Vauxhall Workshop Service and Repair Manuals

No.

TECH 1 Display

Conditions for Checking

Nominal Value

Trouble Codes

Terminal

33

IAC INTEGRATOR

Engine running at idle speed, operating temperature

Switch off all consumers

56, 57

-

C 20 XE engine:

C 25 XE engine:

120 to 148 steps

120 to 148 steps

Note:

The IAC INTEGRATOR indicates the opening tendency (observance of the pulse duty ratio necessary for nominal engine speed) of the idle speed adjuster.

This means:

Values greater than 128 steps mean larger, values less than 128 steps mean smaller opening cross-sections of the idle speed adjuster.

The IAC INTEGRATOR requires the following information for regulation:

-    ENGINE SPEED (inductive pulse pick-up)

-    Throttle valve closed (via TPS SIGNAL)

-    COOLANT TEMP.

Important:

If there is a malfunction in the idle speed adjuster wiring harness plug, mech. emergency operation is activated.

This increases the idle speed to 800 to 1200 rpm.

Notes on Trouble-shooting:

Nominal Value:

Cause of Fault:

·   See Table F5: ACTUATOR TEST, test step 06

·   See Table F8: ECU CONTROL, test step 01

·   Compare nominal values from

IAC INTEGRATOR

IAC ADAPT. SLOPE

IAC BLOCK LEARN

with each other

IAC INTEGRATOR

120 to 148 steps

IAC ADAPT. SLOPE 

120 to 170 steps

IAC BLOCK LEARN

122 to 135 steps

·   Lack of air

-    Idle speed adjuster jams

-    Bypass air hose blocked or kinked

-    Air cleaner dirty

-    Intake system blocked

·   Excessive air

-    Idle speed adjuster jams

-    Throttle valve open (accelerator cable or throttle valve jams)

-    Intake system leaky

·   Idle speed adjuster defective

·   Coolant temperature sensor P 12 defective

·   Throttle valve potentiometer P 34 defective

·   Inductive pulse pick-up P 35 defective

·   Mass air flow meter P 44 defective

·   Mixture too rich (see Table F0: DATA LIST, test step 38)

·   Control unit K 61 defective