F0: Data List - Test Step 18 Iac Integrator Opel Frontera A

Note:

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

This means:

128 steps is the middle of the regulating range,

values > 128 steps mean larger,

values < 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.

Trouble-shooting: Nominal Value: Cause of Fault:

(If nominal value is not attained)

· First check TPS SIGNAL and

ENGINE SPEED.

If OK,start trouble-shooting.

· If IAC PULSE RATIO constantly IAC PULSE RATIO 32 to 60 % · Lack of air

between 80 and 100 % IAC INTEGRATOR 96 to 160 steps - Idle speed adjuster sticks, does not open

and Carry out F5:ACTUATOR TEST, test step 01

IAC INTEGRATOR constantly - Bypass air hose blocked or kinked.

at a value > 128 steps

· If IAC PULSE RATIO constantly IAC PULSE RATIO 32 to 60 % · Throttle valve open,

between 0 and 32 % IAC INTEGRATOR 96 to 160 steps accelerator cable or throttle valve jams

and

IAC INTEGRATOR constantly · Idle speed adjuster jams, does not close

at a value < 128 steps Carry out F5:ACTUATOR TEST, test step 01

Other causes of faults: · Control unit defective

(test see table 5 F5:ACTUATOR TEST,

test step 01)

· Air flow meter defective

(test see test step 07)

· TPS SIGNAL incorrect

(see test step 09)

· Mixture too rich

(see test step 30)