check engine light ISUZU TROOPER 1998 Service Manual PDF

6E±186
ENGINE DRIVEABILITY AND EMISSIONS
If the test light blinks while cranking, the PCM and
the wiring to the injectors are OK. The Fuel Injector
Coil Test Procedure will check if the injectors are
faulty.
R321059
7. Because the test light was ªONº steady, voltage to
the injector is OK, but the driver circuit is grounded
at all times. This step determines if the circuit is
shorted to ground or the PCM is faulty.
9. The reading should be about 12-14
.
10.Locating the open in the harness or in the injector
will require removal of the manifold to provide
access.
DTC P0206 ± Injector 6 Control Circuit

StepActionValue(s)Ye sNo
1Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
2Will the engine start?
ÐGo to Step 3
Go to Engine
Cranks But
Will Not Run
chart
31. Install the Tech 2. Clear the DTC.
2. Idle the engine for one minute.
Does DTC P0206 reset?
ÐGo to Step 5Go to Step 4
41. Review the Freeze Frame data with the ignition
ªONº and the engine ªOFFº and note the
parameters.
2. Operate the vehicle within the Freeze Frame
conditions as noted.
Does P0206 reset?
ÐGo to Step 5
Go to
Diagnostic
Aids
51. Engine ªOFF.º
2. Disconnect the injector test connector.
3. Install an injector test light 5-8840-2636-0 on
injector connector.
4. Crank the engine and note the light.
Does the cylinder 6 test light blink?
Ð
Go to Fuel
Injector Coil
Test
Procedure
Go to Step 6
6Note whether the injector test light for cylinder 6 was
ªOFFº or ªONº steady in step 5.
Was the test light ªONº steady while cranking the
engine?
ÐGo to Step 7Go to Step 9

6E±187 ENGINE DRIVEABILITY AND EMISSIONS
DTC P0206 ± Injector 6 Control Circuit

 
StepNo Ye s Value(s) Action
71. Disconnect the PCM connector for the affected
injectors.
2. With a test light connected to B+, probe the affected
injector driver circuit.
Does the test light illuminate?
ÐGo to Step 8Go to Step 15
8Repair short to ground in the injector driver circuit.
Is the action complete?
Ð
Go to OBD
System
Check
Ð
91. Disconnect the injector test connector.
2. At the injector side of the harness, connect an
ohmmeter between the positive wire (red with blue
tracer) and the wire for cylinder 6 (green with yellow
tracer).
Does the ohmmeter indicate continuity?
ÐGo to Step 11Go to Step 10
10Repair the open injector harness wire or open injector
Is the action complete?
ÐVerify repairÐ
11At the PCM side of the injector test connector, check
the green/yellow wire for a short to voltage.
Was there a short to voltage?
ÐGo to Step 12Go to Step 13
12Repair the short to voltage.
Is the action complete?
ÐVerify repairÐ
13Check for an open circuit between the injector test
connector and the PCM.
Was there an open circuit?
ÐGo to Step 14Go to Step 15
14Repair the open circuit.
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±191 ENGINE DRIVEABILITY AND EMISSIONS
DTC P0327 ± KS Sensor Circuit

StepActionValue(s)Ye sNo
1Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
2IMPORTANT:If an engine knock can be heard, repair
the engine mechanical problem before proceeding with
this diagnostic.
1. Operate the engine within the conditions specified
in diagnostic support ªConditions for Setting the
DTC.º
2. Using Tech 2, monitor ªSpecific DTCº info for DTC
P0327 until the DTC P0327 test runs.
3. Note the test result.
Does Tech 2 indicate DTC P0327 failed this ignition?
ÐGo to Step 4Go to Step 3
31. Ignition ªON,º engine ªOFF.º
2. Review and record Tech 2 Failure Records data.
3. Operate the vehicle within Failure Records
conditions.
4. Using Tech 2, monitor ªSpecific DTCº info for DTC
P0327 until the DTC P0327 test runs.
5. Note the test result.
Does Tech 2 indicate DTC P0327 failed this ignition?
ÐGo to Step 4
Refer to
Diagnostic
Aids
41. Check for a damaged terminal at the knock sensor
connector.
2. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repairGo to Step 5
5Using a test light to battery +, check the black/blue wire
(PCM side) to verify that the shield connection is good.
Did the test light illuminate?
ÐGo to Step 7Go to Step 6
6Repair the open shield ground.
Is the action complete?
ÐVerify repairÐ
71. Ignition ªOFF,º disconnect the PCM.
2. Check the KS signal circuit for a poor terminal
connection at the PCM.
3. If a problem is found, replace the faulty terminal.
Was a problem found?
ÐVerify repairGo to Step 8
81. Ignition ªOFF,º PCM disconnected.
2. Check the KS signal circuit between the PCM and
the knock sensor connector for an open, a short to
voltage, or a short to ground.
3. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repairGo to Step 9
91. Ignition ªOFF,º PCM disconnected.
2. Knock sensor connected.
3. Measure the resistance of the knock sensor by
connecting the DVM between the PCM connector
and the engine block.
Is the resistance of each knock sensor near the
specified value?
100K ohmsGo to Step 10Go to Step 11

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±226
ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0404 EGR Open Stuck
D06RW106
Circuit Description
The powertrain control module (PCM) monitors the EGR
valve pintle position input to ensure that the valve
responds properly to commands from the PCM, and to
detect a fault if pintle position is different from
commanded position. If the PCM detects a pintle position
signal indicates more than 15 points different between
current and commanded and more than 15 seconds, the
PCM will set DTC P0404.
Conditions for Setting the DTC

Ignition voltage is between 11 and 16 volts.

Intake Air temp is more than 3
C.

Desire EGR position is more than 0.

The difference between desired EGR and current EGR
is less than 3%.

Difference EGR pintle position between current and
commanded position becomes more than 15% and
last more than 15 seconds, and this condition meets
three times in a trip. Then it trigger, the PCM lights on.
Action Taken When the DTC Sets

The PCM will illuminate the malfunction indicator lamp
(MIL) as soon as failure detected after consecutive 2nd
trip in which the fault is detected.
The PCM 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 Tech 2 ªClear Infoº
function or by disconnecting the PCM battery feed.
Diagnostic Aids
Check for the following conditions:

Excessive carbon deposit on EGR valve shaft may
cause EGR stuck open or unsmooth operation. Those
carbon deposit may occur by unusual port operation.
Clean up carbon may make smooth function of EGR
valve.

Poor connection or damaged harness ± Inspect the
wiring harness for damage. If the harness appears to
be OK, observe the EGR actual position display on
Tech 2 while moving connectors and wiring harnesses
related to EGR valve. A change in the display will
indicate the location of the fault.

6E±235 ENGINE DRIVEABILITY AND EMISSIONS
DTC P0502 ± VSS Circuit Low Input

StepActionValue(s)Ye sNo
1Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
2Does the speedometer work?ÐGo to Step 10Go to Step 3
31. Disconnect the VSS connector.
2. Ignition ªON.º
3. Using a test light to battery +, probe the connector
ground wire.
Did the light illuminate?
ÐGo to Step 5Go to Step 4
4Repair the sensor ground.
Is the action complete?
ÐVerify repairÐ
51. Ignition ªON,º sensor disconnected.
2. Using a DVM, measure at the VSS connector
between ground and voltage supply.
Was the measurement near the specified value?
Battery
voltage
Go to Step 7Go to Step 6
6Repair the open or short to ground which may have
blown the meter fuse.
Is the action complete?
ÐVerify repairÐ
71. Ignition ªON,º VSS disconnected.
2. Using a DVM, measure at the VSS connector
between ground and the wire from the
speedometer.
Was the measurement near the specified value?
7.5-8 VGo to Step 9Go to Step 8
8Check for an open or short circuit between the
speedometer and the VSS.
Was an open or short circuit located?
ÐVerify repairGo to Step 9
9Replace the speedometer.
Is the action complete?
ÐVerify repairÐ

6E±236
ENGINE DRIVEABILITY AND EMISSIONS
DTC P0502 ± VSS Circuit Low Input

 
StepNo Ye s Value(s) Action
101. Ignition ªOFF.º
2. Disconnect the MAF sensor and remove the air
cleaner assembly and filter element to gain access
to the 16-way black connector located immediately
to the rear of the left front headlamp. The connector
attaches the VSS wires from the transmission
harness to the left-side engine harness.
3. Disconnect the black 16-way connector.
4. Select a terminal adapter from kit J 35616 that can
be used with a jumper to supply B+ to the blue wire
with a yellow tracer (transmission side of the
connector).
5. Use another terminal adapter to attach a voltmeter
to the light-green wire with a while tracer (next to the
wire in the previous step.)
6. Disconnect the blue connector next to the black
16-way connector, and locate the black/red tracer
wire at one corner of the blue connector. The
black/red wire is the VSS ground. Use a terminal
adapter to attach a jumper to ground to the
black/red VSS ground wire at the transmission side
of the blue connector.
7. Raise the rear wheels off the ground with
transmission in neutral.
Does the DVM toggle back and forth between 0.6 V and
10 V as the wheels (and driveshaft) are rotated?
ÐGo to Step 11Go to Step 12
11Replace the VSS.
Is the action complete?
ÐVerify repairÐ
12Check for an open or short between the PCM and the
speedometer.
Was a problem found?
ÐVerify repairGo to Step 13
13Replace the PCM.
IMPORTANT:The replacement PCM must be
programmed. Refer to
UBS 98model year Immobilizer
Workshop Manual.
Is the action complete?ÐVerify repairÐ

6E±238
ENGINE DRIVEABILITY AND EMISSIONS
DTC P0562 ± System Voltage Low

StepActionValue(s)Ye sNo
1Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
2Using a Tech 2, measure the battery voltage at the
battery.
Is the battery voltage greater than the specified value?
11.5 VGo to Step 3
Charge
battery, then
go to
Step 3
31. Using a Tech 2.
2. Select ªIgnition Voltsº on the Tech 2.
3. Start the engine and raise the engine speed to the
specified value.
4. Load the electrical system by turning on the
headlights, high blower, etc.
Is the ignition voltage approximately equal to the
specified value?
2000 RPM
12.8-14.1 V
Go to Step 4
Go to
Starting/Char
ging
41. Ignition ªOFF.º
2. Disconnect the PCM connector at the PCM.
3. Using a DVM, measure the battery voltage at the
PCM connector A-4.
Is it approximately equal to battery voltage?
Ð
Check for
excessive
current draw
with ignition
ªOFF,º engine
ªOFF.º
Go to Step 5
51. Check for faulty connections at the PCM harness
terminals.
2. Repair as necessary.
Was a repair necessary?
ÐVerify repairGo to Step 6
6Check for an open battery feed circuit to the PCM.
Is the action complete?
ÐVerify repairGo to Step 7
7Replace the PCM.
IMPORTANT:The replacement PCM must be
programmed. Refer to
UBS 98model year Immobilizer
Workshop Manual.
Is the action complete?ÐVerify repairÐ

6E±249 ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P1404 EGR Closed Stuck
D06RW106
Circuit Description
The powertrain control module (PCM) monitors the EGR
valve pintle position input to ensure that the valve
responds properly to commands from the PCM, and to
detect a fault if current pintle zero position is different from
the learned zero position. If the PCM detects a pintle
position signal indicates more than 30 % different
between current zero position and the learned zero
position and more than 5 seconds, and this condition
meet 3 times during trip, then the PCM will set DTC
P1404.
Conditions for Setting the DTC

Ignition voltage is between 11 and 16 volts.

Intake Air temp is more than 3
C.

Desire EGR position is 0.

Difference EGR pintle position between current and
the learned zero is more than 30 % last more than 5
seconds, and meet three time to the above condition
during a trip. Then it trigger the PCM lights on.
Action Taken When the DTC Sets

The PCM will illuminate the malfunction indicator lamp
(MIL) after consecutive 2nd trip in which the fault is
detected.
The PCM 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 P1404 can be cleared by using the Tech 2 ªClear
Infoº function or by disconnecting the PCM battery
feed.
Diagnostic Aids
Check for the following conditions:

Excessive carbon deposit on EGR valve shaft or/and
foreign material may cause no return to EGR valve
fully seated. Those carbon deposit may occur by
unusual port operation. Remove foreign material
or/and excessive carbon deposit on EGR valve shaft
may make return to EGR valve fully seated.

Poor connection or damaged harness ± Inspect the
wiring harness for damage. Same as P1406
description
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.

6E±252
ENGINE DRIVEABILITY AND EMISSIONS
passage and on the IAC pintle, and excessive deposits
in the throttle bore and on the throttle plate.

Large vacuum leak ± Check for a condition that causes
a large vacuum leak, such as an incorrectly installed or
faulty PCV valve or a disconnected brake booster
hose.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 P1508 ± IAC System Low RPM

StepActionValue(s)Ye sNo
1Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
21. Start the engine.
2. Turn all accessories ªOFFº(A/C, rear defroster,
etc).
3. Using a Tech 2, command RPM up to 1500, down to
500, and the up to 1500 while monitoring the
ªEngine Speedº on the Tech 2.
NOTE: This Tech 2 command may cause the engine to
ªcut outº when RPM goes above 1500. If this occurs,
the ªcutting outº will stop when the Tech 2 command for
the test is discontinued, or if the Tech 2 command is
changed to less than 1500 RPM.
Does the ªEngine Speedº remain within the specified
value of the ªDesired Idleº for each RPM command?
+ 50 RPM
No trouble
found. Go to
Diagnostic
Aids
Go to Step 3
31. Disconnect the IAC.
2. Install IAC Node Light 5-8840-2312-0 or equivalent.
3. With the engine running, command RPM up to
1500, down to 500, and then up to 1500 while
observing the node light.
NOTE: This Tech 2 command may cause the engine to
ªcut outº when RPM goes above 1500. If this occurs,
the ªcutting outº will stop when the Tech 2 command for
the test is discontinued, or if the Tech 2 command is
changed to less than 1500 RPM.
Does each node light cycle red and green (never
ªOFFº)?
ÐGo to Step 5Go to Step 4
41. Check the following circuits for an open, short to
voltage, short ground, or poor connections at the
PCM:

IAC ªAº Low.

IAC ªAº High.

IAC ªBº Low.

IAC ªBº High.
2. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repairGo to Step 8