LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Acura >> 2012 >> TL Base >> Repair and Diagnosis (Single Page) >> Heating, Ventilation & A/C (HVAC) >> HVAC Control Systems >> Climate Control >> System Description >> Climate Control Unit Inputs and Outputs
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Climate Control Unit Inputs and Outputs

Fig 1: Identifying Climate Control Unit A (32P) Connector End View
G08070948Courtesy of AMERICAN HONDA MOTOR CO., INC.
CONNECTOR A

Cavity Wire color Terminal name Description Signal
1 BLK GND Climate control unit ground (G403) Less than 0.2 V at all times
3 RED DISP CLK Inputs clock signal from audio-HVAC display unit With ignition switch ON (II), or vehicle in ON mode: pulses
4 PUR DISP SO Outputs display data to audio-HVAC display unit With ignition switch ON (II), or vehicle in ON mode: pulses
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 MODE 2 (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 1.0 V and 4.0 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 1.0 V and 4.0 V (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
Fig 2: Identifying Climate Control Unit B(24P) Connector End View
G08070949Courtesy of AMERICAN HONDA MOTOR CO., INC.
CONNECTOR B

Cavity Wire color Terminal name Description Signal
1 RED RrDEF 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 IN1 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 air conditioning 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 R/F 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 ON/OFF button signal - -
Fig 3: Identifying Climate Control Unit C (20P) Connector End View
G08070950Courtesy of AMERICAN HONDA MOTOR CO., INC.
CONNECTOR C

Cavity Wire color Terminal name Description Signal
1 RED SENS-COM Ground for sensors Less than 0.2 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(1) ORN NAVI SI Outputs NAVI communication data from audio-navigation unit With ignition switch ON (II), or vehicle in ON mode: pulses
5(1) PUR NAVI SO Inputs NAVI communication data from audio-navigation unit With ignition switch ON (II), or vehicle in ON mode: pulses
6(1) BRN NAVI CLK Inputs clock signal from audio-navigation unit With ignition switch ON (II), or vehicle in ON mode: pulses
7 BLU B-CAN L B-CAN communication line With ignition switch ON (II), or vehicle in ON mode: pulses
8 PNK B-CAN H B-CAN communication line With ignition switch ON (II), or vehicle in ON mode: pulses
9 PUR M-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 M-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 0.7-4.5 V (depending on A/C pressure)
12 YEL Hum Inputs humidity sensor signal With ignition switch ON (II), or vehicle in ON mode: about 1.0-4.0 V (depending on humidity)
14 PUR Tsun Inputs sunlight sensor signal With ignition switch ON (II), or vehicle in ON mode, and vehicle in direct sunlight: Less than 3.56 V. Voltage rises above 3.56 V 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: about 1.0-4.0 V (depending on in-car temperature)
16 BRN Teva Inputs evaporator temperature sensor signal With ignition switch ON (II), or vehicle in ON mode: about 1.0-4.0 V (depending on evaporator temperature)
17 WHT Tarn Inputs outside air temperature sensor signal With ignition switch ON (II), or vehicle in ON mode: about 1.0-4.0 V (depending on ambient temperature)
18 GRN MODE 1 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)
(1) With navigation