Opel Frontera UE. Manual - part 824

6E1–179

X22SE 2.2L ENGINE DRIVEABILITY AND EMISSION

DIAGNOSTIC TROUBLE CODE (DTC) P0405 EXHAUST GAS RECIRCULATION

(EGR) SENSOR CIRCUIT LOW

D06RX113

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 ECM controlled pintle. The ECM controls
the pintle position using inputs from the Throttle Position
(TP) and Manifold Absolute Pressure (MAP) sensors.
The ECM then commands the EGR valve to operate
when necessary by controlling an ignition signal through
the ECM. This can be monitored on a Tech 2 as the
Desired EGR Position.
The ECM 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 ECM. 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 ECM 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 ECM 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 ECM 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.

6E1–180

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

6. Although the ECM 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.

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

6E1–181

X22SE 2.2L ENGINE DRIVEABILITY AND EMISSION

DTC P0405 – EGR Sensor Circuit Low

(Cont'd)

Step

Yes

Value(s)

Action

Check the 5 V reference and signal circuit’s for a poor
connection or proper terminal tension and repair as
necessary.

Was a repair necessary?

—

Go to Step

1. Connect the test light to B+.
2. Probe the signal circuit to the EGR valve.

Does the light illuminate?

—

Go to Step

Check for a short to ground in the EGR valve 5 V
reference circuit and repair as necessary.

Was a repair necessary?

—

Go to Step

Check for an open in the EGR valve 5 V reference
circuit and repair as necessary.

Was a repair necessary?

—

Go to Step

Replace the EGR valve.

Is the action complete?

—

Go to Step

—

Check for a short to ground in the EGR valve signal
circuit and repair as necessary.

Was a repair necessary?

—

Go to Step

Check for an open in the EGR valve signal circuit and
repair as necessary.

Was a repair necessary?

—

Go to Step

Replace the ECM.

Is the action complete?

—

Go to Step

—

Check the affected circuit for a poor connection or
proper terminal at the ECM and repair as necessary.

Was a repair necessary?

—

Go to Step

1. Using the Tech 2, clear the 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

6E1–182

X22SE 2.2L ENGINE DRIVEABILITY AND EMISSION

DIAGNOSTIC TROUBLE CODE (DTC) P0406 EXHAUST GAS RECIRCULATION

(EGR) SENSOR CIRCUIT HIGH

D06RX113

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 ECM controlled pintle. The ECM controls the
pintle position using inputs from the Throttle Position (TP)
and Manifold Absolute Pressure (MAP) sensors. The
ECM then commands the EGR valve to operate when
necessary by controlling an ignition signal through the
ECM. This can be monitored on a Tech 2 as the Desired
EGR Position.
The ECM 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 ECM. 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 ECM detects a continuous short to ground in the
signal circuit or the sensor, then DTC P0406 will set.
Diagnostic Trouble Code P0406 is a type A code.

Conditions for Setting the DTC

IAT is greater than 5

C (41

F).

The ECM 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 ECM 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 Code(s) can be cleared by using
the Tech 2.

Diagnostic Aids

Due to the moisture associated with exhaust systems, the
EGR valve may freeze and stick in colder weather at

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