Signal descriptions MCC
Note. A manual climate control unit may or may not be equipped with air conditioning (A/C) system.
Connector A; A1-6
All values listed below should be measured between the respective terminal in column 1 ( Terminal ) and termnal B16 (ground) unless stated otherwise in column 4 ( Other ).
Scheme 148
The control module terminals in connector A are not connected to the breakout box.
Note. It is important to check ground terminals before taking readings.
| U= | DC voltage in volts (V) | F= | Frequency in Hertz (Hz) |
|---|---|---|---|
| Ulow= | Voltage approx 0 V | ||
| Ubat= | Battery voltage |
| Terminal. | Signal type | Ignition on/engine idling | Other |
|---|---|---|---|
| A1 | Control signal, blower fan speed 1 blower fan motor (via power resistor). | Positions 1, 2, 3, 4, 5: Ubat Position 0: Ulow | Position 0: No blower fan speed. Position 5: Maximum blower fan speed. |
| A2 | Control signal, blower fan speed 2 blower fan motor (via power resistor). | Positions 2, 3, 4, 5: Ubat Position 0: Ulow In other positions displays other values. | |
| A3 | Control signal, blower fan speed 4 blower fan motor (via power resistor). | Positions 4, 5: Ubat Position 0: Ulow In other positions displays other values. | |
| A4 | X supply (from ignition switch position I and II). | Ubat | |
| A5 | Control signal, blower fan speed 3 blower fan motor (via power resistor). | Positions 3, 4, 5: Ubat Position 0: Ulow In other positions displays other values. | Position 0: No blower fan speed. Position 5: Maximum blower fan speed. |
| A6 | Control signal, blower fan speed 5 blower fan motor (via power resistor). | Position 5: Ubat Position 0: Ulow In other positions displays other values. |
Note. A manual climate control unit may or may not be equipped with air conditioning (A/C) system.
Connector B; B1-22
All values listed below should be measured between the respective terminal in column 1 ( Terminal ) and termnal B16 (ground) unless stated otherwise in column 4 ( Other ).
Scheme 149
The MCC control module connector # B1-22 is the equivalent of # 31-53 on the breakout box.
Note. It is important to check ground terminals before taking readings. Connect breakout box according to Connection of breakout box MCC before readings are taken.
| U= | DC voltage in volts (V) | F= | Frequency in Hertz (Hz) |
|---|---|---|---|
| Ulow= | Voltage approx 0 V | %duty= | Duty cycle (pulse ratio) as a percentage (%) |
| Ubat= | Battery voltage |
| Terminal. | Signal type | Ignition on/engine idling | Other |
|---|---|---|---|
| B1 | Ground, damper motor position sensor recirculation. | Uapprox.0.3 V. | |
| B2 | Power supply, damper motor position sensor recirculation. | U=4.8-5.2 V | |
| B3 | Signal, damper motor position sensor recirculation. | U=0-5 V. Recirculation disengaged: Uapprox.1.9 V. Recirculation engaged: Uapprox.4.2 V. | Voltage increases when recirculation engaged. |
| B4 | Control signal+, damper motor recirculation. | Motor's +winding activated: U=2-4 V below Ubat. Motor -winding not activated: U less than 1 V. | Activated when recirculation disengaged |
| B5 | Control signal+, damper motor recirculation. | Motor's +winding activated: U=2-4 V below Ubat. Motor -winding not activated: U less than 1 V. | Activated when recirculation engaged |
| B6 | Power supply, X supply (from ignition switch position I and II) | Ubat | |
| B7 | |||
| B8 | |||
| B9 | |||
| B10 | |||
| B11 | Ground, damper motor position sensor air distribution. | Uapprox.0.3 V. | |
| B12 | Power supply, damper motor position sensor air distribution. | U=4.8-5.2 V | |
| B13 | Signal, damper motor position sensor air distribution. | U=0-5 V. | The voltage varies with position of the damper motor. |
| B14 | Control signal+, damper motor air distribution. | Motor's +winding activated: U=2-4 V below Ubat. Motor -winding not activated: U less than 1 V. | Motor can be activated by turning the air distribution selector. |
| B15 | Control signal+, damper motor air distribution. | Motor's +winding activated: U=2-4 V below Ubat. Motor -winding not activated: U less than 1 V. | Motor can be activated by turning the air distribution selector. |
| B16 | Ground (measured against battery negative terminal) | Ulow | |
| B17 | 30 supply (from battery) | Ubat | |
| B18 | Signal; panel lighting (from rheostat) | Fapprox.125 Hz. Increased duty cycle (+trigg) gives brighter lighting level. | Signal is a pulsed signal with fixed frequency and variable duty cycle. |
| B19 | |||
| B20 | |||
| B21 | |||
| B22 | Signal, request air conditioning (A/C) compressor. (To engine control module (ECM)) (Only on cars with air conditioning (A/C)) | A/C REQUEST: Uapprox.1-2approx.V below Ubat No request: U less than 1.5 V. |