2002 ISUZU AXIOM ECU

6E±480
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P1514 TPS - MAF Correlation Error
060R200061
Circuit Description

The throttle position (TP) sensor circuit provides a
voltage signal relative to throttle blade angle.
The throttle blade angle will vary from about 8 % at
closed throttle to about 92 % at wide open throttle
(WOT).

The mass air flow (MAF) sensor measures the amount
of air which passes through it into the engine during a
given time. The powertrain Control Module (PCM)
uses the mass air flow information to monitor engine
operating conditions for fuel delivery calculations.
A large quantity of air entering the engine indicates
an accelerator or high load situation, while a small
quantity or air indicates deceleration or idle.
The MAF sensor produces a frequency signal which
can be monitored using a Tech 2. The frequency will
vary within a range of around 4 to 7g/s at idle to
around 25 to 40g/s at maximum engine load.
Conditions for setting the DTC

The engine is running.

No MAF sensor DTCs are set.

Throttle actuation mode is not off.

MAF reading-ETC estimated air flow is less than 40g/s
for 250 failures within test 1000 test samples (15.6 m
sec).
Action Taken When the DTC Sets

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

The PCM calculates an air flow value based on idle air
control valve position, throttle position, RPM and
barometric pressure.

The PCM will store condition 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 conditions is no longer present.

A history DTC P1514 will clear after 40 consecutive trip
cycles during which the warm up cycles have occurred
without a fault.

DTC P1514 can be cleared using the Tech 2 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:

Poor connection at PCM - Inspect harness connectors
for backed out terminals, improper mating, broken

6E±484
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC)
P1515 Command - Actual TPS Correlation Error
D06RY00111
Circuit Description

The throttle position (TP) sensor circuit provides a
voltage signal relative to throttle position (blade angle).
The throttle blade angle will vary from about 8 % at
closed throttle to about 92 % at wide open
throttle(WOT).

The DC motor circuit provides a voltage signal relative
to command throttle position (blade angle).

This DTC detects the difference between actual
throttle position and command throttle position.
Conditions for setting the DTC

The ignition is ªONº.

Throttle actuation mode is normal.

Command Throttle position - Actual Throttle position is
more than + 5 % for 100 counts within 1000 test
samples (15.6 m sec) else Actual Throttle position is
less than + 40 % and Command Throttle position -
Actual Throttle position is more than - 5 % or Command
Throttle position - Actual Throttle position is more than
- 20 % for 150 failures within test 1000 test samples
(15.6 m sec).
Action Taken When the DTC Sets

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

The PCM calculates an air flow value based on throttle
blade position, RPM and barometric pressure.
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 P1515 will clear after 40 consecutive trip
cycles during which the warm up cycles have occurred
without a fault.

DTC P1515 can be cleared using the Tech 2 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:

Poor connection at PCM-Inspect harness connectors
for backed out terminals, proper mating, 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 1, TP sensor 2 display on the Tech2 while

6E±487
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC)
P1516 Command - Actual TPS Correlation Error
D06RY00111
Circuit Description

The throttle position (TP) sensor circuit provides a
voltage signal relative to throttle position (blade angle).
The throttle blade angle will vary from about 8% at
closed throttle to about 92 % at wide open throttle
(WOT).

The DC motor circuit provides a voltage signal relative
to command throttle position (blade angle).

This DTC detects the difference between actual
throttle position and command throttle position in
steady state.
Conditions for setting the DTC

The ignition is ªONº.

Throttle Actuation mode is normal.

Command Throttle position-Actual Throttle position is
less than 8 % when desired TPS is steady within 0.5
% for 30 seconds within test samples (30 second)
Action Taken When the DTC Sets

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

The PCM calculates an air flow value based on idle air
control valve position, throttle position, RPM and
barometric pressure.

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 P1516 will clear after 40 consecutive trip
cycles during which the warm up cycles have occurred
without a fault.

DTC P1516 can be cleared using the Tech 2 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:

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 1, TP sensor 2 display on the Tech2 while
moving connectors and wiring harnesses related to the
sensor.
A change in the display will indicate the location of
the fault. If DTC P1516 cannot be duplicated, the

6E±490
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC)
P1523 Actuator Control Return Performance
D06RY00111
Circuit Description

The throttle position (TP) sensor circuit provides a
voltage signal relative to throttle position (blade angle).
The throttle blade angle will vary from about 8 % at
closed throttle to about 92 % at wide open
throttle(WOT).

The DC motor circuit provides a voltage signal relative
to command throttle position (blade angle).

This DTC detects if the throttle return to the default
position at key on is steady.
Conditions for setting the DTC

The ignition is ªONº.

Normalized TPS is less than 7 % or Normalized TPS
is more than 25 %.
Action Taken When the DTC Sets

The PCM will not turn the malfunction indicator lamp
(MIL) ªONº.

The PCM will store conditions which were present
when the DTC was set as Failure Records only. This
information will not be stored as Freeze Frame 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 P1523 will clear after 40 consecutive trip
cycles during which the warm up cycles have occurred
without a fault.

DTC P1523 can be cleared using the Tech 2 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:

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 1, TP sensor 2 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 P1523 cannot be duplicated, the
information included in the Failure Records data can
be useful in determining vehicle mileage since the
DTC was last set.

6E±495
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P1625 PCM Unexpected Reset
Circuit Description
The powertrain control module (PCM) monitors
unexpected PCM reset. This will not turn on MIL light on,
only record code DTC P1625.
Conditions for Setting the DTC

Clock or COP (Computer Operating Properly) reset.
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 as Failure Records only. This
information will not be stored as Freeze Frame 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 P1625 will clear after 40 consecutive
warm-up cycles have occurred without a fault.

DTC P1625 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:

P1625 stored alone does not need diagnosis. Clear
DTC code.
DTC P1625 ± PCM Unexpected Reset

StepActionValue(s)Ye sNo
1Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
21. Ignition is ªONº.
2. Install the Tech 2.
3. Start the engine and let it Idle.
4. On the Tech 2, select ªDTC infoº.
Does the Tech 2 indicate DTC P1625 failed?
ÐGo to Step 3
Go to
Diagnostic
Aids
31. Ignition is ªONº.
2. Clear DTC P1625 by using the Tech 2 ªClear Infoº.
3. Start the engine and let it Idle.
4. On the Tech 2, select ªDTC infoº.
Does the Tech 2 indicate DTC P1625 failed?
ÐGo to Step 4
Go to
Diagnostic
Aids
41. Check for aftermarket electronics, such as
transceiver, stereos, and anti theft devices. They
may radiate EMI into the control system if they are
improperly installed. (This may cause a false sensor
reading and turn on the MIL.)
2. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repairÐ

6E±496
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC)
P1635 Reference Voltage # 1 Circuit Fault
D06RY00093
Circuit Description
The TP sensor # 1 shares a 5 Volt reference with the
PCM.
If the PCM detects the 5 Volt reference for the TP sensor #
1 is failure, DTCP1635 will be set.
Conditions for setting the DTC

The ignition is ªONº.

The 5 Volt reference voltage for the TP sensor # 1 is
less than 4 volts.

The 5 Volt reference voltage for the TP sensor # 1 is
more than 5 volts.
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 as Failure Records only. This
information will not be stored as Freeze Frame 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 P1635will clear after 40 consecutive trip
cycles during which the warm up cycles have occurred
without a fault.

DTC P1635 can be cleared using the Tech 2 ªClear
Infoº function or by disconnecting the PCM battery
feed. Tech2 ª Clear Infoº function or by disconnecting
the PCM battery feed.

6E±498
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC)
P1639 Reference Voltage # 2 Circuit Fault
060R200064
Circuit Description
The AP sensor # 1shares a 5 Volt reference with the PCM.
If the PCM detects the 5 Volt reference for the AP sensor
# 1 is failure, DTC P1635 will be set.
Conditions for setting the DTC

The ignition is ªONº.

The 5 Volt reference voltage for the AP sensor # 1 is
less than 4 volts.

The 5 Volt reference voltage for the AP sensor # 1 is
more than 5 volts.
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 as Failure Records only. This
information will not be stored as Freeze Frame 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 P1639 will clear after 40 consecutive trip
cycles during which the warm up cycles have occurred
without a fault.

DTC P1639 can be cleared using the Tech 2 ªClear
Infoº function or by disconnecting the PCM battery
feed. Tech 2 ªClear Infoº function or by disconnecting
the PCM battery feed.

6E±500
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC)
P1640 Driver-1-Output Circuit Fault (ODM)
Circuit Description
Output driver modules (ODMs) are used by the
powertrain control module (PCM) to turn ªONº many of
the current-driven devices that are needed to control
various engine and transmission functions. Each ODM is
capable of controlling up to 7 separate outputs by
applying ground to the device which the PCM is
commanding ªONº.
Unlike the Quad Driver Modules (QDMs) used in prior
model years, ODMs have the capability of diagnosing
each output circuit individually. DTC P1640 set indicates
an improper voltage level has been detected on an ODM
output.
Since A/C is an option, No A/C will cause the air
conditioning clutch relay output to always fail. If a fault is
seen on the air conditioning clutch relay output, it will not
be logged as a fault until the A/C request input interrupts a
high voltage, indicating that A/C has been installed.
Conditions for Setting the DTC

Ignition ªONº.

Engine running.

Ignition voltage is above 13.2 volts for 4 seconds.

Output voltage does not equal ignition voltage when
output is ªOFFº or output voltage is not less than 1 volt
when output is ªONº.

Above conditions occur for at least 1 second.
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 as Failure Records only. This
information will not be stored as Freeze Frame data.
Conditions for Clearing the MIL/DTC

A history DTC P1640 will clear after 40 consecutive
warm-up cycles occur without a fault.

DTC P1640 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:

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, disconnect
the PCM, turn the ignition ªONº and observe a
voltmeter connected to the suspect driver circuit at the
PCM harness connector while moving connectors and
wiring harnesses related to the MIL. A change in
voltage will indicate the location of the fault.

Poor connection at component ± Examine for
damaged connectors, unplugged connector, or
damaged terminals at the following locations:
Instrument cluster harness, canister purge solenoid,
A/C clutch relay. An open ignition feed circuit at any of
these components will cause DTC P1640 to be set.
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.
4. The Tech 2 Driver Module Status indicates the PCM
pin that is affected.
9. The Tech 2 may indicate ªshort circuitº even when
the problem is an open circuit. The cause of an
open circuit may be in the component itself-lamp,
purge, solenoid, or A/C compressor relay.
11.A short to ground on the ignition side of the
component will blow the fuse. Since the fuse was
checked in Step 2, a short to ground would be
between the affected component and the PCM.