F0:DATA LIST
| 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