2021 Subaru Ascent BaseFACTORY OEM SERVICE PROCEDURE

Body Integrated Unit

G11264375Courtesy of SUBARU OF AMERICA, INC.
Terminal No. Contents Measuring condition Standard
(B280) No. 1 ←→ Chassis ground BAT power supply (control) Always 9 - 16 V
(B280) No. 2 ←→ Chassis ground Turn light output right front Right front turn signal OFF β†’ ON Less than 1 V β†’ 9 - 16 V
(B280) No. 3 ←→ Chassis ground BAT power supply (head Hi right side) (RHB) Always 9 - 16 V
(B280) No. 4 ←→ Chassis ground BAT power supply (illumination) Always 9 - 16 V
(B280) No. 5 ←→ Chassis ground Rear wiper RTN Rear wiper stop position β†’ in operation Less than 1 V β†’ 9 - 16 V
(B280) No. 6 ←→ Chassis ground Front wiper RTN Front wiper stop position β†’ in operation Less than 1 V β†’ 9 - 16 V
(B280) No. 7 ←→ Chassis ground BAT power supply (tail) Always 9 - 16 V
(B280) No. 8 ←→ Chassis ground Turn light output left front Left front turn signal OFF β†’ ON Less than 1 V β†’ 9 - 16 V
(B280) No. 9 ←→ Chassis ground Headlight Hi right side output Headlight Hi OFF β†’ ON Less than 1 V β†’ 9 - 16 V
(B280) No. 10 ←→ Chassis ground Tail light output Tail light OFF β†’ ON Less than 1 V β†’ 9 - 16 V
(B280) No. 11 ←→ Chassis ground Illumination output Illumination OFF β†’ ON Less than 1 V β†’ 9 - 16 V
(B280) No. 12 ←→ Chassis ground Key lock solenoid output (CVT Model without the keyless access with push button start system)
  • Ignition key inserted
  • Select lever, P range β†’ other than P range
 Less than 1 V β†’ 9 - 16 V
(B287) No. 1 ←→ Chassis ground GND Always Less than 1 Ξ©
(B287) No. 2 ←→ Chassis ground Rear wiper relay output Rear wiper OFF β†’ ON 9 - 16 V β†’ Less than 1 V
(B287) No. 3 ←→ Chassis ground BAT power supply (head Hi left side) (LHB) Always 9 - 16 V
(B287) No. 4 ←→ Chassis ground BAT power supply (shift lock/key lock/turn light) Always 9 - 16 V
(B287) No. 5 ←→ Chassis ground DRL right relay output While brake pedal is depressed during engine start, EPB switch ON β†’ OFF, and then the select lever "P" range β†’ other than P range 9 - 16 V β†’ Less than 1 V
(B287) No. 6 ←→ Chassis ground Lighting relay power supply (control) ACC OFF β†’ ON (with keyless access with push button start system), or ignition key not inserted β†’inserted (without keyless access with push button start system) Less than 1 V β†’ 9 - 16 V
(B287) No. 7 ←→ Chassis ground Headlight Hi left side output Headlight Hi OFF β†’ ON Less than 1 V β†’ 9 - 16 V
(B287) No. 8 - - -
(B281) No. 1 ←→ Chassis ground Front fog light relay output Lighting switch 2 ON, then front fog light switch OFF β†’ ON 9 - 16 V β†’ Less than 1 V
(B281) No. 2 ←→ Chassis ground Answer-back buzzer Answer-back buzzer OFF β†’ ON Less than 1 V β†’ 9 - 16 V
(B281) No. 3 ←→ Chassis ground Hood switch Hood closed β†’ open Less than 1 V β†’ 9 - 16 V
(B281) No. 4 ←→ Chassis ground Wiper deicer output Rear window defogger switch OFF β†’ ON (press and hold for three seconds) 9 - 16 V β†’ Less than 1 V
(B281) No. 5 ←→t Chassis ground Rear defogger output Rear window defogger switch OFF β†’ ON 9 - 16 V β†’ Less than 1 V
(B281) No. 6 - - -
(B281) No. 7 ←→ Chassis ground BAT (backup) Always 9 - 16 V
(B281) No. 8 - - -
(B281) No. 9 ←→t Chassis ground Security horn output Security horn, not operating β†’ operating 9 - 16 V β†’ Less than 1 V
(B281) No. 10 - - -
(B281) No. 11 - - -
(B281) No. 12 ←→ Chassis ground Front wiper Hi relay output (control) Front wiper Hi switch OFF β†’ ON (With auto wiper) Less than 1 V β†’ 9 - 16 V
(B281) No. 13 ←→ Chassis ground Front wiper Lo relay output Front wiper Lo switch OFF β†’ ON (With auto wiper) Less than 1 V β†’ 9 - 16 V
(B281) No. 14 ←→ Chassis ground EGI immobilizer communication Always (Without keyless access with push button start system) Serial communication
(B281) No. 15 - - -
(B281) No. 16 ←→ Chassis ground Stop light switch Stop light switch OFF β†’ ON Less than 1 V β†’ 9 - 16 V
(B281) No. 17 Body CAN (H) Except for sleep status (1) Serial communication
(B281) No. 18 - - -
(B281) No. 19 Body CAN (L) Except for sleep status(1) Serial communication
(B281) No. 20 ←→ Chassis ground Lighting Lo relay output (control) Lighting switch 2 OFF β†’ ON 9 - 16 V β†’ Less than 1 V
(i84) No. 1 ←→ Chassis ground
  • Key-in switch (without keyless access with push button start system)
  • ACC switch (with keyless access with push button start system)
  • Ignition key not inserted - inserted (without keyless access with push button start system)
  • ACC switch OFF β†’ ON (with keyless access with push button start system)
 Less than 1 V β†’ 9 - 16 V
(i84) No. 2 ←→ Chassis ground Turn light output left rear Left rear turn signal OFF β†’ ON Less than 1 V β†’ 9 - 16 V
(i84) No. 3 ←→ Chassis ground Shift lock solenoid
  • IG ON
  • Select lever in P range
  • Stop light switch OFF (brake pedal not depressed) β†’ ON (brake pedal depressed)
 Less than 1 V β†’ 9 - 16 V
(i84) No. 4 ←→ Chassis ground GND Always Less than 1 Ξ©
(i84) No. 5 ←→ Chassis ground Turn light output right rear Right rear turn signal OFF β†’ ON Less than 1 V β†’ 9 - 16 V
(i84) No. 6 ←→ Chassis ground Door lock output (driver's seat unlock) When UNLOCK signal is output Less than 1 V β†’ 9 - 16 V
(i84) No. 7 ←→ Chassis ground Electric fuel unlock output When UNLOCK signal is output Less than 1 V β†’ 9 - 16 V
(i84) No. 8 ←→ Chassis ground Luggage light output Rear gate opens β†’ closes with the luggage light DOOR Less than 1 V β†’ 9 - 16 V
(i84) No. 9 ←→ Chassis ground Reading light 2nd output Any one of doors open β†’ close Less than 1 V β†’ 9 - 16 V
(i84) No. 10 - - -
(i171) No. 1 Main system CAN (H) Except for sleep status(1) Serial communication
(i171) No. 2 Main system CAN (L) Except for sleep status(1) Serial communication
(i171) No. 3 ←→ Chassis ground Immobilizer antenna (A) When ignition key inserted (Without keyless access with push button start system and without immobilizer control module) Pulse generation
(i171) No. 4 ←→ Chassis ground Immobilizer antenna (B) When ignition key inserted (Without keyless access with push button start system and without immobilizer control module) Pulse generation
(i171) No. 5 - - -
(i171) No. 6 ←→ Chassis ground Rear gate opener button Rear gate opener button OFF β†’ ON 9 - 16 V β†’ Less than 1 V
(i171) No. 7 ←→ (i171) No. 8 Sensitivity adjustment SIG Always (With auto wiper) 0 - 6 kΞ©
(i171) No. 8 ←→ Chassis ground Sensitivity adjustment GND - -
(i171) No. 9 ←→ Chassis ground Key ring illumination output IG OFF β†’ ON with driver's door open (With auto wiper) Less than 1 V β†’ 9 - 16 V
(i171) No. 10 ←→ Chassis ground Map light output Door opens - closes with the map light DOOR Less than 1 V β†’ 9 - 16 V
(i171) No. 11 ←→ Chassis ground Room light power supply relay output Back-up fuse not inserted β†’ inserted, and then one-touch all lighting switch OFF β†’ ON 9 - 16 V β†’ Less than 1 V
(i171) No. 12 ←→ Chassis ground Manual unlock switch Door unlock switch OFF β†’ ON 9 - 16 V β†’ Less than 1 V
(i171) No. 13 ←→ Chassis ground Door switch (passenger's seat) Passenger's door closed β†’ open 9 - 16 V β†’ Less than 1 V
(i171) No. 14 ←→ Chassis ground Door switch (rear seat LH) Rear seat LH door closed β†’ open 9 - 16 V β†’ Less than 1 V
(i171) No. 15 ←→ Chassis ground Door switch (rear gate) Rear gate close β†’ open 9 - 16 V β†’ Less than 1 V
(i171) No. 16 ←→ Chassis ground Reading light 3rd output Any one of doors open β†’ close Less than 1 V β†’ 9 - 16 V
(i171) No. 17 - - -
(i171) No. 18 ←→ Chassis ground Lighting Lo relay output (redundant circuit) Lighting switch 2 OFF β†’ ON 9 - 16 V β†’ Less than 1 V
(i171) No. 19 ←→ Chassis ground Lighting switch 2 (redundant circuit) Lighting switch 2 OFF β†’ ON 9 - 16 V β†’ Less than 1 V
(i171) No. 20 ←→ Chassis ground Security indicator light output When security light is illuminating Pulse generation
(i171) No. 21 ←→ Chassis ground Front wiper Hi switch (redundant circuit) Front wiper Hi switch OFF β†’ ON (With auto wiper) Less than 1 V β†’ 9 - 16 V
(i171) No. 22 ←→ Chassis ground Front wiper Hi relay output (redundant circuit) Front wiper Hi switch OFF β†’ ON (With auto wiper) Less than 1 V β†’ 9 - 16 V
(i171) No. 23 ←→ Chassis ground Lighting relay power supply (redundant circuit) ACC OFF β†’ ON (with keyless access with push button start system), or ignition key not inserted β†’ inserted (without keyless access with push button start system) Less than 1 V β†’ 9 - 16 V
(i171) No. 24 Diagnosis related CAN (H) Except for sleep status(1) Serial communication
(i171) No. 25 Diagnosis related CAN (L) Except for sleep status(1) Serial communication
(i171) No. 26 ←→ Chassis ground Dimmer Hi switch Dimmer switch Hi beam OFF β†’ON 9 - 16 V β†’ Less than 1 V
(i171) No. 27 ←→ Chassis ground Door switch (rear seat RH) Rear seat RH door closed β†’ open 9 - 16 V β†’ Less than 1 V
(i171) No. 28 ←→ (i171) No. 8 Illumination sensor signal When lighting switch is at AUTO 0 - 4.5 V
(i171) No. 29 - - -
(i171) No. 30 - - -
(i171) No. 31 - - -
(i171) No. 32 ←→ Chassis ground Manual lock switch Door lock switch OFF - ON 9 - 16 V β†’ Less than 1 V
(i171) No. 33 ←→ Chassis ground Turn signal switch right Turn signal switch right OFF β†’ ON 9 - 16 V β†’ Less than 1 V
(i171) No. 34 ←→ (i171) No. 8 Illumination sensor power supply output Ignition switch OFF β†’ ON Less than 1 V β†’ 5 V
(i171) No. 35 ←→ Chassis ground Lighting I switch Lighting switch 1 OFF β†’ ON 9 - 16 V β†’ Less than 1 V
(i171) No. 36 ←→ Chassis ground Dimmer Pass switch Dimmer switch Pass OFF β†’ ON 9 - 16 V β†’ Less than 1 V
(i171) No. 37 ←→ Chassis ground Turn hazard switch Turn hazard switch OFF β†’ ON 9 - 16 V β†’ Less than 1 V
(i171) No. 38 ←→ Chassis ground Turn signal switch left Turn signal switch left OFF β†’ ON 9 - 16 V β†’ Less than 1 V
(i171) No. 39 ←→ Chassis ground Door switch (driver's seat) Driver's door closed β†’ open 9 - 16 V β†’ Less than 1 V
(i171) No. 40 ←→ Chassis ground P range switch Select lever, other than P range β†’ P range (CVT model) 9 - 16 V β†’ Less than 1 V
(i81) No. 1 ←→ Chassis ground Front wiper Lo switch Front wiper Lo switch OFF β†’ ON (With auto wiper) Less than 1 V β†’ 9 - 16 V
(i81) No. 2 LIN communication 2 Except for sleep status(1) Serial communication
(i81) No. 3 ←→ Chassis ground Rear wiper switch (INT) Rear wiper switch INT OFF β†’ ON 9 - 16 V β†’ Less than 1 V
(i81) No. 4 ←→ Chassis ground One-touch all lighting switch One-touch all lighting switch OFF β†’ ON 9 - 16 V β†’ Less than 1 V
(i81) No. 5 - - -
(i81) No. 6 ←→ Chassis ground Door lock status switch passenger's seat Passenger's door lock β†’ unlock (With keyless access with push button start system) 9 - 16 V β†’ Less than 1 V
(i81) No. 7 - - -
(i81) No. 8 ←→ Chassis ground Ambient light output Door closed β†’ open 9 - 16 V β†’ Less than 1 V
(i81) No. 9 - - -
(i81) No. 10 ←→ Chassis ground Rear washer switch Rear washer switch OFF β†’ ON 9 - 16 V β†’ Less than 1 V
(i81) No. 11 - - -
(i81) No. 12 ←→ Chassis ground Front washer switch Front washer switch OFF β†’ ON 9 - 16 V β†’ Less than 1 V
(i81) No. 13 - - -
(i81) No. 14 - - -
(i81) No. 15 - - -
(i81) No. 16 - - -
(i81) No. 17 ←→ Chassis ground Front wiper Hi switch (control) Front wiper Hi switch OFF β†’ ON (With auto wiper) Less than 1 V β†’ 9 - 16 V
(i81) No. 18 LIN communication 1 Except for sleep status(1) Serial communication
(i81) No. 19 ←→ Chassis ground Rear wiper switch (ON) Rear wiper switch OFF β†’ ON 9 - 16 V β†’ Less than 1 V
(i81) No. 20 ←→ Chassis ground Lighting switch AUTO Lighting switch AUTO OFF β†’ ON 9 - 16 V β†’ Less than 1 V
(i81) No. 21 ←→ Chassis ground Front wiper switch AUTO Front wiper switch AUTO OFF β†’ ON (With auto wiper) 9 - 16 V β†’ Less than 1 V
(i81) No. 22 ←→ Chassis ground Door lock status switch driver's seat Driver's door lock β†’ unlock (With keyless access with push button start system) 9 - 16 V β†’ Less than 1 V
(i81) No. 23 - - -
(i81) No. 24 ←→ Chassis ground DRL left relay output While brake pedal is depressed during engine start, EPB switch ON β†’ OFF, and then the select lever "P" range β†’ other than P range -
(i81) No. 25 - - -
(i81) No. 26 ←→ Chassis ground Front fog light switch Front fog light switch OFF β†’ ON 9 - 16 V β†’ Less than 1 V
(i81) No. 27 - - -
(i81) No. 28 ←→ Chassis ground Lighting switch 2 (control) Lighting switch 2 OFF β†’ ON 9 - 16 V β†’ Less than 1 V
(i81) No. 29 - - -
(i81) No. 30 - - -
(i81) No. 31 ←→ Chassis ground Collision detection signal IG ON Pulse output
(i81) No. 32 - - -
(1) For CAN or LIN sleep state, hold on for approx. one minute with ignition switch OFF and all the doors and trunk/rear gate closed.
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