1998 ISUZU TROOPER immobilizer

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±239 ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0563 System Voltage High
Circuit Description
The powertrain control module (PCM) monitors the
system voltage on the ignition feed terminals to the PCM.
A system voltage DTC will set whenever the voltage is
above a calibrated value.
Conditions for Setting the DTC

Ignition ªON.º

System voltage is above 16 volts for 15 minutes.
Action Taken When the DTC Sets

The PCM will not illuminate the malfunction indicator
lamp (MIL).
The PCM will store as Failure Records only conditions
which were present when the DTC was set. This
information will not be stored as Freeze Frame data.
Conditions for Clearing the MIL/DTC

A history DTC P0563 will clear after 40 consecutive
warm-up cycles have occurred without a fault.

DTC P0563 can be cleared by using the Tech 2 ªClear
Infoº function or by disconnecting the PCM battery
feed.
Diagnostic Aids
If the DTC sets when an accessory is operated, check for
a poor connection or excessive current draw.
DTC P0563 ± System Voltage High

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 less than the specified value?
11.5 VGo to Step 3Go to Step 4
31. Charge the battery and clean the battery terminals.
2. Clean the battery ground cable connection if
corrosion is indicated.
Is the battery voltage less than the specified value?
11.5 V
Replace
battery
Go to Step 4
41. Turn ªOFFº all the accessories.
2. Install a Tech 2.
3. Select the ignition voltage parameter on the Tech 2.
4. Start the engine and raise the engine RPM to the
specified value.
Is the voltage more than 2.5 volts greater than the
measurement taken in step 2 or 3?
2000 RPM
Go to
Starting/Char
ging
Go to Step 5
5Replace the PCM.
IMPORTANT:The replacement PCM must be
programmed. Refer to
UBS 98 model year Immobilizer
Workshop Manual.
Is the action complete?ÐVerify repairÐ

6E±240
ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0601 PCM Memory
Circuit Description
The powertrain control module (PCM) used in this vehicle
utilizes an electrically erasable programmable read-only
memory (EEPROM). The EEPROM contains program
information and the calibrations required for engine,
transmission, and powertrain diagnostics operation.
Unlike the PROM used in past applications, the EEPROM
is not replaceable.
Conditions for Setting the DTC

The PCM detects an internal program fault (check sum
error).
Action Taken When the DTC Sets

The PCM will not illuminate the malfunction indicator
lamp (MIL).
The PCM will store conditions which were present
when the DTC was set in the Failure Records data only.
Conditions for Clearing the MIL/DTC

DTC P0601 can be cleared by using the Tech 2 ªClear
Infoº function or by disconnecting the PCM battery
feed.
Diagnostic Aids

DTC P0601 indicates that the contents of the
EEPROM have changed since the PCM was
programmed. The only possible repair is PCM
replacement.
DTC P0601 ± PCM Memory

StepActionValue(s)Ye sNo
1Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
2Replace the PCM.
IMPORTANT:The replacement PCM must be
programmed. Refer to
UBS 98model year Immobilizer
Workshop Manual.
Is the action complete?ÐVerify repairÐ

6E±244
ENGINE DRIVEABILITY AND EMISSIONS
DTC P1154 ± HO2S Transition Time Ratio Bank 2 Sensor 1

 
StepNo Ye s Value(s) Action
21Replace Bank 2 HO2S 1.
Is the action complete?
ÐVerify repairÐ
22Replace the PCM.
IMPORTANT:The replacement PCM must be
programmed. Refer to
UBS 98model year Immobilizer
Workshop Manual.
Is the action complete?ÐVerify repairÐ

6E±248
ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P1380 ABS Rough Road ABS System Fault
Circuit Description
The powertrain control module (PCM) monitors ABS fault
signal. When PCM receives fault signal, PCM will set
DTC P1380.
Conditions for Setting the DTC

Vehicle speed is more than 5 mph.

Load is less than 99%.

Engine revolution is less than 6250 rpm.

PCM receives ABS fault signals from ABS unit.

Ignition on.

Misfire DTCs exist.

100 test failures within 120 test samples.
Action Taken When the DTC Sets

The PCM will store DTC 1380 only, no MIL turn on.
Conditions for Clearing the MIL/DTC

A history DTC P1380 will clear after 40 consecutive
warm-up cycles have occurred without a fault.

DTC 1380 can be cleared by using Tech-2 or
disconnecting the PCM battery feed.
Diagnostic Aids
Check for the following conditions:

PCM and ABS communication line short circuit to other
line may cause faulty signal. Inspect communication
line.

Follow ABS ECU diagnosis procedure, refer to ABS
procedure page.
DTC P1380 ± ABS Rough Road ABS System Fault

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 ªOFFº, review and record
Tech 2 Failure Records Data.
2. Operate the vehicle within Failure Records
conditions as noted.
3. Using a Tech 2, monitor ªSpecific DTCº info for DTC
P1380 and Misfire DTCs until the DTC P1380 and
Misfire DTCs test runs. Note the result.
Does the Tech 2 indicates DTC P1380 and Misfire
DTCs failed this ignition?
Ð
Refer to ABS
diagnosis
After inspect
ABS, unit re-
peat
Step 2
Still problem
exists, go to
Step 3
Clear DTC by
Tech 2
3Check short circuit among communication line of
PCM/ABS and others.
Was short circuit?
Ð
Repair wiring
Verify repair
Go to Step 4
4Replace the PCM.
IMPORTANT:The replacement PCM must be
programmed. Refer to
UBS 98model year Immobilizer
Workshop Manual.
Is the action complete?ÐVerify repairÐ

6E±250
ENGINE DRIVEABILITY AND EMISSIONS
DTC P1404 ± EGR Closed Stuck

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 ªOFFº, review and record
Tech 2 Failure Records Data.
2. Operate the vehicle within Failure Records
conditions as noted.
3. Using a Tech 2, monitor ªDTC inf. for DTC P1404
until the DTC P1404 test runs. Note the result.
Does the Tech 2 indicates DTC P1404 failed this
ignition?
ÐGo to Step 3
Refer to
Diagnostic
Aids
31. Disconnect the EGR valve harness connector.
2. Inspect the EGR valve and connectors for damaged
pin or terminals.
Were there any damaged pins or terminals?
ÐGo to Step 4Go to Step 5
4Repair the damaged pin or terminal.
Is the action complete?
ÐVerify repairÐ
51. Remove EGR valve from Engine.
2. Inspect EGR valve whether there is any excessive
carbon deposit on EGR shaft.
3. Inspect any foreign material inside of EGR valve.
Was excessive carbon deposit on EGR valve shaft
or/and foreign material in EGR valve ?
ÐGo to Step 6Go to Step 7
61. Clean up EGR valve shaft and inside of EGR valve.
2. Remove foreign material from EGR valve.
3. Visually inspect damage of pintle and seat whether
there is bent, leakage may occur.
Was there any severe damage which affects function?
3±6 ohmsGo to Step 8
Verify repair
Go to
Step 7
71. Reconnect.
2. Ignition ªOFFº.
3. Install the Tech 2.
4. Run the engine at idle.
5. On the Tech 2, select F3:Misc. Test F5:EGR.
6. Use the ªUPº arrow to increase the EGR from 0% to
40%.
Did EGR work properly?
ÐÐGo to Step 8
81. Reset the learned zero EGR valve position.
2. Repeat step 7.
Did EGR work properly?
ÐVerify repairGo to Step 9
9Replace the EGR valve.
Replace the EGR valve. Does DTC P1404 still fail
ªspecific DTCº test on the Tech 2?
ÐGo to Step 10Verify repair
10Replace the PCM.
IMPORTANT:The replacement PCM must be
programmed. Refer to
UBS 98model year Immobilizer
Workshop Manual.
Is the action complete?ÐVerify repairÐ

6E±253 ENGINE DRIVEABILITY AND EMISSIONS
DTC P1508 ± IAC System Low RPM

 
StepNo Ye s Value(s) Action
5Visually/physically inspect for following conditions:

Restricted air intake system. Check for a possible
collapsed air intake duct, restricted air filter
element, or foreign objects blocking the air intake
system.

Throttle body. Check for objects blocking the IAC
passage or throttle bore, excessive deposits in
the IAC passage and on the IAC pintle, and
excessive deposits in the throttle bore and on the
throttle plate.
Do any of the above require a repair?
Ð
Refer to
appropriate
section for
on-vehicle
service
Go to Step 6
61. Check for a poor connection at the IAC harness
connector.
2. If a problem is found, replace faulty terminals as
necessary.
Was a problem found?
ÐVerify repairGo to Step 7
7Replace the IAC valve.
Is the action complete?
ÐVerify repairÐ
8Replace the PCM.
IMPORTANT:The replacement PCM must be
programmed. Refer to
UBS 98model year Immobilizer
Workshop Manual.
Is the action complete?ÐVerify repairÐ