The A/C pushbutton control module (N22) has DTC memory and data output. The diagnostic trouble codes and data are displayed via the temperature display window. The stored DTC's will remain in memory even with the vehicle battery disconnected. The DTC memory differentiates between current and intermittent faults. All DTC's can also be read with the Hand-Held Tester (HHT).
		P83.40-0313-01

Preparations for DTC Readout 1. Review 11 , 12 , 14 , 15 , 20 , 21 , 23 , 31 31 2. Connect HHT, see section 0, readout DTC's. DTC'S which are transmitted via the instrument cluster (IC) series interface, must be readout and the DTC's noted via the DTC memory in the instrument cluster, finally erase the DTC's. 3. Ignition: ON 4. Temperature selector . 5. Within 20 seconds press and simultaneously for more than 5 seconds. 6. The LED in flashes and the display shows . 7. Press repeatedly until all DTC's are displayed. Record each DTC as it is displayed. The current faults (refer to table) are displayed first, next, the intermittant failures (e.g. 45 °5) are displayed in the display window next to the symbol. ° will apppear after the last DTC is displayed. Press again, (delete, erase) will then appear in display. 8. To erase: Press and simultaneously for more than 5 seconds and the display shows "-- -". To cancel erase: By pressing the current faults will appear again. 9. Turn ignition OFF to end test.

Diagnostic trouble code (DTC) N22	Possible cause	Test step/Remedy 1)
- -	No malfunction in system	-
	CAN communication	Wiring.
	In-car temperature sensor (B10/4)	23 4.0
	Outside temperature indicator temperature sensor (B14)	23 10.0
	Heater core temperature sensor (B10/1)	23 7.0
	Evaporator temperature sensor (B10/6)	23 5.0
	ECT sensor (B11/4 )	23 10.0
	Refrigerant pressure sensor (B12)	23 8.0
	Refrigerant temperature sensor (B12/1)	23 6.0
	Refrigerant fill	23 8.0 , 6.0
	Coolant circulation pump (A31m1)	23 14.0
	Left-side water valve (Y21y1)	23 15.0
	Right-side water valve (Y21y2)	23 15.0
	Electromagnetic clutch (A9k1)	23 17.0
	Idle speed increase	-
	Pulse module (N65)	23 11.0
	Serial interface (K1)	23 10.0
	Diverter flap (Y11/3)	23 20.0
	Blend air flap (Y11/3)	23 21.0
	Fresh/recirculated airflap (Y11/3) (long stroke)	23 24.0
	Fresh/recirculated airflap (Y11/3) (short stroke)	23 25.0
	Defroster outlet flap (Y11/3) (long stroke)	23 18.0
	Defroster outlet flap (Y11/3) (short stroke)	23 19.0
	Footwell flap (Y11/3) (long stroke)	23 22.0
	Footwell flap (Y11/3) (short stroke)	23 23.0
	Serial interface (K2)	23 11.0
	Wide open throttle (WOT) signal diesel engines	-

1) Observe Preparation for Test, see 22 .