sensor ISUZU TROOPER 1998 Service Repair Manual

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±122
4JX1±TC ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0342 (Flash DTC 41)
CMP (Cam Position) Sensor No Signal
060RW133
Circuit Description
The CMP signal produced by the camshaft position
(CMP) sensor pulses when the engine is running and
crankshaft position (CKP) synchro pulses are also being
received. The hall type CMP sensor and the CKP sensor
share 5 V and ground connections at the Engine Control
Module ECM. The third wire at the sensor is a signal
circuit to the ECM. The ECM uses the CMP signal pulses
to initiate sequential fuel injection. If the ECM does not
receive pulses on the CMP reference circuit, DTC P0342
will set.
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 P0342 can be cleared by using the Tech 2 ªClear
Infoº function or by disconnecting the ECM battery
feed.
Diagnostic Aids
An intermittent may be caused by a poor connection,
rubbed-through wire insulation or a wire broken inside the
insulation. Check for:
Poor connection ± Inspect the ECM harness and
connectors for 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, disconnect
the ECM, turn the ignition on and observe a voltmeter
connected to the CMP signal circuit at the ECM
harness connector while moving connectors and
wiring harnesses related to the ICM and the CMP
sensor. A change in voltage will indicate the location
of the fault.
Test Description
Number(s) below refer to the step number(s) on the
Diagnostic Chart.
2. Ensures that the fault is present.
14.Determines whether the fault is being caused by a
missing camshaft magnet or a faulty ECM. The
voltage measured in this step should read around 4
volts, toggling to near 0 volts when the CMP sensor
interfaces with the camshaft magnet.

6E±123 4JX1±TC ENGINE DRIVEABILITY AND EMISSIONS
DTC P0342 ÐCMP Sensor No Signal

StepActionValue(s)Ye sNo
1Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
21. Ignition ªON.º
2. Review and record Tech 2 Failure Records data.
3. Operate the vehicle within Failure Records
conditions as noted.
4. Using a Tech 2, monitor ªSpecific DTCº information
for DTC P0342 until the DTC P0342 test runs.
5. Note test result.
Does the Tech 2 indicate DTC P0342 failed this
ignition?
ÐGo to Step 3
Refer to
Diagnostic
Aids
31. Ignition ªON.º
2. Disconnect the CMP sensor.
3. Measure the voltage between the sensor feed
circuit and the sensor ground circuit at the CMP
sensor harness connector.
Does the voltage measure near the specified value?
4-6 VGo to Step 7Go to Step 4
41. Ignition ªOFF,º disconnect the ECM and the CMP
sensor.
2. Check for poor connections at the camshaft
position sensor.
3. If a problem is found, repair it as necessary.
Was a problem found?
ÐVerify repairGo to Step 5
51. Check for poor connections at the ECM.
2. If a problem is found, repair it as necessary.
Was a problem found?
ÐVerify repair Go to Step 6
61. Check the following circuits between the ECM and
the CMP sensor:

The sensor feed circuit. Open or short to
ground?

The sensor ground circuit. Open or short to
voltage?
2. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repairÐ
71. Ignition ªON,º engine ªOFF.º
2. Measure the voltage between the CMP sensor
signal circuit and the sensor ground circuit at the
CMP sensor harness connector.
Does the voltage measure near the specified value?
4-6 VGo to Step 8Go to Step 9

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±125 4JX1±TC ENGINE DRIVEABILITY AND EMISSIONS
DTC P0342 ÐCMP Sensor No Signal

 
StepNo Ye s Value(s) Action
15Replace the ECM (Refer to the Data Programming in
Case of ECM change).
Is the action complete?
ÐVerify repairÐ
16Replace faulty or missing camshaft magnet.
Is the action complete?
ÐVerify repairÐ

6E±130
4JX1±TC ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P1403 (Flash DTC 32)
EGR EVRV Fault
060RW135
Circuit Description
EGR EVRV Circuit has a common power source in
parallel with EGR, VSV, RPCV, and Intake Throttle Motor.
This may cause multiple DTCs. On such occasion, refer
to ªMultiple ECM Information sensor DTCs Setº.
Diagnostic Aids
Check for the following conditions:

Poor connection or damaged EVRV ± Inspect the
wiring harness for damage.

Ensure EVRV is correctly mounted. See
On-Vehicle
Service.
Reviewing the Failure Records vehicle mileage since the
diagnostic test last failed may help determine how often
the condition that caused the DTC to be set occurs. This
may assist in diagnosing the condition.
Test Description
Number(s) below refer to the step number(s) on the
Diagnostic Chart
3. A malfunctioning MAP sensor can set an EGR DTC.
The MAP sensor could send a constant signal which
is not low enough to set a low MAP DTC. The
constant signal from the MAP sensor also may not
be high enough to set a high MAP DTC. This step
verifies that the MAP sensor is responding.

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±134
4JX1±TC ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0405 (Flash DTC 26)
EGR Pressure Sensor Low 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 P0405 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 P0405 ± EGR Pressure Sensor Low 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 below the specified value?
0.25 VGo to Step 3
Refer to
Diagnostic
Aids
andSymp
tom
Diagnosis

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±136
4JX1±TC ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P1405 (Flash DTC 37)
EGR EVRV Circuit Open/Short
060RW135
Circuit Description
EGR EVRV Circuit has a common power source in
parallel with EGR, VSV, RPCV, and Intake Throttle Motor.
This may cause multiple DTCs. On such occasion, refer
to ªMultiple ECM Information Sensor DTCs Setº.
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 P1405 can be cleared by using the Tech 2 ªClear
Infoº function or by disconnecting the ECM battery
feed.
Diagnostic Aids
An intermittent may be caused by a poor connection,
rubbed-through wire insulation or a wire broken inside the
insulation. Check for:

Poor connection ± Inspect the ECM harness and
connectors for improper mating, broken locks,
improperly formed or damaged terminals, and poor
terminal-to-wire connection.

Damaged harness ± Inspect the wiring harness for
damage.