HVAC Control Unit Inputs and Outputs
WARNING: This page does not describe the selected car, but rather 10 other vehicles, including the 2009 Honda S2000, 2008 Honda S2000, 2007 Honda S2000, 2006 Honda S2000, and 2005 Honda S2000. However, it is still accessible from the selected car via links, so may be relevant.
HVAC CONTROL UNIT REFERENCE
| Cavity | Wire color | Terminal name | Description | Signal |
|---|---|---|---|---|
| 1 | PNK | M-COOL | Drives air mix control motor to COOL | With ignition switch ON (II) and air mix control motor moving to COOL: battery voltage |
| 2 | PNK/BLU | M-HOT | Drives air mix control motor to HOT | With ignition switch ON (II) and air mix control motor moving to HOT: battery voltage |
| 3 | YEL/BLU | M-DEF | Drives mode control motor to DEF | With ignition switch ON (II) and mode control motor moving to DEF: battery voltage |
| 4 | YEL/RED | M-VENT | Drives mode control motor to VENT | With ignition switch ON (II) and mode control motor moving to VENT: battery voltage |
| 5 | GRY | S5V | Sensor 5 V output | With ignition switch ON (II): about 5 V |
| 6 | PNK/BLK | AMD-P | Detects air mix control motor position | With ignition switch ON (II) and air mix door at HOT: about 4.5 V With ignition switch ON (II) and air mix door at COOL: about 1.5V |
| 7 | BRN | Teva | Evaporator temperature sensor input | With ignition switch ON (II): between 1.0 V and 4.0 V depending on evaporator temperature. About 2.5 V at 72°F (22 °C). |
| 8 | YEL/GRN | MODE 2 | Mode control motor signal 2 | With ignition switch ON (II): about 5 V or about 0 V, depending upon mode |
| 9 | BRN/WHT | MODE 1 | Mode control motor signal 1 | With ignition switch ON (II) about 5 V or about 0 V, depending upon mode |
| 10 | LT GRN | S-COM | Sensor ground | Less than 0.5 V at all times |
| 11 | BLU/RED | BLW-V | Power transistor feedback | With ignition switch ON (II) and blower OFF: between 5 V and 12 V. Voltaqe decreases as blower speed increases |
| 12 | BLU/WHT | ACS | A/C compressor ON request | With ignition switch ON (II), A/C pressure switch closed, and A/C request OFF: battery voltage. When A/C request switches ON, voltage changes to about 0 V. |
| 13 | BLU/YEL | BLW-G | Power transistor control output | With ignition switch ON (II) and blower OFF: 0 V. Voltage increases as blower speed increases |
| 15 | GRN/WHT | FRS | Drives the recirculation control motor to FRESH | With ignition switch ON (II) with motor moving to FRESH: battery voltage |
| 16 | GRN/YEL | REC | Drives the recirculation control motor to REC | With ignition switch ON (II) with motor moving to REC: battery voltage |
| 21 | YEL | MODE 4 | Mode control motor signal 4 | With ignition switch ON (II) about 5 V or about 0 V, depending upon mode |
| 22 | BLK/WHT | MODE 3 | Mode control motor signal 3 | With ignition switch ON (II) about 5 V or about 0 V, depending upon mode |
| 23 | BLK/WHT | Illumination cancel signal from gauge control module | ||
| 26 | BLK | GND | Ground for heater control panel | Less than 0.5 V at all times |
| 27 | RED/BLK | ILL+ | Power source for illumination | With ignition switch ON (II): battery voltage |
| 28 | RED | ILL- | Ground for illumination | With combination light switch ON: voltage decreases as dash light brightness increases |
| 29 | WHT/RED | +B | Battery power source | Battery voltage at all times |
| 30 | BLK/YEL | IG2 | IG2 power source | With ignition switch ON (II): battery voltage |