Automatic Climate Control (ACC) Service Menus
Back to: WIS 83.40 Automatic Climate Control (ACC) or Heating Ventilation and Air Conditioning (HVAC)
Description - ACC Service Menus
There are three hidden menus available in the W220 Auto Climate Control (ACC) which are used to:
- Access/Review/Read Auto Climate Control (ACC) Actual Parameter Values,
- ACC Flap/Vent, Engine Fan and A/C Compressor Test, and
- access/review/read and clear/reset Fault/Error Diagnostic Trouble Codes (DTC).
Hidden Menus Summary - ACC Service Menus
Access/Review/Read Auto Climate Control (ACC) Actual Parameter Values
- This Menu allows an access/review/read of the Auto Climate Control (ACC) actual parameter values during normal operation.
- For example the actual temperature sensed by various sensors can be reviewed and the amount of opening of various flaps as determined by the Auto Climate Control (ACC) Module can be monitored.
- Some controls may be varied in real time and the result monitored via this Menu, eg moving the Centre Vent (N18/4) Centre Potentiometer results in Parameter NR.28: changing value from 0% – 100%.
ACC Flap/Vent, Engine Fan and A/C Compressor Test
- This menu allows testing of the Auto Climate Control (ACC) Flaps/Vents/Outlets and the operation of the Engine Coolant Fan and the A/C Compressor.
- For example, each electrically operated Flap/Vent/Outlet can be exercised through its full range of operation whilst subjectively or objectively monitoring the resulting effect on the Auto Climate Control (ACC) air flow and/or output temperature.
- Test Parameter NR.12: allows the Engine Coolant Electric Suction Fan (M4/3) to be tested through most of its operational range; Off, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, On. Note the engine must be running for this test and hence the fan may not be set to ‘Off’.
- Similarly, Test Parameter NR.13: allows the A/C Compressor to be tested by varying its Capacity from; Off, 1%, 2%, 3% up to 98%, 99%, On.
| Nr | Legend | Comment | |
|---|---|---|---|
| 00 | In Car Temperature Sensor (N22/b1), ACC Pushbutton Control Module (N22) Front Compartment | ||
| 01 | In Car Temperature Sensor (N70b1), Overhead Control Panel (OCP) (N70) | ||
| 02 | Outside/Ambient Temperature Sensor (B14) | ||
| 03 | Heater Core Temperature Sensor Left (B10/2) Front Compartment | ||
| 04 | Heater Core Temperature Sensor Right (B10/3) Front Compartment | ||
| 05 | Evaporator Core Temperature Sensor (B10/6) Front Compartment | ||
| 06 | Engine Coolant Temperature Sensor (B11/4) | ||
| 07 | Refrigerant (R134A) Pressure Sensor (B12) | Value: 7,5 bar (Stand-by) – about 16 bar (A/C on) TBC | |
| 08 | Refrigerant (R134A) Temperature Sensor (B12/1) | ||
| 09 | L Unter {Under} Kümlung {??} Kühlung {Cooling} and possibly L Unterkühlung {Cooling Lower} also L Unterkuehlung {degrees the refrigerant is cooled before it exits the condenser} | ||
| 10 | Blower Control Voltage, Front Compartment | Possible values: 1.2, 1.5, 1.8, 2.1, 2.4, 3.0, 3.8 and 6.0 volts. Maps respectively to values 1, 2, 3, 4, 5, 6, 7 in ACC Display Bars. | |
| 11 | 4 Quadrant Sun Sensor (B32/2) Front Left | Value: 0% – 125% | |
| 12 | 4 Quadrant Sun Sensor (B32/2) Front Right | Value: 0% – 125% | |
| 13 | 4 Quadrant Sun Sensor (B32/2) Rear Right | Value: 0% – 125% | |
| 14 | 4 Quadrant Sun Sensor (B32/2) Rear Left | Value: 0% – 125% | |
| 15 | Average Insolation | Value: 0% – 125% | |
| 16 | Multi-function Sensor, Carbon Monoxide (CO) (B31/1) | Value: 0 – 1023 | |
| 17 | Multi-function Sensor, Nitrous Oxide (NOx) (B31/1) | Value: 0 – 1023 | |
| 18 | Multi-function Sensor, Dew Point Temperature (B31/1) | ||
| 19 | Max Unter {Under} Kümlung {??} Kühlung {Cooling} and possibly Max Unterkühlung {Cooling Lower} also Max Unterkuehlung {degrees the refrigerant is cooled before it exits the condenser} | ||
| 20 | Engine Coolant Electric Suction Fan (M4/3) Rotation. | Actual percentage of maximum RPM as demanded by the control unit. At high speeds the fan may be freewheeling with 0% electrical demand. Value: 0% – 100% | |
| 21 | Engine Speed | Value in RPM | |
| 22 | Ground Speed | ||
| 23 | Bel. Most likely an abbrev. for Beleuchtung {Illumination, Lighting} Dimmung {Dimming} | ||
| 24 | Battery Voltage | ||
| 25 | Not Used | ||
| 26 | Not Used | ||
| 27 | Centre Vent (N18/4) Left Potentiometer Front Compartment | Value: 0% – 100% | |
| 28 | Centre Vent (N18/4) Centre Potentiometer Front Compartment | Value: 0% – 100% | |
| 29 | Centre Vent (N18/4) Right Potentiometer Front Compartment | Value: 0% – 100% | |
| 30 | Heat Exchanger Air Temperature Left, Rear Passenger Compartment (B10/9) | ||
| 31 | Heat Exchanger Air Temperature Right, Rear Passenger Compartment (B10/10) | ||
| 32 | Evaporator Core Temperature Sensor, Rear Passenger Compartment (B10/11) | ||
| 33 | Blower Control Voltage, Rear Passenger Compartment | ||
| 34 | Specified Temperature Left, Rear Passenger Compartment (N22/4) | ||
| 35 | Specified Temperature Right, Rear Passenger Compartment (N22/4) | ||
| 36 | TBD | ||
| 37 | TBD | ||
| 38 | Built NR KLA | ||
| 39 | Not Used | ||
| 40 | Defroster Outlet Flap Left (M16/13) (#7) | Value: ZU (closed), 0% – 100%, AUF (open) | |
| 41 | Defroster Outlet Flap Right (M16/14) (#7) | Value: ZU (closed), 0% – 100%, AUF (open) | |
| 42 | Footwell Flap Left (M16/15) (#11) Front Compartment | Value ZU (closed), 0% – 100%, AUF (open) | |
| 43 | Footwell Flap Right (M16/16) (#11) Front Compartment | Value: ZU (closed), 0% – 100%, AUF (open) | |
| 44 | Centre Outlet Temperature Regulating Blend Flap Left (M16/19) (#5) | Value: ZU (closed), 0% – 100%, AUF (open) | |
| 45 | Centre Outlet Temperature Regulating Blend Flap Right (M16/20) (#5) | Value: ZU (closed), 0% – 100%, AUF (open) | |
| 46 | Centre Outlet Diverter Flap Left (M16/17) (#4) | Value: ZU (closed), 0% – 100%, AUF (open) | |
| 47 | Centre Outlet Diverter Flap Right (M16/18) (#4) | Value: ZU (closed), 0% – 100%, AUF (open) | |
| 48 | Fresh Air (#1) and Recirculated Air (#2) Flaps (M16/21) | These Flaps operate as a pair. Value: Frischl. {Fresh Air}, 70%, Umluft {Recirculate} | |
| 49 | Aktivkohle Filter (AKF) {Activated Charcoal Filter (ACF)} (A32m2) (#3) | LED Value: AUS {OFF}, EIN {ON}. Bypass Flap Value: AUS {Open}, EIN {Closed} | |
| 50 | ACC Software Version | ||
| 51 | ACC Hardware Version | ||
| 52 | Optional Rear A/C Control Panel (N22/4) Software Version | ||
| 53 | Optional Rear A/C Control Panel (N22/4) Hardware Version | ||
| 54 | Stepper Motor Unit (N22/5) Software Version | ||
| 55 | Stepper Motor Unit (N22/5) Hardware Version | ||
| 56 | Centre Vent Control Module (N18/4) Software Version | ||
| 57 | Centre Vent Control Module (N18/4) Hardware Version | ||
| 58 | Multi-function Sensor (B31/1) Software Version | ||
| 59 | Multi-function Sensor (B31/1) Hardware Version | ||
| 60 | 4 Quadrant Sun Sensor (B32/2) Software Version | ||
| 61 | 4 Quadrant Sun Sensor (B32/2) Hardware Version | ||
| 62 | Regel {Rule} or possibly Regler {Control} Offset {Offset} | ||
| 63 | Gebl {Fan} Offset {Offset} | ||
| 64 | Not Used | ||
| 65 | Not Used | ||
| 66 | Not Used | ||
| 67 | Not Used | ||
| 68 | Not Used | ||
| 69 | Tunnel Mode | Press either Recirc. or ACF switch for greater than 5 secs. Closes all Windows and Sliding Tilting Roof. Value: automat. {automatic}, and TBD. See Section 12.2.19 Automatic lowering for convenience closing (tunnel mode switching) (NR.69:) | |
| 70 | Follst {??}. Kontr {Control} | Value: aktiv {active}, and TBD | |
| 71 | UL Umluft {Recirculate} Logik {Logic} Aktivkohle Filter (AKF) {Activated Charcoal Filter (ACF)} | Pollution-dependent recirculated air circuit -Inactive, -Active (with activated charcoal filter) Standard, -Active (without activated charcoal filter) Active (with activated charcoal filter). Value: aktiv {active}, inaktiv {inactive}. See Section 12.2.5 Pollutant-dependent switchover to recirculated air (NR.71:) | |
| 72 | UL Umluft {Recirculate} Logik {Logic} GEN {??} | ||
| 73 | Tunnel Funktion {Tunnel Function} Convenience Locking (Tunnel Shift) | Value: aktiv {active}, inaktiv {inactive}. See Section 12.2.6 Convenience closing (tunnel circuit) (NR.73:) | |
| 74 | Gebläse Balken {Fan Beam} Beam indicator for blower in automatic mode | ACC bar display for blower in automatic mode. ”Display” and “Do not display”. Value: generell {general}, and TBD. See Section 12.2.7 Bar display for blower in automatic mode (NR.74:) | |
| 75 | Reheat Modus {Reheat Mode} Standard and icing protection | Value: aktiv {active}, inaktiv {inactive}. See Section 12.2.8 REHEAT mode (NR.75:) | |
| 76 | Umluft Manuell {Manual Fan Recirculate} | Value: zeitbegr. {??}, and TBD. For a 171.456 vehicle "Manual recirculated air control". Options are: LIMITED: After a certain time, the recirculated
air flap will open again slightly to prevent the oxygen concentration in the air dropping. UNLIMITED: The recirculated air flap always remains 100% closed. Warning: After a time, the oxygen concentration in the interior air will drop because no fresh air is coming in. | |
| 77 | Display Readout for ACC display: night design | Value: gen. neg. {negative display} automat. {automatic}. See Section 12.2.9 Readout in display: night design (NR.77:) | |
| 78 | Heissland {Hot Country}. National version for Air Conditioner: Remaining World or Hot Countries. | Value: aktiv {active}, inaktiv {inactive}. See Section 12.2.2 National version climate control (NR.78:) | |
| 79 | Maxcool | Value aktiv {active}, inaktiv {inactive}. ACTIVATED: In automatic mode, the message "MAX COOL" appears in the display if high cooling output is requested. DEACTIVATED: Message "MAX COOL" is never shown. | |
| 80 | Display Readout for ACC display: day design | Value: automat. {automatic}, ?? {positive display}. See Section 12.2.10 Readout in display: day design (NR.80:) | |
| 81 | Abspeicherung {Storage}. Key responsive storage of ACC settings. | Value: Schlüssel {Key}, and TBD. Each remote control key stores ACC settings. See 12.2.11 Section Key-responsive storing of AC settings (NR.81:) | |
| 82 | Schnellauf {High Speed} | Value: aktiv {active}, inaktiv {inactive} | |
| 83 | Umluft {Fan} 100% - 100% recirculated air mode is possible | Value: möglich {possible}, and not possible. See Section 12.2.12 100% recirculated air mode is possible (NR.83:) | |
| 84 | Gebl. {Fan} Reaktion {Response}. Immediate blower reaction when temperature is adjusted | Value: aktiv {active}, m.Sonne, and TBD. See Section 12.2.13 Immediate blower reaction when temperature is adjusted (NR.84:) | |
| 85 | Grundeinstell {Basic Service}. Possibly Automatic basic setting for rear air conditioning TBC | Value: automat. {automatic}, inaktiv{inactive}. See Section 12.2.14 Automatic basic setting Rear air conditioning (NR.85:) | |
| 86 | UL-KL. Bei {??} "0". UL Umluft {Recirculate} Position of main air flap (ie Recirculated Air Flap with ACC switched off) | Value: geschl. {closed}, and open. See Section 12.2.15 Recirculated air flap with automatic air conditioning switched off (NR.86:) | |
| 87 | Grundbelöftung {Basic Ventilation}. Possibly electric engine coolant fan TBC | Value: aktiv {active}, and TBD. See Section 12.2.16 Suction fan control Basic fresh air flow (NR.87:) | |
| 88 | ESL 20 bar 100% | Value: aktiv {active}, and TBD | |
| 89 | ESL 20 bar 90% | Value: inaktiv {inactive}, and TBD | |
| 90 | ESL 18 bar 100% | Value: inaktiv {inactive}, and TBD | |
| 91 | ESL 18 bar 90% | Value: inaktiv {inactive}, and TBD | |
| 92 | ESL Gndbel. Grundbelöftung {Basic Ventilation} 25%. | Value: inaktiv {inactive}, aktiv {active}. Basic setting for electric engine coolant fan for vehicle speed < 70Km/h and air temperature > 15C. ACC may over-ride this value if required. See Section 12.2.18 Electric suction fan (NR.92: and NR.93:) | |
| 93 | ESL Gndbel. Grundbelöftung {Basic Ventilation} 40%. | Value: inaktiv {inactive}, aktiv {active}. Basic setting for electric engine coolant fan for vehicle speed < 70Km/h and air temperature > 15C. ACC may over-ride this value if required. See Section 12.2.18 Electric suction fan (NR.92: and NR.93:) | |
| 94 | Not Used | ||
| 95 | TBD | ||
| 96 | A/C Compressor Torque (Nm) | Value: 0 Nm – TBD Nm.This is an estimated value the ACC Controller sends to the ECU. The ACC delays the signal to the compressor a little bit and sends the desired torque value to the ECU. The ECU then informs the engine that there will be an additional torque applied. Thus any load shock to the engine by the compressor engaging is avoided. | |
| 97 | A/C Komp {Compressor} Stell {Capacity} | Value AUS {OFF} 0% – 100% | |
| 98 | A/C Compressor Valve DC Current (mA) | Value: 0 mA – 1000 mA | |
| 99 | Inner Regler {Internal Controls} | This is a weighted average from NR.00: and NR.01: which the ACC uses for a calculation of TBD. |
access/review/read and clear/reset Fault/Error Diagnostic Trouble Codes (DTC)
- To access/review/read the Automatic Climate Control (ACC) Fault/Error Diagnostic Trouble Codes (DTC) which are permanently stored in the ACC system, and to clear/reset/erase them from ACC memory.
- For example using the clear/reset/erase procedure you can unlock the Air Conditioner (A/C) compressor after recharging if you’ve run out of refrigerant gas.
DIY Access to Hidden Menus - ACC Service Menus
Be warned that accessing these hidden menus requires some technical experience.
Refer to W220 Automatic Climate Control Service Menu Version 4.pdf posted 2014-06-29 on BenzWorld. http://www.benzworld.org/forums/w220-s-class/1632652-w220-s-class-automatic-climate-control.html