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. Numerous DTC's can also be read with the Hand-Held Tester (HHT).
		P83.40-2110-01

Preparations for DTC Readout 1. Review 11, 12 , 13 , 14 , 15 , 21 , 22 , 31 , 32 , 41 , 2. Ignition: ON 3. Temperature selector: left: ; right: 4. Ignition: OFF 5. Ignition: ON 6. Within 20 seconds press and simultaneously for more than 5 seconds. 7. The LED in flashes and the display shows . 8. Press repeatedly until all DTC's are displayed. Record each DTC as it is displayed. 9. Each fault (short circuit, open circuit) is assigned a DTC. Thus in the left display: " " appears, and the right display indicates the DTC. 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. By pressing the right the next DTC is displayed. 10. To erase: Can only be performed after all faults have been readout. Press left and right buttons simultaneously for more than 2 seconds and the display shows: left: "d" and right: "FF". To cancel erase: By pressing the left button, the current faults will appear again. 11. Select a base temperature setting. 12. Turn ignition OFF, to end test. Due to instrument cluster (IC) series interface, DTC's may be stored in IC memory, therefore readout and erase DTC's from IC memory.

Diagnostic trouble code (DTC) N22	Possible cause	Test step/Remedy 1)
- -	No malfunction in system	-
	In-car temperature sensor (B10/4) Model 208.465: With the soft top down, the power soft top control module (N52) will override B10/4 and in this case, the DTC will not be stored in memory.	23 4.0
	Outside temperature indicator temperature sensor (B14)	23 11.0
	Heater core temperature sensor (B10/1) (left)	23 7.0
	Heater core temperature sensor (B10/1) (right)	23 7.0
	Evaporator temperature sensor (B10/6)	23 5.0
	ECT sensor (B11/4 )	23 11.0
	Refrigerant pressure sensor (B12)	23 9.0
	Refrigerant temperature sensor (B12/1)	23 6.0
	Refrigerant fill level	23 9.0 , 6.0
	Coolant circulation pump (M13)	23 15.0
	Left-side water valve (Y21y1)	23 16.0
	Right-side water valve (Y21y2)	23 16.0
	Electromagnetic clutch (A9k1)	23 18.0
	Idle speed increase	-
	AIR control module (N65/1)	23 12.0
	Serial interface K1	23 11.0 , 21 (CAN)
	Switchover flap (Y11)	23 19.0
	Non-USA Test Step	-
	Serial interface K2	23 12.0 , 21 (CAN)

1) Observe Preparation for Test, see 22 .