Opel Frontera UE. Manual - part 828

6E1–195

X22SE 2.2L ENGINE DRIVEABILITY AND EMISSION

DIAGNOSTIC TROUBLE CODE (DTC) P0506 IDLE CONTROL SYSTEM RPM

LOWER THAN EXPECTED

D06RX112

Circuit Description

The engine control module (ECM) controls engine idle
speed by adjusting the position of the idle air control (IAC)
motor pintle. The IAC is a bi–directional stepper motor
driven by two coils. The ECM applies current to the IAC
coils in steps (counts) to extend the IAC pintle into a
passage in the throttle body to decrease air flow. The
ECM reverses the current to retract the pintle, increasing
air flow. This method allows highly accurate control of idle
speed and quick response to changes in engine load. If
the ECM detects a condition where too low of an idle
speed is present and the ECM is unable to adjust idle
speed by increasing the IAC counts, DTC P0506 will set,
indicating a problem with the idle control system.  DTC
P0506 is a type B code.

Conditions for Setting the DTC

D

No intrusive tests being run.

D

Engine run time is more than 125 seconds.

D

No TPS, VSS, ECT, EGR, MAP, IAT, low voltage, fuel
system or canister purge Diagnostic Trouble Codes
are set.

D

Barometric pressure is greater than 72.7 kPa.

D

Canister purge duty cycle is above 0%.

D

Engine coolant temperature (ECT) is above 50

°

C

(122

°

F).

D

Intake air temperature above –40

°

C (–40

°

F).

D

MAP is less than 60 kPa.

D

Ignition voltage is between 9.5 volts and 16 volts.

D

The throttle is closed.

D

All conditions are met for 10 seconds.

D

Engine speed is at least 100 RPM lower than desired
idle, based upon ECM expectations.

Action Taken When the DTC Sets

D

The ECM will illuminate the malfunction indicator lamp
(MIL) after the second consecutive trip in which the
fault is detected.

D

The ECM will store conditions which were present
when the Diagnostic Trouble Code was set as Freeze
Frame and in the Failure Records data.

Conditions for Clearing the MIL/DTC

D

Diagnostic Trouble Code P0506 can be cleared by
using the Scan Tool’s ”Clear Info” function.

Diagnostic Aids

Check for the following conditions:

D

Poor connection at ECM or IAC motor – Inspect
harness connectors for backed–out terminals,
improper mating, broken locks, improperly formed or
damaged terminals, and poor terminal–to–wire
connection.

6E1–196

X22SE 2.2L ENGINE DRIVEABILITY AND EMISSION

D

Damaged harness – Inspect the wiring harness for
damage; shorts to ground, shorts to battery positive,
and open circuits.

D

Restricted air intake system – Check for a possible
collapsed air intake duct, restricted air filter element, or
foreign objects blocking the air intake system.

D

Throttle body – Check for objects blocking the IAC
passage or throttle bore, excessive deposits in the IAC
passage and on the IAC pintle, and excessive deposits
in the throttle bore and on the throttle plate.

D

Large vacuum leak – Check for a condition that causes
a large vacuum leak, such as an incorrectly installed or
faulty PCV valve or brake booster hose disconnected.

Reviewing the Failure Records vehicle mileage since the
diagnostic test last failed may help determine how often
the condition that caused the Diagnostic Trouble Code to
be set occurs. This may assist in diagnosing the
condition.

DTC P0506 – Idle Control System RPM Lower Than Expected

 

Step

Action

Value(s)

Yes

No

1

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

—

Go to Step  2 

Go to OBD

System

Check 

2

Are any other Diagnostic Trouble Codes set?

—

Go to other

Diagnostic

Trouble Code

first

Go to Step  3 

3

1. Start the engine.
2. Turn all accessories OFF (A/C, rear defroster, etc.)
3. Using a Tech 2, command RPM up to 1500, down to

500, and then up to 1500 while monitoring ”Engine
Speed” on the Tech 2.

Does the ”Engine Speed” remain within the specified
value of ”Desired Idle” for each RPM command?

+/–50 RPM

No trouble

found. Go to

Diagnostic

Aids 

Go to Step  4 

4

1. Check the following circuits for an open, short to

voltage, short to ground, or poor connection at the
PCM:

D

IAC ”A” low

D

IAC ”A” high

D

IAC ”B” low

D

IAC ”B” high

2. If a problem is found, repair as necessary.

Was a problem found?

—

Verify repair

Go to Step  5

5

Visually/physically inspect for the following conditions:

D

Throttle body tampering (adjustment screw plug
removed).

D

Restricted air intake system. Check for a possible
collapsed air intake duct, restricted air filter
element, or foreign objects blocking the air intake
system.

D

Throttle body. Check for objects blocking the IAC
passage or throttle bore, excessive deposits in
the IAC passage and on the IAC pintle, and
excessive deposits in the throttle bore and on the
throttle plate.

Do any of the above require a repair?

—

Refer to

appropriate

section for

on–vehicle

service

Go to Step  6

6

1. Check for a poor connection at the IAC harness

connector.

2. If a problem is found, replace faulty terminals as

necessary.

Was a problem found?

—

Verify repair

Go to Step  7

6E1–197

X22SE 2.2L ENGINE DRIVEABILITY AND EMISSION

DTC P0506 – Idle Control System RPM Lower Than Expected

  (Cont'd)

Step

No

Yes

Value(s)

Action

7

Using a Digital Voltmeter (DVM), check the IAC valve
solenoids (A and B) for the following conditions:

D

An open circuit

D

A short to ground (the IAC body)

D

A short together

Was the problem found?

—

Go to Step  8

Go to Step  9

8

Replace the IAC valve.

Is the action complete?

—

Verify repair

—

9

Replace the ECM.

Is the action complete?

—

Verify repair

—

6E1–198

X22SE 2.2L ENGINE DRIVEABILITY AND EMISSION

DIAGNOSTIC TROUBLE CODE (DTC) P0507 IDLE CONTROL SYSTEM RPM

HIGHER THAN EXPECTED 

D06RX112

Circuit Description

The engine control module (ECM) controls engine idle
speed by adjusting the position of the idle air control (IAC)
motor pintle. The IAC is a bi–directional stepper motor
driven by two coils. The ECM applies current to the IAC
coils in steps (counts) to extend the IAC pintle into a
passage in the throttle body to decrease air flow. The
ECM reverses the current to retract the pintle, increasing
air flow. This method allows highly accurate control of idle
speed and quick response to changes in engine load. If
the ECM detects a condition where too high of an idle
speed is present and the ECM is unable to adjust idle
speed by increasing the IAC counts, Diagnostic Trouble
Code P0507 will set, indicating a problem with the idle
control system.   DTC P0507 is a type B code.

Conditions for Setting the DTC

D

No intrusive tests being run.

D

Engine run time is more than 125 seconds.

D

No TPS, VSS, ECT, EGR, MAP, IAT, low voltage, fuel
system or canister purge DTCs are set.

D

Barometric pressure is greater than 72.7 kPa.

D

Canister purge duty cycle is above 0%.

D

Intake air temperature above –40

°

C (–40

°

F).

D

Engine coolant temperature (ECT) is above 50

°

C

(122

°

F).

D

Ignition voltage is between 9.5 volts and 16 volts.

D

The throttle is closed.

D

All conditions are met for 10 seconds.

D

MAP is less than 60 kPa.

D

Engine speed is at least 200 RPM lower than desired
idle, based upon PCM’s expectations.

Action Taken When the DTC Sets

D

The PCM will illuminate the malfunction indicator lamp
(MIL) after the second consecutive trip in which the
fault is detected.

D

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

D

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

D

A history Diagnostic Trouble Code P0507 will clear
after 40 consecutive warm–up cycles have occurred
without a fault.

D

Diagnostic Trouble Code P0507 can be cleared by
using the Scan Tool’s ”Clear Info” function.

Diagnostic Aids

Check for the following conditions:

D

Poor connection at PCM or IAC motor – Inspect
harness connectors for backed–out terminals,
improper mating, broken locks, improperly formed or
damaged terminals, and poor terminal–to–wire
connection.