with a test light to
ground.
Does the DVM voltage display switch between 0 and
approximately 5 volts when the test light is touched to
the CMP sensor signal circuit?
ÐGo to Step 12Go to Step 9
91. Ignition ªOFF.º
2. Leave the ECM disconnected.
3. Ignition ªON.º
4. Probe the camshaft position signal circuit at the
ECM connector with a test light to B+.
5. If the test light is ªON,º locate and repair the short to
ground in the camshaft position input signal circuit.
Was either circuit shorted to ground?
ÐVerify repairGo to Step 10
101. Ignition ªOFF.º
2. Leave the ECM disconnected.
3. Ignition ªON.º
4. Probe the camshaft position signal circuit with a test
light to ground.
5. If the test light is ªON,º locate and repair the short to
voltage in the camshaft position input signal circuit.
Was the test light ªONº?
ÐVerify repairGo to Step 11
111. Ignition ªOFF,º disconnect the ECM (leave the CMP
sensor disconnected).
2. Ignition ªON,º check the following circuit:

The CMP sensor signal circuit for an open.
3. If a problem is found, repair it as necessary.
Was a problem found?
ÐVerify repairÐ
121. Ignition ªON.º
2. Remove the CMP sensor from the engine front
cover (leave the sensor wiring connected).
3. Place a magnet on the CMP sensor. If you use a
magnet that is too small to cover the face of the
sensor, test on every part of the sensor face
because only a small area will respond to this test.
Does the DVM display a voltage near the specified
value?
0 VGo to Step 14Go to Step 13
13Replace the camshaft position sensor.
Is the action complete?
ÐVerify repairÐ
141. Reinstall the CMP sensor to the engine front cover.
2. Observe the DVM connected to monitor voltage on
the camshaft position signal circuit while cranking
the engine.
Does the voltage toggle between the specified values?
4-0 VGo to Step 15Go to Step 16

6E±129 4JX1±TC ENGINE DRIVEABILITY AND EMISSIONS
DTC P0381 ± Glow Lamp Circuit Open/Short

StepActionValue(s)Ye sNo
1Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
21. Review and record Failure Records information.
2. Clear DTC P0381.
3. Observe DTCs.
Is DTC P0381 set?
ÐGo to Step 3
Refer to
Diagnostic
Aid
31. Ignition ªOFF.º
2. Remove the Meter assembly.
3. Check for an open or a short to ground in the Glow
Lamp circuit.
4. If a problem is found, repair as necessary.
(On electric bulb of the Glow Lamp, The Glow Lamp
harness circuit)
Was a problem found?
Ð
Refer to the
Meter in
Electric
section 8
Go to Step 4
4Check the connections at the ECM and replace the
terminals if necessary.
Did any terminals require replacement?
ÐVerify repair Go to Step 5
5Replace the ECM (Refer to the Data Programming in
Case of ECM change).
Is the action complete?
ÐVerify repairÐ

6E±131 4JX1±TC ENGINE DRIVEABILITY AND EMISSIONS
DTC P1403 ± EGR EVRV Fault

StepActionValue(s)Ye sNo
1Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
2Check the EVRV circuit.
Was the EVRV circuit darmage?
Ð
Replace the
EVRV circuit
Go to Step 3
31. Start the engine.
2. Monitor the MAP signal with a scan tool while idling.
3. While idling, jab the accelerator pedal about halfway
down and immediately let the engine return to idle.
Did the MAP value on the scan tool show an immediate
large change?
ÐGo to Step 5Go to Step 4
4Replace the MAP sensor.
Is the action complete?
ÐVerify repairÐ
51. Inspect the exhaust system for modification of
original installed parts or leaks.
2. If a problem was found, repair exhaust system as
necessary.
Was a condition present that required repair?
ÐGo to Step 8Go to Step 6
61. Remove the EGR valve.
2. Visually and physically inspect the pintle, valve
passages and the adapter for excessive deposits or
any kind of a restriction.
3. If a problem is found, clean or replace EGR system
components as necessary.
Was a condition present that required repair?
ÐGo to Step 8Go to Step 7
71. Inspect the EGR passages for a blockage caused
by excessive deposits or other damage.
2. If a problem is found, correct the condition as
necessary.
Was a condition present that required repair?
ÐGo to Step 8
Refer to
Diagnostic
Aids
81. Review and record the scan tool Failure Records
data.
2. Clear DTC and monitor the scan tool System Info
Screen while operating the vehicle as specified in
ªDiagnostic Aids.º
3. Using a scan tool, monitor ªDTCº info for DTC
P1403 until the DTC P1403 test runs.
4. Note the test result.
Does the scan tool indicate DTC P1403 failed this
ignition?
Ð
Go to the last
step
completed in
this
diagnostic
chart
Repair
complete

6E±135 4JX1±TC ENGINE DRIVEABILITY AND EMISSIONS
DTC P0405 ± EGR Pressure Sensor Low Voltage

 
StepNo Ye s Value(s) Action
31. Turn off the ignition switch.
2. Remove the sensor connector connection.
3. Jumper between harness pins ªredº and ªblueº
wires.
4. Turn on the ignition switch ªONº.
Is the EGR pressure sensor voltage reading above the
specified value?
4 VGo to Step 5Go to Step 4
41. Turn off the ignition switch.
2. Remove the jumper wire.
3. Connect the relay & solenoid checker
(5-8840-0386-0) to the battery voltage, then check
the EGR pressure sensor signal circuit (blue wire).
4. Turn on the ignition switch.
Is the value displayed on the Tech 2 above the specified
value?
4 VGo to Step 6Go to Step 7
5Check the terminal connection at the EGR pressure
sensor and repair or replace terminal if necessary.
Is the action complete?
ÐVerify repairÐ
6Repair the 5V power circuit (red) harness or Replace
the ECM (Refer to the Data Programming in Case of
ECM change).
Is the action complete?
ÐVerify repairÐ
7Repair the signal circuit (blue) harness or Replace the
ECM (Refer to the Data Programming in Case of ECM
change).
Is the action complete?
ÐVerify repairÐ

6E±138
4JX1±TC ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0406 (Flash DTC 26)
EGR Pressure Sensor High Voltage
060RW134
Action Taken When the DTC Sets

The ECM will illuminate the malfunction indicator lamp
(MIL) as soon as failure detected.

The ECM will store conditions which were present
when the DTC was set as Freeze Frame and in Failure
Records data.
Conditions for Clearing the MIL/DTC

DTC P0404 can be cleared by using the scan tool
ªClear Infoº function or by disconnecting the ECM
battery feed.
Diagnostic Aids
Check for the following conditions:

Poor connection or damaged harness ± Inspect the
wiring harness for damage.
DTC P0406 ± EGR Pressure Sensor High Voltage

StepActionValue(s)Ye sNo
1Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
2Put the engine into an idling status.
Is the EGR pressure sensor voltage value displayed on
the Tech 2 above the specified value?
4 VGo to Step 3Go to Step 4
31. Turn off the ignition switch.
2. Remove the sensor connector connection.
3. Turn on the ignition switch ªONº.
Is the EGR pressure sensor voltage value displayed on
the Tech 2 below the specified value?
1 VGo to Step 5Go to Step 6

6E±181 4JX1±TC ENGINE DRIVEABILITY AND EMISSIONS
Lack of Power, Sluggish or Spongy Symptom

StepActionValue(s)Ye sNo
1DEFINITION:
Engine delivers less than expected power. Little or no
increase in speed when accelerator pedal is pushed
down part-way.
Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
21. 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?
ÐVerify repairGo to Step 3
3Was a visual/physical check performed?
ÐGo to Step 4
Go to Visual/
Physical
Check
41. Remove and check the air filter element for dirt or
restrictions. Refer to
Air Intake System in
On-Vehicle Service.
2. Replace the air filter element if necessary.
Was a repair required?
ÐVerify repairGo to Step 5
51. Check AP sensor system. Refer to AP sensor
diagnostic
.
2. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repairGo to Step 6
61. Check for water-or alcohol-contaminated fuel.
2. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repairGo to Step 7
71. Using a Tech 2, Injector test.
2. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repairGo to Step 8
81. Check the ECM grounds for the cleanliness,
tightness and proper locations. Refer to the ECM
wiring diagrams in
Electrical Diagnosis.
2. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repairGo to Step 9
91. Check the exhaust system for possible restriction:

Inspect the exhaust system for damaged or
collapsed pipes.

Inspect the muffler for heat distress or possible
internal failure.

Check for a possible plugged catalytic
converter by checking the exhaust system
back pressure. Refer to
Restricted Exhaust
System Check
.
2. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repairGo to Step 10
101. Check the torque converter clutch (TCC) for proper
operation. Refer to
Transmission Diagnosis.
2. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repairGo to Step 11