LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Acura >> 2012 >> MDX >> Repair and Diagnosis >> Engine Performance >> System >> Fuel And Emissions Systems >> System Description >> PCM Inputs and Outputs at PCM Connector A (□) (49P)
April 5, 2026: LEMON Manuals is launched! Read the announcement.

PCM Inputs and Outputs at PCM Connector A (□) (49P)

Fig 1: Identifying PCM Inputs And Outputs At PCM Connector A (49P)
G08052429Courtesy of AMERICAN HONDA MOTOR CO., INC.
Terminal number Wire color Terminal name Description Signal
1 WHT VBSOL2 (POWER SOURCE FOR SOLENOID VALVES) Power source for solenoid valves With ignition switch ON (II): battery voltage
2 PNK SLS (SHIFT LOCK SOLENOID) Drives shift lock solenoid With ignition switch ON (II), in P, brake pedal pressed, and accelerator released: about 0 V
3 LT GRN STRLY (STARTER RELAY) Drives starter cut relay With ignition switch ON (II): about 0 V
4 WHT FANL (RADIATOR FAN CONTROL) Drives A/C condenser fan relay With condenser fan running: about 0 V
With condenser fan stopped: battery voltage
5 PUR FANH (RADIATOR FAN CONTROL) Drives radiator fan relay With radiator fan running: about 0 V
With radiator fan stopped or running at low speed: battery voltage
6 GRN MRLY (PGM-FI MAIN RELAY 1) Drives PGM-FI main relay 1 With ignition switch ON (II): about 0 V
With ignition switch in LOCK (0): battery voltage
7 BRN BKSWNC (BRAKE PEDAL POSITION SWITCH) Detects brake pedal position switch signal With ignition switch ON (II) and brake pedal released: battery voltage
With ignition switch ON (II) and brake pedal pressed: about 0 V
8 LT GRN BKSW (BRAKE PEDAL POSITION SWITCH) Detects brake pedal position switch signal With brake pedal released: about 0 V
With brake pedal pressed: battery voltage
9 BLK VG - (MASS AIR FLOW (MAF) SENSOR - SIDE) Ground for MAF sensor signal  
10 ORN ELD (ELECTRICAL LOAD DETECTOR (ELD)) Detects ELD signal With ignition switch ON (II): about 0.1-4.8 V (depending on electrical load)
11 BRN IMOFPR (IMMOBILIZER FUEL PUMP RELAY) Drives PGM-FI main relay 2 About 0 V for 2 seconds after turning ignition switch ON (II), then battery voltage
12 BLU MCS (ENGINE MOUNT CONTROL SOLENOID VALVE) Drives engine mount control solenoid valve At idle: about 0 V Above idle: battery voltage
13 RED ACC (A/C COMPRESSOR CLUTCH RELAY) Drives A/C compressor clutch relay With compressor ON: about 0 V
With compressor OFF: battery voltage
16(1) GRN ATPP (TRANSMISSION RANGE SWITCH P) Detects transmission range switch P position signal In P: about 0 V
In any position other than P: more than 5.0 V
16(2) GRN ATPP (TRANSMISSION RANGE SWITCH P) Detects transmission range switch P position signal In P: about 0 V
In any position other than P: battery voltage
18 PUR APSA (ACCELERATOR PEDAL POSITION (APP) SENSOR A) Detects APP sensor A signal With ignition switch ON (II) and accelerator pedal pressed: about 4.7 V
With ignition switch ON (II) and accelerator pedal released: about 1.0 V
NOTE: Check the label on the PCM to see if it was made by Keihin or Continental. Refer to the GENERAL TROUBLESHOOTING INFORMATION  for more details.
(1) Continental PCM
(2) Keihin PCM


Fig 1: Identifying PCM Inputs And Outputs At PCM Connector A (49P)
G08052430Courtesy of AMERICAN HONDA MOTOR CO., INC.
Terminal number Wire color Terminal name Description Signal
19 LT GRN APSB (ACCELERATOR PEDAL POSITION (APP) SENSOR B) Detects APP sensor B signal With ignition switch ON (II) and accelerator pedal pressed: about 2.3 V
With ignition switch ON (II) and accelerator pedal released: about 0.5 V
20 RED VG+ (MASS AIR FLOW (MAF) SENSOR +SIDE) Detects MAF sensor signal At idle: about 1.1 - 1.6 V (between VG + terminal and VG- terminal)
21 PUR ECT2 (ENGINE COOLANT TEMPERATURE (ECT) SENSOR 2) Detects ECT sensor 2 signal With ignition switch ON (II): about 0.1-4.8 V (depending on engine coolant temperature)
22 LT GRN VSV (EVAPORATIVE EMISSION (EVAP) CANISTER VENT SHUT VALVE) Drives EVAP canister vent shut valve With ignition switch ON (II): battery voltage
23(1) GRN VBUM (VOLTAGE BACK UP) Power source for PCM memory Battery voltage at all times
24 RED VCC3 (SENSOR VOLTAGE) Provides sensor reference voltage With ignition switch ON (II): about 5.0 V
25 ORN VCC4 (SENSOR VOLTAGE) Provides sensor reference voltage With ignition switch ON (II): about 5.0 V
26 WHT SG3 (SENSOR GROUND) Sensor ground Less than 0.2 V at all times
27 GRN SG4 (SENSOR GROUND) Sensor ground Less than 0.2 V at all times
28 PNK STRLD (STARTER SIGNAL LOAD) Detects starter cut relay 2 With ignition switch in START (III): battery voltage
29 BLU ETCSRLY (ELECTRONIC THROTTLE CONTROL SYSTEM (ETCS) CONTROL RELAY) Drives electronic throttle control system (ETCS) control relay With ignition switch ON (II): about 0 V
30 BLU VSSOUT (VEHICLE SPEED SIGNAL OUTPUT) Sends vehicle speed signal Depending on vehicle speed: pulses
31 LT BLU STS (STARTER SWITCH SIGNAL) Detects starter switch signal With ignition switch in START (III): battery voltage
With ignition switch in any position other than START (III): about 0 V
32 BRN SCS (SERVICE CHECK SIGNAL) Detects service check signal With service check signal shorted using the HDS: about 0 V
With service check signal opened: about 5.0 V
36 GRIM SUPP (PADDLE SHIFTER+ (UPSHIFT SWITCH)) Detects paddle shifter- (- (upshift switch) signal With ignition switch ON (II) and paddle shifter+ (upshift switch) pressed: about 0 V
With paddle shifter+ (upshift switch) released: battery voltage
37 BLU SDNP (PADDLE SHIFTER- (DOWNSHIFT SWITCH)) Detects paddle shifter- (downshift switch) signal With ignition switch ON (II) and paddle shifter- (downshift switch) pressed: about 0 V
With paddle shifter- (downshift switch) released: battery voltage
NOTE: Check the label on the PCM to see if it was made by Keihin or Continental. Refer to the GENERAL TROUBLESHOOTING INFORMATION  for more details.
(1) Continental PCM


Fig 1: Identifying PCM Inputs And Outputs At PCM Connector A (49P)
G08052431Courtesy of AMERICAN HONDA MOTOR CO., INC.
Terminal number Wire color Terminal name Description Signal
38 PNK PSPSW (POWER STEERING PRESSURE SWITCH SIGNAL) Detects PSP switch signal At idle with steering wheel straight ahead: about 0 V
At idle with steering wheel at full lock: battery voltage
39 LT GRN FTP (FUEL TANK PRESSURE (FTP) SENSOR) Detects FTP sensor signal With ignition switch ON (II) and fuel fill cap removed: about 2.5 V
40 RED SUBRLY (PGM-FI SUBRELAY) Drives PGM-FI subrelay With ignition switch ON (II): about 0 V
41 BRN LG3 (LOGIC GROUND) Ground circuit for PCM Less than 0.2 V at all times
42 LT BLU FPCD (FUEL PUMP CONTROL MODULE DIAGNOSIS) Detects fuel pump control module diagnosis With ignition switch ON (II): about 5.0 V
At idle: about 10.0 V
43 PNK FPC (FUEL PUMP CONTROL) Detects fuel pump control module signal With ignition switch ON (II): pulses
44-3 GRY WEN (WRITE ENABLE SIGNAL) Detects write enable signal With ignition switch ON (II): about 0 V
46 LT GRN S-NET5V (SERIAL COMMUNICATION FOR IMMOBILIZER) Sends serial communication signal With ignition switch ON (II): pulses With key removed from ignition switch: about 5.0 V
48 WHT F-CAN A H (F-CAN COMMUNICATION SIGNAL A HIGH) Sends and receives communication signal With ignition switch ON (II): pulses
49 RED F-CAN A L (F-CAN COMMUNICATION SIGNAL A LOW) Sends and receives communication signal With ignition switch ON (II): pulses
(1) '10-11 models