2002 ISUZU AXIOM sensor

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±300
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS

The PCM will store conditions which were present
when the DTC was set as Freeze Frame and in the
Failure Records data.
Diagnostic Aids
Check for the following conditions:

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

Ensure EGR valve is correctly mounted. See
On-Vehicle Service.
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.
NOTE: If the EGR valve shows signs of excessive heat,
check the exhaust system for blockage (possibly a
plugged catalytic converter) using the ªRestricted
Exhaust System Checkº.
Test Description
Number(s) below refer to the step number(s) on the
Diagnostic Chart
3. A malfunctioning MAP sensor can set an EGR DTC.
The MAP sensor could send a constant signal which
is not low enough to set a low MAP DTC. The
constant signal from the MAP sensor also may not
be high enough to set a high MAP DTC. This step
verifies that the MAP sensor is responding.

6E±301
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
DTC P0401 ± EGR Flow Insufficient

StepActionValue(s)Ye sNo
1Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
2Is DTC P1404 also set?
Ð
Go to DTC
1404
Go to Step 3
31. Start the engine.
2. Monitor the MAP signal with a Tech 2 while idling.
3. While idling, jab the accelerator pedal about halfway
down and immediately let the engine return to idle.
Did the MAP value on the Tech 2 show an immediate
large change?
ÐGo to Step 5Go to Step 4
4Replace the MAP sensor.
Is the action complete?
ÐVerify repairÐ
51. Inspect the exhaust system for modification of
original installed parts or leaks.
2. If a problem was found, repair exhaust system as
necessary.
Was a condition present that required repair?
ÐGo to Step 8Go to Step 6
61. Remove the EGR valve.
2. Visually and physically inspect the pintle, valve
passages and the adapter for excessive deposits or
any kind of a restriction.
3. If a problem is found, clean or replace EGR system
components as necessary.
Was a condition present that required repair?
ÐGo to Step 8Go to Step 7
71. Remove the EGR inlet and outlet pipes from the
exhaust manifold and the intake manifold.
2. Inspect the manifold EGR ports and the EGR inlet
and outlet pipes for a blockage caused by excessive
deposits or other damage.
3. If a problem is found, correct the condition as
necessary.
Was a condition present that required repair?
ÐGo to Step 8
Refer to
Diagnostic
Aids
81. Review and record the Tech 2 Failure Records data.
2. Clear DTC and monitor the Tech 2 System Info
Screen while operating the vehicle as specified in
ªDiagnostic Aidsº.
3. Using a Tech 2, monitor ªDTCº info for DTC P0401
until the DTC P0401 test runs.
4. Note the test result.
Does the Tech 2 indicate DTC P0401 failed this
ignition?
ÐÐ
Repair
complete

6E±305
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
DTC P0404 ± EGR Open 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 ªONº, 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 ªDTCº info for DTC P0404
until the DTC P0404 test runs. Note the result.
Does the Tech 2 indicates DTC P0404 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.
ÐVerify repair
Is the action
complete?
51. Remove EGR valve from Engine.
2. Inspect EGR valve whether there is any excessive
carbon deposit on EGR shaft.
Was excessive carbon deposit on EGR valve shaft?
ÐGo to Step 6Go to Step 7
61. Clean up EGR valve shaft and inside of EGR valve.
2. Visually inspect damage of pintle and seat if is bent,
leakage may occur.
Was there any severe damage which affects function?
ÐGo 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 EGR Control Test.
6. Use the ªUPº arrow to increase the EGR from 0% to
40%.
Did EGR work properly?
ÐÐGo to Step 8
8Replace the EGR valve.
Does DTC P0404 still fail ªDTCº test on the Tech 2?
ÐGo to Step 9Verify repair
9Replace 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±307
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
DTC P0405 ± EGR Low Voltage

StepActionValue(s)Ye sNo
1Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
21. Ignition ªONº, 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 ªDTCº info for DTC P0405
until the DTC P0405 test runs. Note the result.
Does the Tech 2 indicates DTC P0405 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. Disconnect the EGR harness connector.
2. Ignition ªONº.
3. At the EGR valve, use a DVM to check the voltage
at the 5 volt reference wire (BLU/RED) and ground.
Did the DVM indicate the specified value?
4±6 VGo to Step 6Go to Step 7
61. Disconnect the EGR harness connector.
2. Measure resistance between terminal 5 volt
reference wire and ground.
Was resistance in range?
5±5.5 K
Go to Step 10Go to Step 17
71. Ignition ªONº.
2. At the PCM connector, backprobe with a DVM at the
5 volt reference for the EGR valve.
Did the DVM indicate the specified value?
4±6 VGo to Step 8Go to Step 18
8Repair the open 5 volt reference circuit.
Is the action complete?
ÐVerify repairÐ
9Repair the damaged sensor ground wire.
Is the action complete?
ÐVerify repairÐ
101. Disconnect the EGR harness
2. Use an ohmmeter to measure between the pintle
position pin and the sensor ground pin on the EGR
valve.
NOTE: J-35616 Connector Test Adapter Kit may be
useful for gaining access to the recessed pins on the
valve.
Was the ohmmeter reading approximately equal to the
specified value?
1 to 1.25 K
Go to Step 13Go to Step 17
111. Ignition ªONº.
2. Backprobe with a DVM to measure voltage at EGR
valve pintle position pin and sensor ground pin.
Was voltage in range?
Less than
0.1 V
Go to Step 17Go to Step 12

6E±308
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
DTC P0405 ± EGR Low Voltage

 
StepNo Ye s Value(s) Action
121. Ignition ªONº.
2. Backprobe with a DVM to measure voltage at PCM
sensor ground pin and pintle position pin.
Was voltage in range?
Less than
0.1 V
Go to Step 13Go to Step 18
131. Ignition ªOFFº.
2. Disconnect the EGR harness.
3. Check short circuit between EGR pintle position
circuit and EGR ground circuit.
Was any short circuit?
ÐGo to Step 14Go to Step 18
14Locate and repair the short to ground in the pintle
position circuit
Is the action complete?
ÐVerify repairÐ
151. Ignition ªOFFº.
2. Disconnect the PCM.
3. Ignition ªONº.
4. Measure the voltage between the EGR pintle
position circuit and ground.
Is the measured voltage near the specified value?
Less than
0.1 V
Go to Step 17Go to Step 16
16Check for a short circuit between other wires and the
pintle position circuit
Is there any short circuit?
Ð
Repair short
circuit and then
Verify repair
Go to Step 17
17Replace the EGR valve.
Does DTC P1404 still fail ªDTC test on the Tech 2?
ÐGo to Step 18Verify repair
18Examine the PCM pin and terminal connection.
Was there a damaged terminal?
ÐGo to Step 4Go to Step 19
19Replace 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±310
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
DTC P0406 ± EGR High Voltage

StepActionValue(s)Ye sNo
1Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
21. Ignition ªONº, 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 ªDTCº info for DTC P0406
until the DTC P0406 test runs. Note the result.
Does the Tech 2 indicates DTC P0406 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 repair
Is the action
complete?
51. Disconnect the EGR harness connector.
2. Ignition ªONº.
3. At the EGR valve, use a DVM to check the voltage
at the 5 volt reference wire (BLU/RED).
Did the DVM indicate the specified value?
4±6 VGo to Step 8Go to Step 6
61. Ignition ªONº.
2. At the PCM connector, backprobe with a DVM at the
5 volt reference for the EGR valve.
Did the DVM indicate the specified value?
4±6 VGo to Step 7Go to Step 16
7Repair the open 5 volt reference circuit
Is the action complete?
ÐVerify repairÐ
81. Ignition ªOFFº
2. Disconnect the EGR harness.
3. Use a DVM to check for an resistance between 5 V
reference and Sensor Ground at EGR sensor
terminals.
NOTE: J-35616 Connector Test Adapter Kit may be
useful for gaining access to the recessed pins on the
valve.
Was the measured resistance in range?
5 to 5 K
Go to Step 9Go to Step 15
91. Ignition ªOFFº.
2. Disconnect the EGR harness.
3. Use a DVM to check for an resistance between
Sensor Ground and Signal Wire at EGR sensor
terminal.
Is there an open circuit?
ÐGo to Step 15Go to Step 10
101. Ignition ªOFFº.
2. Disconnect the EGR harness at PCM connector.
3. Use a DVM to check for shorted wire between S37
and F53.
Is there a shorted wire?
ÐGo to Step 14Go to Step 11

6E±311
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
DTC P0406 ± EGR High Voltage

 
StepNo Ye s Value(s) Action
111. Ignition ªONº.
2. Use a DVM to backprobe at terminal Connector of
EGR valve for voltage.
Was measured voltage more than 4.8 V?
more than
4.8 V
Go to Step 12Go to Step 12
121. Ignition ªONº.
2. Stay the EGR harness connected.
3. Check voltage by backprobing at PCM S37
terminal.
Was voltage more than 4.8 V?
4.8 VGo to Step 16Go to Step 13
131. Locate short circuit at EGR harness between
BLU/RED to GRY/RED or GRY/RED to YEL,
BLU/RED.
2. Replace EGR harness.
Is the action complete?
ÐVerify repairÐ
14Replace EGR harness.
Is the action complete?
ÐVerify repairÐ
15Replace the EGR valve.
Does DTC P1404 still fail ªDTC test on the Tech 2?
ÐGo to Step 16Verify repair
16Replace 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