2002 ISUZU AXIOM transmission

6E±299
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0401 EGR Flow Insufficient
060R200050
Circuit Description
The powertrain control module (PCM) tests the exhaust
gas recirculation (EGR) system during deceleration by
momentarily commanding the EGR valve to open while
monitoring the manifold absolute pressure (MAP) sensor
signal. When the EGR valve is opened, the PCM
monitors the change in MAP input signal. The PCM
compares the MAP change to a RPM vs. BARO table.
When the PCM interprets the change in MAP to be out of
limits, the PCM will set DTC P0401. The number of test
samples required to accomplish this may vary according
to the severity of the detected flow error.
Normally, the PCM will only allow one EGR flow test
sample to be taken during an ignition cycle. To aid in
verifying a repair, the PCM allows twelve test samples
during the first ignition cycle following a Tech 2 ªClear Infoº
or a battery disconnect. Between nine and twelve
samples should be sufficient for the PCM to determine
adequate EGR flow and pass the EGR test.
Conditions for Setting the DTC

No TP sensor, vehicle speed sensor (VSS), MAP
sensor, IAT sensor, IAC, EGR Pintle Position sensor,
ECT sensor, misfire, or automatic transmission DTCs
set.

Engine coolant temperature is greater than 60
C
(140
F).

Ignition voltage between 11.5 and 16 volts.

Vehicle speed is greater than 24 km/h (15 mph).
A/C clutch status is unchanged.

TCC status is unchanged.
Start Test

TP angle is less than 0.8%.

EGR duty cycle is less than 1%.

MAP is steady, changing less than 2 kPa.

Engine speed is between 1100 RPM and 2000 RPM
(M/T).

MAP between 10 kPa and 40 kPa.

Engine speed is between 900 RPM and 1500 rpm
(A/T).
The test will be aborted if the vehicle speed changes
by more than 16 km/h (10 mph), engine speed
changes by more than 100 RPM or the EGR is
opened less than 95% of commanded position.

The PCM will only run the EGR test during a closed
throttle condition.

The PCM will only run the EGR test at vehicle speeds
above 24 km/h (15 mph).

Several deceleration cycles will be necessary to run a
sufficient number of EGR flow tests.
Action Taken When the DTC Sets

The PCM will ON the MIL after second trip with
detected fault.

6E±353
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0502 VSS Circuit Low Input
060R200056
Circuit Description
The vehicle speed sensor has a magnet rotated by the
transmission output shaft. Attached to the sensor is a hall
effect circuit the interacts with the magnetic field treated
by the rotating magnet. A 12-volt operating supply for the
speed sensor hall circuit is supplied from the meter fuse.
The VSS pulses to ground the 9-volt signal sent from the
powertrain control module (PCM) on the reference circuit.
The PCM interprets vehicle speed by the number of
pulses to ground per second on the reference circuit.
Conditions for Setting the DTC

Engine is running.

Engine speed is between 1800 RPM and 2500 RPM.

Throttle angle is between 10% and 40%.

Engine load is greater than 50 kPa.

PCM detects no VSS signal for 12.5 seconds over a
period of 15 seconds.
Action Taken When the DTC Sets

The PCM will ON the MIL after second trip with
detected the fault.

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

The PCM will turn the MIL ªOFFº on the third
consecutive trip cycle during which the diagnostic has
been run and the fault condition is no longer present.

A history DTC P0502 will clear after 40 consecutive
warm-up cycles have occurred without a fault.

DTC P0502 can be cleared by using the Tech 2 ªClear
Infoº function or by disconnecting the PCM battery
feed.
Test Description
Number(s) below refer to the step number(s) on the
Diagnostic Chart.
10. To avoid backprobing the VSS and possibly
damaging a seal or terminal, the VSS output can be
tested at the point where the transmission harness
connects to the engine harness. Power and ground
are applied by jumpers to the VSS through the
connectors which are located to the rear of the air
cleaner assembly. The VSS signal is monitored
with a DVM as the rear driveshaft turns. The
wheels can be turned to rotate the driveshaft, or in
2-wheels-drive vehicles the driveshaft can be turned
directly.

6E±355
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
DTC P0502 ± VSS Circuit Low Input

 
StepNo Ye s Value(s) Action
101. Ignition ªOFFº.
2. Disconnect the MAF sensor. 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 white 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
On-Vehicle Service in
Powertrain Control Module and Sensors for
procedures.
ANd also refer to latest Service Bulletin.
Check to see if the Latest software is released or not.
And then Down Load the LATEST PROGRAMMED
SOFTWARE to the replacement PCM.
Is the action complete?
ÐVerify repairÐ

6E±376
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0601 PCM Memory
060RY014
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. When the PCM is replaced or a
calibration update is required, the PCM must be
programmed using a Tech 2. Refer to
On-Vehicle Service
in Powertrain Control Module and Sensors for the
EEPROM programming procedure.
Conditions for Setting the DTC

The PCM detects an internal program fault (check sum
error).
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

The PCM will turn the MIL ªOFFº on the third
consecutive trip cycle during which the diagnostic has
been run and the fault condition is no longer present.

A history DTC P0601 will clear after 40 consecutive
warm-up cycles have occurred without a fault.

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. Remember to program the replacement
PCM with the correct software and calibration for the
vehicle.

6E±421
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC)
P1167 Fuel System Rich During Decel Fuel Cut Off (Bank1)

StepActionValue(s)Ye sNo
1Was the ªOn-Board (OBD) System Checkº performed?
ÐGo to Step 2
Go to OBD
System
Check
2Are any component related DTCs set?Go to
component
DTC charts
Go to Step 3
31. Place the transmission in Park.
2. Using a Tech 2, HO2S 1 voltage while running warm
engine 75
C ± 95
C (167
F ± 203
F) at 1200
RPM.
3. HO2S 1 voltages should vary within the specified
range. (100 ± 900mV)
4. Quickly open the wide open the throttle for a few
seconds.
Did the voltage suddenly rise toward the low end of the
specified range?
100 ± 600 mV
Go to OBD
System
Check
Go to Step 4
41. Disconnect the fuel pump relay and crank the
engine to relieve the fuel pressure.
2. Install the fuel pressure gauge.
3. Start the engine and idle at normal operating
temperature.
4. Disconnect the vacuum line going to the fuel
pressure regulator.
With the engine running, is the fuel pressure within the
specified range?
280 ± 325Kpa
(41 ± 46psi)
Go to OBD
System
Check
Go to Step 5
51. Ignition ªOFFº.
2. Remove the fuel pump relay and replace it with a
fused jumper which will connect the relay's battery
terminal to the terminal leading to the fuel pump
fuse.
3. While the fuel pump is operating, use pliers to slowly
close the return line (do not exceed the first
specified value).
Using the pliers to restrict the return line, can the
fuel pressure be manipulated to exceed the second
value?
Is the fuel pressure gauge reading near the specified
value?
325KPa
(46psi)
414KPa
(60psi)
Refer to
Diagnostic
Aids
Go to Step 6
6Check the following items;

Faulty fuel pump

Incorrect fuel pump

Incorrect fuel being used

Cold fuel
If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repairÐ

6E±423
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC)
P1169 Fuel System Rich During Decel Fuel Cut Off (Bank2)

StepActionValue(s)Ye sNo
1Was the ªOn-Board (OBD) System Checkº performed?
ÐGo to Step 2
Go to OBD
System
Check
2Are any component related DTCs set?Go to
component
DTC charts
Go to Step 3
31. Place the transmission in Park.
2. Using a Tech 2, HO2S 2 voltage while running warm
engine75 C ± 95 C (167 F ± 203 F) at 1200 RPM.
3. HO2S 1 voltages should vary within the specified
range. (100 ± 900mV)
4. Quickly open the wide open the throttle for a few
seconds.
Did the voltage suddenly rise toward the low end of the
specified range?
100 ± 600 mV
Go to OBD
System
Check
Go to Step 4
41. Disconnect the fuel pump relay and crank the
engine to relieve the fuel pressure.
2. Install the fuel pressure gauge.
3. Start the engine and idle at normal operating
temperature.
4. Disconnect the vacuum line going to the fuel
pressure regulator.
With the engine running, is the fuel pressure within the
specified range?
280 ± 325Kpa
(41 ± 46psi)
Go to OBD
System
Check
Go to Step 5
51. Ignition ªOFFº.
2. Remove the fuel pump relay and replace it with a
fused jumper which will connect the relay's battery
terminal to the terminal leading to the fuel pump
fuse.
3. While the fuel pump is operating, use pliers to slowly
close the return line (do not exceed the first
specified value).
Using the pliers to restrict the return line, can the fuel
pressure be manipulated to exceed the second value?
Is the fuel pressure gauge reading near the specified
value?
325KPa
(46psi)
414KPa
(60psi)
Refer to
Diagnostic
Aids
Go to Step 6
6Check the following items;

Faulty fuel pump

Incorrect fuel pump

Incorrect fuel being used

Cold fuel.
If a problem is found, repair one as necessary.
Was a problem found?
ÐVerify repairÐ

6E±426
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
DTC P1171 ± Fuel System Lean During Acceleration

StepActionValue(s)Ye sNo
1Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
2Are any component-related DTCs set?
Ð
Go to
component
DTC charts
Go to Step 3
31. Check the vehicle's fuel tank for an adequate
amount of fuel.
2. Add fuel to the vehicle's fuel tank if the tank is almost
empty.
Was fuel added to the vehicle's fuel tank?
ÐGo to Step 4Go to Step 5
41. Place the transmission in park.
2. Using a Tech 2, observe HO2S 1 voltage while
running warm engine 75
C-95
C (167
F-203
F) at
1200 RPM.
3. HO2S 1 voltage should vary within the specified
range.
4. Quickly open the throttle too halfway for a few
seconds.
Did the voltage suddenly rise toward the high end of the
specified range?
100-900 mV
Go to Fuel
System
Electrical Test
Go to Step 5
51. Disconnect the fuel pump relay and crank the
engine to relieve the fuel pressure.
2. Install the fuel pressure gauge.
3. Start the engine and idle at normal operating
temperature.
4. Disconnect the vacuum line going to the fuel
pressure regulator.
With the engine running, is the fuel pressure within the
specified range?
280-325 kPa
(41-46 psi)
Go to OBD
System
Check
Go to Step 6
6Check for restricted fuel lines or restricted in-line filter.
Was a problem found?
ÐVerify repairGo to Step 7
71. Ignition ªOFFº.
2. Remove the fuel pump relay and replace it with a
fused jumper which will connect the relay's battery
terminal to the terminal leading to the fuel pump
fuse.
3. While the fuel pump is operating, use pliers to slowly
close the return line (do not exceed the first
specified value).
Using the pliers to restrict the return line, can the fuel
pressure be manipulated to exceed the second
specified value?
325 kPa
(46 psi)
414 kPa
(60 psi)
Go to
Diagnostic
Aids
Go to Step 8
8Check for:

Faulty fuel pump

Restricted fuel pump strainer (sock)

Incorrect fuel pump

Incorrect fuel being used

Hot fuel
Is the action complete?
ÐVerify repairÐ

6E±427
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC)
P1220 Throttle Position Senser2 (TPS2) Circuit Fault
D06RY00111
Circuit Description

The throttle position (TP2) sensor circuit provides a
voltage signal relative to throttle blade angle.
The TPS2 voltage will vary from about 8% (0.4V) to
about 92% (4.6V) at Wide Open Throttle (WOT) in
the specified voltage (about 5V).
This code detects a continuous short to ground or
high in either the circuit or the sensor.
Conditions for setting the DTC

The Ignition is ªONº.

The TPS2 output is more than 93.6 milliseconds, less
than 2.5% or more than 97.5% in the specified voltage
(5V).
Action Taken When the DTC Sets

The PCM will ON the MIL after second trip with
detected fault.

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

The PCM will turn the MIL ªOFFº on the third
consecutive trip cycle during which the diagnostic has
been run and the fault condition is no longer present.
A history DTC P1120 will clear after 40 consecutive trip
cycles during which the warm up cycles have occurred
without a fault.

DTC P1120 can be cleared using the Tech2 ªClear Infoº
function or by disconnecting the PCM battery feed.
Diagnostic Aids
An intermittent may be caused by the following:

Poor connections.

Misrouted harness.

Rubbed through wire insulation.

Broken wire inside the insulation.
Check for the following conditions:

The MAP sensor shares a 5 Volt reference with the
Fuel Tank Pressure. If these codes are also set, it could
indicate a problem with the 5 Volt reference circuit.

The MAP sensor shares a ground with the Fuel Tank
Pressure, the ECT sensor, and the Transmission Fluid

Poor connection at PCM-Inspect harness connectors
for backed out terminals,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, observe the
TP sensor display on the Tech 2 while moving
connectors and wiring harnesses related to the sensor.
A change in the display will indicate the location of
the fault. If DTC P1120 cannot be duplicated, the