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VTM-4 Control Unit Inputs and Outputs

The VTM-4 control unit terminal voltage and measuring conditions for the 4WD control system are shown.

Fig 1: Identifying VTM-4 Control Unit Inputs And Outputs
G03640818Courtesy of AMERICAN HONDA MOTOR CO., INC.
TERMINAL CONDITION SPECIFICATION

Terminal number Wire color Terminal sign (Terminal name) Description Measurement
Conditions Voltage
A1 YEL IG1 (Ignition 1) Power supply for activating the system Ignition switch ON (II) Battery Voltage
A3 GRY/RED RRP (Rear right pulse) Detect right-rear wheel sensor signal Turn wheel at 1 rotation/second 2-3 V Turn real slow
5V Faster pulse
0-5 V
A4 ORN/GRN FSR (Fail-safe relay) Drives VTM-4 relay Ignition switch ON (II) Battery Voltage
Engine running Below 1 V
A5 GRY/YEL RLP (Rear left pulse) Detects left-rear wheel sensor signal Turn wheel at 1 rotation/second 2-3 V Turn real slow
5V Faster pulse
0-5 V
A6 GRN/RED PARBRK (Parking brake) Detects parking brake signal Parking brake on Below 2 V
Parking brake off Battery Voltage
A7 LT GRN FRP (Front right pulse) Detects right-front wheel sensor signal Turn wheel at 1 rotation/second 2-3 V Turn real slow
5V Faster pulse
0-5 V
A8 BRN/WHT LOCKSW (Lock button) Detects VTM-4 LOCK button signal Ignition switch ON (II) Below 1 V
VTM-4 lock mode Battery Voltage
A9 WHT/RED FLP (Front left pulse) Detects left-front wheel sensor signal Turn wheel at 1 rotation/second 2-3 V Turn real slow
5V Faster pulse
0-5 V


The VTM-4 control unit terminal voltage and measuring conditions for the 4WD control system are shown.

Fig 1: Identifying VTM-4 Control Unit Inputs And Outputs
G03640819Courtesy of AMERICAN HONDA MOTOR CO., INC.
TERMINAL CONDITION SPECIFICATION

Terminal number Wire color Terminal sign (Terminal name) Description Measurement
Conditions Voltage
A10 BLK LG1 (Logic ground) Ground   Below 1 V
A11 WHT CANH (CAN communication signal high) CAN communication signal Ignition switch ON (II) 2.0-4.5 V
A12 GRN/BLU NEP (Engine revolution) Detects engine revolution signal Ignition switch ON (II) Above 8 V
Engine running at 1,000 rpm 5-8 V
A13 BLK TCL (Temperature coil low) Detects differential oil temperature sensor signal Check at normal temperature with the ignition switch ON (II) 1-3.6 V
A14 RED/WHT WARN 1 (Warning 1) Drives VTM-4 indicator VTM-4 indicator on Below 4 V
VTM-4 indicator off Battery Voltage
A15 WHT TCH (Temperature coil high) Power supply for differential oil temperature sensor Check at normal temperature with the ignition switch ON (II) 4-5 V
A16 YEL/BLK LOCKL (Lock lamp) Drives VTM-4 LOCK indicator VTM-4 LOCK indicator on Below 4 V
VTM-4 LOCK indicator off Battery Voltage
A18 LT BLU LET (Line end tester) Communication signal to HDS Ignition switch ON (II) (Not connected to HDS) About 5 V
A20 BRN SCS (Service check signal) Detects service check connector signal SCS circuit shorted Below 2 V
SCS circuit opened About 5 V
A22 RED CANL (CAN communication signal low) CAN communication signal Ignition switch ON (II) 0.5-3.0 V
B1 BLK/RED LCOH (Left coil high) Drives left clutch electromagnetic coil (positive) Ignition switch ON (II) Below 1 V
Engine running Below 1 V
VTM-4 lock mode Above 3 V
B2 BLK/WHT LCOL (Left coil low) Drives left clutch electromagnetic coil (negative) Ignition switch ON (II) Below 1 V
Engine running Below 1 V
VTM-4 lock mode Below 1 V
B3 BRN RCOH (Right coil high) Drives right clutch electromagnetic coil (positive) Ignition switch ON (II) Below 1 V
Engine running Below 1 V
VTM-4 lock mode Above 3 V
B4 GRN RCOL (Right coil low) Drives right clutch electromagnetic coil (negative) Ignition switch ON (II) Below 1 V
Engine running Below 1 V
VTM-4 lock mode Below 1 V
B5 BLK PG (Power ground) Ground   Below 0.5 V
B7 RED/BLU PWR (Power) Power supply for VTM-4 control unit 10 seconds after ignition switch ON (II) Below 3 V
Engine running Battery Voltage
VTM-4 lock mode Above 8 V
B11 RED/WHT WARN 2 (Warning 2) Drives VTM-4 indicator VTM-4 indicator on Below 4 V
VTM-4 indicator off Battery Voltage
B12 BLK LG2 (Logic ground) Ground   Below 1 V