P1211

DIAGNOSTIC TROUBLE CODES P1211, P1212
Idle Air Control (IAC) valve, output from control module low/high
No continuity or shorting to ground/batt+

Fault Symptom.
Idle uneven, slow or fast

Condition
No continuity or shorting to ground/batt+ in the circuit to pin 4

Diagnostic Procedure.
1. Activate the ISAT commands "CALC. AIR MASS" and "ACTUAL AIR MASS" in the "READ FUNCTIONS" menu or activate the ISAT command "IAC VALVE" in the "ACTIVATE" menu and listen to check whether the valve is working (0.5 Hz).

If it is, proceed to step 3.

2. With the ignition switch in the DRIVE position, unplug the IAC valve connector and check whether current is present on pin 2 of the IAC valve.

If it is not, check the lead between pin 2 of the valve and fuse 17 for continuity/shorting.

3. Measure the resistance across pins 1 and 2 of the valve.
The resistance should be 6-10 ohms.

If it is not, change the IAC valve.





4. With the ignition switched OFF and all current consuming equipment disconnected, measure the resistance across pin 1 of the valve connector and a good grounding point on the engine. The resistance should be 10-500 kOhms.

If the resistance is OK, check the valve manually for binding.
If the valve is OK, proceed to step 6.
If the resistance is NOT OK, proceed to step 5.

5. Check the lead between pin 1 of the IAC valve and pin 4 of the MOTRONIC control module for continuity/shorting.

6. Clear all the trouble codes and drive the car on the road to check whether any codes are generated afresh.

If they are, continue at "Before Replacing Control Module" for further diagnostic instructions. Before Replacing A Control Module