Signal Descriptions MCC
WARNING: This page is about a different car, the 2002 Volvo C70, 2001 Volvo C70, 2000 Volvo C70, 1999 Volvo C70, and 1998 Volvo C70. However, it is still accessible from the selected car via links, so may be relevant.
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 terminal B16 (ground) unless stated otherwise in column 4 (Other ).
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. |
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| 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 terminal B16 (ground) unless stated otherwise in column 4 (Other ).
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. | U≈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: U≈1.9 V. Recirculation engaged: U≈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. | U≈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) |
f≈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: U≈1-2≈V below Ubat No request: U less than 1.5 V. |
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