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Isuzu Rodeo UE. Manual - part 217

6E1–239

RODEO X22SE 2.2L ENGINE DRIVEABILITY AND EMISSION

DTC P0404 EGR Circuit Range/Performance

Step

Action

Value(s)

Yes

Was the ”On–Board Diagnostic (OBD) System Check”
performed?

—

Go to Step 2

Go to

Powertrain

OBD System

Check

1. Turn the ignition switch ON, with the engine OFF.
2. Install a Tech 2.
3. Command the EGR valve to the specified values.

Does the Actual EGR Position follow the Desired EGR
Position?

25%, 50%,

75%, 100%

Go to Step

Go to Step 3

1. Turn the ignition switch ON, with the engine OFF.
2. Disconnect the EGR valve electrical connector.
3. With a test light connected to B+, probe the ground

circuit to the EGR valve.

Does the light illuminate?

—

Go to Step 4

Go to Step 5

1. Connect the test light to ground.
2. Probe the EGR control circuit to the EGR valve.
3. Command the EGR valve to the specified values

using a Tech 2.

As the command is raised, does the test light glow
brighter, flash or maintain a steady glow?

25%, 50%,

75%, 100%

Go to Step 6

Go to Step 7

Repair the open or poor connection in the EGR ground
circuit.

Is the action complete?

—

Go to Step

—

With the test light still connected to ground, probe the
signal circuit.

Is the action complete?

—

Go to Step 8

Go to Step 9

With the test light still connected to ground, again probe
the control circuit without commanding the EGR valve
with the Tech 2.

Does the test light illuminate?

—

Go to Step

Check the signal circuit for a short to voltage and repair
as necessary.

Was a repair necessary?

—

Go to Step

With a Digital Voltmeter (DVM) connected to ground,
probe the 5 V reference circuit.

Is the voltage measured near the specified value?

5 V

Go to Step

Check the control circuit for a short to voltage and
repair as necessary.

Was a repair necessary?

—

Go to Step

Connect the test light to B+ and again probe the control
circuit.

Does the light illuminate?

—

Go to Step

6E1–240

RODEO X22SE 2.2L ENGINE DRIVEABILITY AND EMISSION

DTC P0404 EGR Circuit Range/Performance

(Cont'd)

Step

Yes

Value(s)

Action

Replace 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?

—

Go to Step

—

Check the EGR ground circuit for a poor connection or
proper terminal tension at the PCM and repair as
necessary.

Was a repair necessary?

—

Go to Step

Check the 5 V reference circuit for a short to voltage
and repair as necessary.

Was a repair necessary?

—

Go to Step

Check the control circuit for a short to ground and repair
as necessary?

Was a repair necessary?

—

Go to Step

Check the control circuit for an open or poor connection
at the EGR valve electrical connector and repair as
necessary.

Was a repair necessary?

—

Go to Step

Replace the EGR valve.

Is the action complete?

—

Go to Step

—

Check the PCM electrical connector for a poor
connection and repair as necessary.

Was a repair necessary?

—

Go to Step

1. Using the Tech 2, clear Diagnostic Trouble Codes.
2. Start engine and idle at normal operating

temperature.

3. Operate vehicle within the conditions for setting this

Diagnostic Trouble Code as specified in the
supporting text.

Does the Tech 2 indicate that this diagnostic ”Ran and
Passed?”

—

Verify repair

Go to Step 2

6E1–241

RODEO X22SE 2.2L ENGINE DRIVEABILITY AND EMISSION

DIAGNOSTIC TROUBLE CODE (DTC) P0405 EXHAUST GAS RECIRCULATION

(EGR) SENSOR CIRCUIT LOW

D06RX055

Circuit Description

An Exhaust Gas Recirculation (EGR) system is used to
lower Oxides of Nitrogen (NOx) emission levels caused
by high combustion temperatures. It accomplishes this
by feeding small amounts of exhaust gases back into the
combustion chamber. When the air/fuel mixture is diluted
with the exhaust gases, combustion temperatures are
reduced.
A linear EGR valve is used on this system. The linear
EGR valve is designed to accurately supply exhaust
gases to the engine without the use of intake manifold
vacuum. The valve controls exhaust flow going into the
intake manifold form the exhaust manifold through an
orifice with a PCM controlled pintle. The PCM controls
the pintle position using inputs from the Throttle Position
(TP) and Manifold Absolute Pressure (MAP) sensors.
The PCM then commands the EGR valve to operate
when necessary by controlling an ignition signal through
the PCM. This can be monitored on a Tech 2 as the
Desired EGR Position.
The PCM monitors the results of its command through a
feedback signal. By sending a 5 volt reference and a
ground to the EGR valve, a voltage signal representing
the EGR valve pintle position is sent to the PCM. This
feedback signal can also be monitored on a Tech 2 and is
the actual position of the EGR pintle. The Actual EGR
Position should always be near the commanded or
Desired EGR Position.

If the PCM detects a continuous short to ground in the
signal circuit or the sensor, then Diagnostic Trouble Code
P0405 will set. DTC P0405 is a type A code.

Conditions for Setting the DTC

IAT is greater than 5

C (41

F).

The PCM sees less than 0.10 voltage from the EGR
valve sensor.

A malfunction is present for 10 seconds.

Action Taken When the DTC Sets

The Malfunction Indicator Lamp (MIL) will illuminate
the first time the malfunction is detected.

The PCM will record operating conditions at the time
the diagnostic fails.

A history Diagnostic Trouble Code is stored.

The EGR Valve is disabled.

Conditions for Clearing the MIL/DTC

The MIL will turn OFF after three consecutive ignition
cycles in which the diagnostic runs without a fault.

A history Diagnostic Trouble Code will clear after 40
consecutive warm up cycles without a fault.

Diagnostic Trouble Codes can be cleared by using the
Tech 2.

6E1–242

RODEO X22SE 2.2L ENGINE DRIVEABILITY AND EMISSION

Diagnostic Aids

Due to the moisture associated with exhaust systems, the
EGR valve may freeze and stick in colder weather at
times. After the vehicle is brought into a warm shop for
repairs, the valve warms and the problem disappears. By
watching the Actual EGR and Desired EGR Positions on
a cold vehicle with a Tech 2, the fault can be verified
easily. Check the freeze frame data to determine if the
Diagnostic Trouble Code set when the vehicle was cold
by viewing the Engine Coolant Temperature (EGR).

Test Description

Number(s) below refer to the step number(s) on the
Diagnostic Chart:
1. The Powertrain OBD System Check prompts the

technician to complete some basic checks and store
the freeze frame and failure records data on the
Tech 2 if applicable. This creates an electronic copy
of the data taken when the fault occurred. The
information is then stored on the Tech 2 for later
reference.

2. Commanding the EGR valve open determines

whether the EGR system can control the EGR valve
accurately and if the fault is present.

3. If the EGR valve 5 volt reference is shorted to

ground, the DVM will read no voltage and an
additional Diagnostic Trouble Code will be set and
engine performance will be poor. When this circuit
is open, only a Diagnostic Trouble Code P0405 will
be set.

4. Jumping the 5 volt reference circuit to the signal

circuit checks the signal circuit and PCM. The Tech
2 should display the Actual EGR Position as 100% if
the signal circuit and PCM are OK.

6. Although the PCM and circuitry acted correctly in the

previous step, a problem may still lie within the
terminals which would not show up in probe type
testing. Check the terminals for being backed out,
improperly formed or damaged, and for poor
tension.

10. All circuits to the EGR valve are OK at this point.

The fault lies internally in the EGR valve and
therefore must be replaced. Be sure all gasket
material is removed from the EGR mounting
surface. Even a small amount of material may
cause a Diagnostic Trouble Code P0405 to set.
Refer the EGR Valve for on vehicle service of the
EGR valve.

13. The replacement PCM must be reprogrammed and

the crankshaft position system variation procedure
must be performed. Refer to the latest procedures
for PCM reprogramming and Powertrain Control
Module for the Tooth Error Correction Variation
Procedure.

14. Check the terminals for being backed out,

improperly formed or damaged, and for poor
tension.

DTC P0405 – EGR Sensor Circuit Low

Step

Action

Value(s)

Yes

Was the Powertrain On–Board Diagnostic (OBD)
System Check performed?

—

Go to Step 2

Go to

Powertrain

OBD System

Check

1. Turn the ignition switch ON, with the engine OFF.
2. Install a Tech 2.
3. Command the EGR valve to the specified values.

Does the Actual EGR Position follow the Desired EGR
Position?

25%, 50%,

75%, 100%

Go to Step

Go to Step 3

1. Turn the ignition switch ON, with the engine OFF.
2. Disconnect the EGR valve electrical connector.
3. With a Digital Voltmeter (DVM) connected to

ground, probe the 5 V reference circuit to the EGR
valve.

Does the DVM read near the specified value?

5 V

Go to Step 4

Go to Step 5

Jumper the EGR valve 5 volt reference circuit to the
signal circuit.

Does the Actual EGR Position display the specified
value?

100%

Go to Step 6

Go to Step 7

1. Connect the test light to B+.
2. Probe the 5 V reference circuit to the EGR valve.

Does the test light illuminate?

—

Go to Step 8

Go to Step 9

Content .. 215 216 217 218 ..