Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Climate Control Unit Inputs and Outputs
2008 Acura CSX Base, K20A3SECTION Climate Control Unit Inputs and Outputs
WARNING: This page is about a different car, the 2011 Acura TL, 2010 Acura TL, and 2009 Acura TL. However, it is still accessible from the selected car via links, so may be relevant.
CONNECTOR A
TERMINALS DESCRIPTION
| Cavity | Wire color | Terminal name | Description | Signal |
|---|---|---|---|---|
| 1 | BLK | GND | Climate control unit ground (G403) | Less than 0 5 V at all times |
| 3 | RED | DISP CLK | Inputs clock signal from Audio-HVAC display | With ignition switch ON (II), or vehicle in ON mode pulses (about 2 5V) |
| 4 | PUR | DISP SO | Outputs display data to Audio-HVAC display | With ignition switch ON (II), or vehicle in ON mode pulses (about 2 5 V) |
| 5 | BLU | M-DEF (Ps) | Drives passenger's mode control motor to DEF | With ignition switch ON (II), or vehicle in ON mode, and motor moving to DEF battery voltage |
| 6 | GRY | M-VENT (Ps) | Drives passenger's mode control motor to VENT | With ignition switch ON (II), or vehicle in ON mode, and motor moving to VENT battery voltage |
| 7 | GRY | M-DEF (Dr) | Drives driver's mode control motor to DEF | With ignition switch ON (II), or vehicle in ON mode, and motor moving to DEF battery voltage |
| 8 | WHT | M-VENT (Dr) | Drives driver's mode control motor to VENT | With ignition switch ON (II), or vehicle in ON mode, and motor moving to VENT battery voltage |
| 9 | LT BLU | M-COOL (Ps) | Drives passenger's air mix control motor to COOL | With ignition switch ON (II), or vehicle in ON mode, and motor moving to COOL battery voltage |
| 10 | LT GRN | M-HOT (Ps) | Drives passenger's air mix control motor to HOT | With ignition switch ON (II), or vehicle in ON mode, and motor moving to HOT battery voltage |
| 11 | LT BLU | M-COOL (Dr) | Drives driver's air mix control motor to COOL | With ignition switch ON (II), or vehicle in ON mode, and motor moving to COOL battery voltage |
| 12 | PNK | M-HOT (Dr) | Drives driver's air mix control motor to HOT | With ignition switch ON (II), or vehicle in ON mode, and motor moving to HOT battery voltage |
| 15 | LT GRN | IG2 | IG2 power supply | With ignition switch ON (II), or vehicle in ON mode battery voltage |
| 17 | GRN | MODE 1 (Ps) | Passenger's mode control motor position feedback | With ignition switch ON (II), or vehicle in ON mode about 0 V or about 5 V (depending on motor position) |
| 18 | BRN | MODE 2 (Ps) | Passenger's mode control motor position feedback | With ignition switch ON (II), or vehicle in ON mode about 0 V or about 5 V (depending on motor position) |
| 19 | BLU | MODE 3 (Ps) | Passenger's mode control motor position feedback | With ignition switch ON (II), or vehicle in ON mode about 0 V or about 5 V (depending on motor position) |
| 20 | LT GRN | MODE 4 (Ps) | Passenger's mode control motor position feedback | With ignition switch ON (II), or vehicle in ON mode about 0 V or about 5 V (depending on motor position) |
| 21 | LT GRN | MODE 1 (Dr) | Driver's mode control motor position feedback | With ignition switch ON (II), or vehicle in ON mode about 0 V or about 5 V (depending on motor position) |
| 22 | BRN | MODE2 (Dr) | Driver's mode control motor position feedback | With ignition switch ON (II), or vehicle in ON mode about 0 V or about 5 V (depending on motor position) |
| 23 | YEL | MODE 3 (Dr) | Driver's mode control motor position feedback | With ignition switch ON (II), or vehicle in ON mode about 0 V or about 5 V (depending on motor position) |
| 24 | BLU | MODE 4 (Dr) | Driver's mode control motor position feedback | With ignition switch ON (II), or vehicle in ON mode about 0 V or about 5 V (depending on motor position) |
| 25 | GRY | AMD-P (Dr) | Driver's air mix control motor position feedback | With ignition switch ON (II), or vehicle in ON mode between 0 5 V and 4 5 V (depending on motor position) |
| 26 | YEL | AMD-P (Ps) | Passenger's air mix control motor position feedback | With ignition switch ON (II), or vehicle in ON mode between 0 5V and 4 5V (depending on motor position) |
| 27 | BLU | BLW-V | Feedback of power transistor drain voltage | With ignition switch ON (II), or vehicle in ON mode, and fan switch OFF about 8 V Voltage decreases as fan speed increases |
| 28 | YEL | BLW-G | Outputs power transistor gate voltage | With ignition switch ON (II), or vehicle in ON mode, and fan switch at MIN about 2 V Voltage increases to about 10 V with fan switch at MAX |
| 30 | GRY | ILL + | Power source for illumination | With combination light switch ON battery voltage |
CONNECTOR B
TERMINALS DESCRIPTION
| Cavity | Wire color | Terminal name | Description | Signal |
|---|---|---|---|---|
| 1 | RED | Rr DEF LED | Switches rear window defogger/mirror defogger button LED ON/OFF | - |
| 2 | PNK | DEF LED | Switches defroster button LED ON/OFF | - |
| 3 | LT BLU | PS IND PWM | Inputs indicator LED PWM (Pulse Width Modulation) control signal | - |
| 5 | PUR | PS IN 1 | Inputs AUTO button signal | - |
| 6 | WHT | PS IN 2 | Inputs passenger's temperature up button signal | - |
| 7 | YEL | PS IN 3 | Inputs passenger's temperature down button signal | - |
| 8 | BRN | PS IN 4 | Inputs passenger's MODE button signal | - |
| 9 | GRN | PS IN 5 | Inputs rear window defogger/mirror defogger button signal | - |
| 10 | GRY | PS IN 6 | Inputs A/C button signal | - |
| 11 | BLU | PS IN 7 | Inputs recirculation button signal | - |
| 12 | LT GRN | PS IN 8 | Inputs defroster button signal | - |
| 13 | PUR | SYNC LED | Switches SYNC button LED ON/OFF | - |
| 14 | ORN | FR LED | Switches recirculation button LED ON/OFF | - |
| 15 | WHT | DR IND PWM | Inputs indicator LED PWM (Pulse Width Modulation) control signal | - |
| 17 | BRN | DR IN 1 | Inputs AUTO button signal | - |
| 18 | GRN | DR IN 2 | Inputs driver's temperature up button signal | - |
| 19 | GRY | DR IN 3 | Inputs driver's temperature down button signal | - |
| 20 | BLU | DR IN 4 | Inputs driver's MODE button signal | - |
| 21 | LT GRN | DR IN 5 | Inputs SYNC button signal | - |
| 22 | ORN | DR IN 6 | Inputs FAN up button signal | - |
| 23 | PNK | DR IN 7 | Inputs FAN down button signal | - |
| 24 | RED | DR IN 8 | Inputs FAN ON/OFF button signal | - |
CONNECTOR C
TERMINALS DESCRIPTION
| Cavity | Wire color | Terminal name | Description | Signal |
|---|---|---|---|---|
| 1 | RED | S-COM | Ground for sensors | Less than 0 5 V at all times |
| 2 | BRN | S5V | Power source for sensors | With ignition switch ON (II), or vehicle in ON mode about 5 V |
| 4 | ORN | AC SI | Outputs NAVI communication data | With ignition switch ON (II), or vehicle in ON mode pulses (about 2 5 V) |
| 5 | PUR | AC SO | Inputs NAVI communication data | With ignition switch ON (II), or vehicle in ON mode pulses (about 2 5 V) |
| 6 | BRN | AC CLK | Inputs clock signal from NAVI | With ignition switch ON (II), or vehicle in ON mode pulses (about 2 5 V) |
| 7 | BLU | CAN-LO | B-CAN communication line | With ignition switch ON (II), or vehicle in ON mode pulses (about 2 5 V) |
| 8 | PNK | CAN-HI | B-CAN communication line | With ignition switch ON (II), or vehicle in ON mode pulses (about 2 5 V) |
| 9 | PUR | FRS | Drives recirculation control motor to FRESH | With ignition switch ON (II), or vehicle in ON mode, and motor moving to FRESH battery voltage |
| 10 | ORN | REC | Drives recirculation control motor to RECIRCULATE | With ignition switch ON (II), or vehicle in ON mode, and motor moving to RECIRCULATE battery voltage |
| 11 | YEL | Pd | A/C pressure sensor signal | With engine running and A/C compressor clutch engaged about 1 4-4 8 V (depending on A/C pressure) |
| 12 | YEL | Hum | Inputs humidity sensor signal | With ignition switch ON (II), or vehicle in ON mode between 10V and 4 0V (depending on humidity) |
| 14 | PUR | Tsum | Inputs sunlight sensor signal | With ignition switch ON (II), or vehicle in ON mode, and vehicle in direct sunlight Less than 3 5V Voltage rises above 3 6V when vehicle is out of direct sunlight |
| 15 | LT BLU | Tr | Inputs in-car sensor signal | With ignition switch ON (II), or vehicle in ON mode between 10V and 4 0V (depending on in-car temperature) |
| 16 | BRN | Teva | Inputs evaporator temperature sensor signal | With ignition switch ON (II), or vehicle in ON mode between 10V and 4 0V (depending on evaporator temperature) About 2 5 V at 72°F (22°C) |
| 17 | WHT | Tarn | Inputs outside air temperature sensor signal | With ignition switch ON (II), or vehicle in ON mode between 10 V and 4 0 V (depending on ambient temperature) |
| 18 | GRN | MODE1 | Recirculation control motor position feedback 1 signal | With ignition switch ON (II), or vehicle in ON mode about 0 V or about 5 V (depending on motor position) |
| 19 | BLU | MODE 2 | Recirculation control motor position feedback 2 signal | With ignition switch ON (II), or vehicle in ON mode about 0 V or about 5 V (depending on motor position) |
| 20 | ORN | MODE 3 | Recirculation control motor position feedback 3 signal | With ignition switch ON (II), or vehicle in ON mode about 0 V or about 5 V (depending on motor position) |
RENDER: 1.0x
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.