1998 ISUZU TROOPER check engine

6E±199 ENGINE DRIVEABILITY AND EMISSIONS
Conditions for Clearing the MIL/DTC

DTC P0341 can be cleared by using Tech 2 ªClear Infoº
function or by disconnecting the PCM 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 PCM 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 PCM, turn the ignition on and observe a voltmeter
connected to the CMP signal circuit at the PCM
harness connector while moving connectors andwiring harnesses related to the ICM and the CMP
sensor. A change in voltage will indicate the location
of the fault.
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.
2. Ensures that the fault is present.
12.Determines whether the fault is being caused by a
missing camshaft magnet or a faulty sensor. 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±200
ENGINE DRIVEABILITY AND EMISSIONS
DTC P0341 ± CMP Sensor Circuit Performance

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 Tech 2, monitor ªSpecific DTCº info for DTC
P0341 until the DTC P0341 test runs.
5. Note the test result.
Does Tech 2 indicate DTC P0341 failed this ignition?
ÐGo to Step 3
Refer to
Diagnostic
Aids
31. Disconnect the CMP sensor.
2. 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 4Go to Step 5
4Measure 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 11Go to Step 8
5If the voltage measured in step 3 was less than 4-6
volts, proceed directly to step 6 without completing this
step.
If the voltage in step 3 was greater than 4-6 V, repair the
short to voltage in the CMP feed circuit.
Is the action complete?
ÐVerify repairÐ
61. Check for poor connections at the camshaft
position sensor.
2. If a problem is found, repair it as necessary.
Was a problem found?
ÐVerify repairGo to Step 7
71. Ignition ªOFF,º disconnect the PCM and the CMP
sensor.
2. Check the following circuits for an open between the
ignition coil and the CMP sensor:

The sensor feed circuit.
3. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repair Go to Step 9
81. Ignition ªOFF,º disconnect the PCM (leave the CMP
sensor disconnected).
2. Ignition ªON,º check the following circuits:

The CMP sensor signal circuit for an open or a
short to voltage.

The CMP sensor input signal circuit for a short
to ground.
3. If a problem is found, repair it as necessary.
Was a problem found?
ÐVerify repairGo to Step 9
9Check for a short or open in the sensor ground circuit.
Was a problem found?
ÐVerify repairGo to Step 10

6E±201 ENGINE DRIVEABILITY AND EMISSIONS
DTC P0341 ± CMP Sensor Circuit Performance

 
StepNo Ye s Value(s) Action
101. Check for poor connections at the PCM.
2. If a problem is found, repair it as necessary.
Was a problem found?
ÐVerify repairGo to Step 11
11Backprobe the PCM 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 PCM.
IMPORTANT:The replacement PCM must be
programmed. Refer to
UBS 98model year Immobilizer
Workshop Manual.
Is the action complete?ÐVerify repairÐ

6E±203 ENGINE DRIVEABILITY AND EMISSIONS
Conditions for Clearing the MIL/DTC

DTC P0342 can be cleared by using Tech 2 ªClear Infoº
function or by disconnecting the PCM 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 PCM 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 PCM, turn the ignition on and observe a voltmeterconnected to the CMP signal circuit at the PCM
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 PCM. 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.
DTC P0342 ± CMP Sensor Circuit Low

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 Tech 2, monitor ªSpecific DTCº information
for DTC P0342 until the DTC P0342 test runs.
5. Note test result.
Does 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 PCM 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 PCM.
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 PCM 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

6E±204
ENGINE DRIVEABILITY AND EMISSIONS
DTC P0342 ± CMP Sensor Circuit Low

 
StepNo Ye s Value(s) Action
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
81. Turn the ignition ªOFF.º
2. Disconnect the PCM and connect a DVM to monitor
voltage on the camshaft position signal circuit at the
PCM 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 PCM disconnected.
3. Ignition ªON.º
4. Probe the camshaft position signal circuit at the
PCM 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 PCM 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 PCM (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

6E±206
ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0351 Ignition 1 Control Circuit
D06RW072
Circuit Description
The powertrain control module's (PCM) control circuit 1
provides a zero-volt or a 5-volt output signal to the ignition
coil. The normal voltage on the circuit is zero volts. When
the ignition coil receives the 5-volt signal from the PCM, it
provides a ground path for the B+ supply to the primary
side of the number 1 ignition coil. When the PCM shuts off
the 5 volts to the ignition coil, the ignition coil turns ªOFF.º
This causes the ignition coil primary magnetic field to
collapse, producing a voltage in the secondary coil which
fires the spark plug.
The circuit between the PCM and ignition coil is monitored
for an open circuit, short to voltage, and short to ground.
When the PCM detects a problem on ignition control
circuit 1, it will set a DTC P0351.
Conditions for Setting the DTC

The ignition is ªON.º

The engine is turning, determined by the 58X
crankshaft position input signal.
The output voltage is not equal to 5 volts when output
is ªON.º

The output voltage is not equal to 0 volts when output
is ªOFF.º

Twenty test failures occur within 40 samples of
continuous spark events.
Action Taken When the DTC Sets

The PCM will illuminate the malfunction indicator lamp
(MIL) the first time the fault is detected.

The PCM 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 P0351 can be cleared by using Tech 2 ªClear Infoº
function or by disconnecting the PCM battery feed.
Diagnostic Aids
Check for the following conditions:

6E±207 ENGINE DRIVEABILITY AND EMISSIONS

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

Damaged harness ± Inspect the wiring harness for
damage. If the harness appears to be OK, observe
Tech 2 display related to DTC P0351 while moving theconnector and wiring related to the ignition system. A
change in the display will indicate the location of the
fault.
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.
DTC P0351 ± Ignition 1 Control Circuit

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 engine ªOFF.º
2. Review and record Tech 2 Failure Records data.
3. Operate the vehicle within Failure Record
conditions as noted.
4. Use Tech 2 to monitor the ªSpecific DTCº
information for DTC P0351 until the DTC P0351 test
runs.
5. Note the test result.
Does Tech 2 indicate DTC P0351 failed this ignition
cycle?
ÐGo to Step 3
Go to
Diagnostic
Aids
3Check for faulty connection at ignition coil.
Was a problem found?
ÐVerify repair Go to Step 4
4Check for faulty connection at PCM connector.
Was a problem found?
ÐVerify repair Go to Step 5
51. Ignition ªON,º engine ªOFF.º
2. Back probe the ignition control circuit 1 at the PCM
with a DVM.
Is the voltage near the specified value?
25-55 mVGo to Step 6Go to Step 9
61. Ignition ªON,º engine running.
2. Back probe the ignition control circuit at the PCM for
the cylinder being tested.
Is the voltage in the specified range, rapidly toggling
back and forth to a reading 20-50 mV higher?
100-180 mVGo to Step 7Go to Step 13
71. Ignition ªOFF.º
2. Disconnect the 3-pin and 5-pin connectors at the
ignition coil.
3. Check ignition control circuit 1 voltage at the ignition
coil connector while cranking the engine.
Does the voltage measure between the specified
values?
200-1200 mVGo to Step 8Go to Step 11
8Replace the ignition coil.
Is the action complete?
ÐVerify repairÐ
91. Ignition ªOFF.º
2. Disconnect the PCM and the ignition coil.
3. Check ignition control circuit 1 for short to ground.
Was a problem found?
ÐVerify repair Go to Step 10
10Check ignition control circuit 1 for short to voltage.
Was a problem found?
ÐVerify repairGo to Step 13

6E±208
ENGINE DRIVEABILITY AND EMISSIONS
DTC P0351 ± Ignition 1 Control Circuit

 
StepNo Ye s Value(s) Action
11Check for an open ignition control circuit 1.
Was the ignition control circuit open?
ÐGo to Step 12Go to Step 13
12Repair the open ignition control circuit.
Is the action complete?
ÐVerify repairÐ
13Replace the PCM.
IMPORTANT:The replacement PCM must be
programmed. Refer to
UBS 98model year Immobilizer
Workshop Manual.
Is the action complete?ÐVerify repairÐ