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Home/Mazda/CX-7/Mazda CX-7 I рестайлинг (2009-2012)/Repair manual/Communication Devices/Control System (Body Control Module): Diagnosis
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Control System (Body Control Module): Diagnosis Mazda CX-7 I рестайлинг

Communication Devices 4 illustrations ~338 words

BODY CONTROL MODULE (BCM) INSPECTION

  1. Disconnect the negative battery cable.
  2. Remove the following parts: Front scuff plate, (driver-side) (See «FRONT SCUFF PLATE REMOVAL/INSTALLATION»(ref-375422-S33927733892010102800000) .) Front side trim, (driver-side) (See «FRONT SIDE TRIM REMOVAL/INSTALLATION»(ref-375422-S05380344012010102800000) .) Console panel. (See «CONSOLE PANEL REMOVAL/INSTALLATION»(ref-375422-S16179305552010102800000) .) Console (See «CONSOLE REMOVAL/INSTALLATION»(ref-375422-S05218780952010102800000) .)
  3. Set the hood release lever out of the way. (See «HOOD LATCH AND RELEASE LEVER REMOVAL/INSTALLATION»(ref-375401-S08980162612010102800000) .)
  4. Remove the lower panel. (See «LOWER PANEL REMOVAL/INSTALLATION»(ref-375422-S28238229142010102800000) .)
  5. Remove the BCM with the connector connected. (See «BODY CONTROL MODULE (BCM) REMOVAL/INSTALLATION»(ref-375368-S24092543262010102800000) .)
  6. Connect the negative battery cable.
  7. Measure the voltage at each terminal is as indicated in the Terminal Voltage Tables. If the voltage is not as specified in the Terminal Voltage Table, inspect the parts under "Inspection item (s)". If the system does not work properly even though the parts or related wiring harnesses do not have any malfunction, replace the BCM.

Scheme 87

Scheme 87: Terminal Voltage Table (Reference)
Scheme 87: Terminal Voltage Table (Reference)
TerminalSignalConnected toMeasurement conditionVoltage (V)Inspection item (s)
1AParking brake switch signalParking brake switchIgnition switch at ONParking brake switch on (Parking brake applied)1.0 or lessParking brake switch Related wiring harnesses
Parking brake switch off (Parking brake not applied)B+
1B (1)Hood latch switch signalHood latch switchHood openWave pattern (See PATTERN 1 .)Hood latch switch Related wiring harnesses
Hood closed1.0 or less
1CBrake fluid level signalBrake fluid level sensorIgnition switch at ONBrake fluid level below MIN.B+Brake fluid level sensor Related wiring harnesses
Brake fluid level above MIN.1.0 or less
1DCAN_LCAN system related moduleBecause this terminal is for communication, good/no good judgment by terminal voltage is not possible.
1EOil pressure switch signalOil pressure switchDuring engine startB+Oil pressure switch Related wiring harnesses
While engine stopped1.0 or less
1FCAN_HCAN system related moduleBecause this terminal is for communication, good/no good judgment by terminal voltage is not possible.
1GHazard power supplyHAZARD 10 A fuseUnder any conditionB+Related wiring harnesses
1H
1IPower door lock power supplyD.LOCK 20 A fuseUnder any conditionB+Related wiring harnesses
1J
1KFront turn light (RH) controlFront turn light (RH)Turn switch (RH) onFront turn light (RH) flashesAlternates between 1.0 or less and B+Front turn light (RH) Related wiring harnesses
Hazard warning switch on
Other1.0 or less
1LHorn controlHorn relayHorn sounded1.0 or lessHorn relay Related wiring harnesses
Horn not soundedB+
1MFront turn light (LH) controlFront turn light (LH)Turn switch (LH) onFront turn light (LH) flashesAlternates between 1.0 or less and B+Front turn light (LH) Related wiring harnesses
Hazard warning switch on
Other1.0 or less
1NRear washer motor controlRear washer motorIgnition switch at ONRear washer switch on1.0 or lessRear washer motor Related wiring harnesses
Rear washer switch offB+
1PRear washer motor power supplyRear washer motorSwitch the ignition to ONB+Rear washer motor Related wiring harnesses
Switch the ignition to Off1.0 or less
3AIgnition key illumination power supplyIgnition key illumination (without advanced keyless entry and start system) Steering lock unit (with advanced keyless entry and start system)Under any conditionB+Related wiring harnesses
3BKey reminder switch power supplyKey reminder switchUnder any conditionB+Related wiring harnesses
3CIgnition key illumination controlIgnition key illumination (without advanced keyless entry and start system) Steering lock unit (with advanced keyless entry and start system)Ignition switch off and driver-side door opened.1.0 or lessIgnition key illumination bulb Related wiring harnesses
15 s or more after all doors closed.B+
3DHorn switch signalHorn switchHorn switch offB+Horn switch Related wiring harnesses
Horn switch on1.0 or less
3ESerial communicationInstrument cluster Keyless control module (with advanced keyless entry and start system) Keyless receiver (without advanced keyless entry and start system)Because this terminal is for communication, good/no good judgment by terminal voltage is not possible.
3FKey reminder switch signalSteering lock unit (with advanced keyless entry and start system) Key reminder switch (with keyless entry system)Key insertedB+Steering lock unit (with advanced keyless entry and start system) Key reminder switch (with keyless entry system) Related wiring harnesses
Key removed1.0 or less
3GSteering angle sensor GNDSteering angle sensorUnder any condition1.0 or lessRelated wiring harnesses
3H
31Steering angle sensor signal (Z)Steering angle sensorSteering wheel is in center position0.25-0.75Steering angle sensor Related wiring harnesses
Steering wheel is not in center position4.00-4.75
3JA/C LIN communicationClimate control unitBecause this terminal is for communication, good/no good judgment by terminal voltage is not possible.
3KSteering angle sensor signal (C)Steering angle sensorTurn the steering wheel to the left and right.Alternates between 4.00-4.75 and 0.25-0.75Steering angle sensor Related wiring harnesses
3LA/C on request signalClimate control unit (manual air conditioner)Ignition switch at ONA/C on (Fan switch on)1.0 or lessClimate control unit (manual air conditioner) Related wiring harnesses
A/C offWave pattern (See PATTERN 1 .)
3MSteering angle sensor signal (B)Steering angle sensorTurn the steering wheel to the left and right.Alternates between 4.00-A75 and 0.25-0.75Steering angle sensor Related wiring harnesses
3N
30Steering angle sensor signal (A)Steering angle sensorTurn the steering wheel to the left and right.Alternates between 4.00-4.75 and 0.25-0.75Steering angle sensor Related wiring harnesses
3PTurn switch input (RH)Turn switchIgnition switch at ONTurn switch at right position1.0 or lessTurn switch Related wiring harnesses
OtherB+
3QSteering angle sensor power supplySteering angle sensorSpecified time elapsed since key removal and all doors closedApprox. 2.5Steering angle sensor Related wiring harnesses
Other5
3RTurn switch input (LH)Turn switchIgnition switch at ONTurn switch at left position1.0 or lessTurn switch Related wiring harnesses
OtherB+
3SBCM GNDBody groundUnder any condition1.0 or lessRelated wiring harnesses
3THazard warning switch signalHazard warning switchHazard warning switch on1.0 or lessHazard warning switch Related wiring harnesses
Hazard warning switch offWave pattern (See PATTERN 3 .)
3UCAN_HCAN system related moduleBecause this terminal is for communication, good/no good judgment by terminal voltage is not possible.
3VRear wiper switch signal (on)Windshield wiper and washer switchIgnition switch at ONRear wiper switch at ON position1.0 or lessWiper and washer switch Related wiring harnesses
Other9.35
3WCAN_LCAN system related moduleBecause this terminal is for communication, good/no good judgment by terminal voltage is not possible.
3XRear wiper switch signal (INT)Windshield wiper and washer switchIgnition switch at ONRear wiper switch at INT position1.0 or lessWiper and washer switch Related wiring harnesses
OtherB+
4AHeated outer mirror power supplyM.DEF 7.5 A fuseIgnition switch at ONRear window defroster switch at ON (Rear window defroster relay on)B+Rear window defroster relay Related wiring harnesses
Rear window defroster switch at OFF (Rear window defroster relay off)1.0 or less
4BPower supplyROOM 15 A fuseUnder any conditionB+Related wiring harnesses
4C
4DRear wiper and washer power supplyR.WIPER 10 A fuseIgnition switch at ONB+Ignition switch Rear wiper motor Related wiring harnesses
Ignition switch off1.0 or less
4E
4FRear washer switch signalWindshield wiper and washer switchIgnition switch at ONRear washer switch on1.0 or lessWindshield wiper and washer switch Related wiring harnesses
Rear washer switch offB+
4GBCM GNDBody groundUnder any condition1.0 or lessRelated wiring harnesses
4H
41Power supplyMETER 15A fuseIgnition switch at ONB+Ignition switch Rear wiper motor Related wiring harnesses
Ignition switch off1.0 or less
5A
5BDriver-side door key cylinder switch signalDriver-side door key cylinder switchAt the moment key cylinder is unlocked1.0 or lessDriver-side door key cylinder switch Related wiring harnesses
At the moment key cylinder is locked2.5
Other5
5CCAN_HCAN system related moduleBecause this terminal is for communication, good/no good judgment by terminal voltage is not possible.
5D (1)Lock/unlock input (rear door lock-link switch (LH))Rear door lock-link switch (LH)Rear door (LH) lockedWave pattern (See PATTERN 1 .)Rear door lock-link switch (LH) Related wiring harnesses
Rear door (LH) unlocked1.0 or less
5E (1)Lock/unlock input (rear door lock-link switch (RH))Rear door lock-link switch (RH)Rear door (RH) lockedWave pattern (See PATTERN 1 .)Rear door lock-link switch (RH) Related wiring harnesses
Rear door (RH) unlocked1.0 or less
5FCAN_LCAN system related moduleBecause this terminal is for communication, good/no good judgment by terminal voltage is not possible.
5GLock input (Driver-side door lock-link switch)Driver-side door lock-link switch (without advanced keyless entry and start system)Driver-side door locked1.0 or lessDriver-side door lock-link switch Related wiring harnesses
Driver-side door unlockedWave pattern (See PATTERN 1 .)
Driver-side door lock-link switch Keyless control module (with advanced keyless entry and start system)Driver-side door locked1.0 or lessDriver-side door lock-link switch Related wiring harnesses
Driver-side door unlockedWave pattern (See PATTERN 2 .)
5H (1)Lock/unlock input (passenger-side door lock-link switch)Passenger-side door lock-link switchPassenger-side door locked1.0 or lessPassenger-side door lock-link switch Related wiring harnesses
Passenger-side door unlockedWave pattern (See PATTERN 1 .)
51CAN_HCAN system related moduleBecause this terminal is for communication, good/no good judgment by terminal voltage is not possible.
5JUnlock input (Driver-side door lock-link switch)Driver-side door lock-link switchDriver-side door lockedWave pattern (See PATTERN 1 .)Driver-side door lock-link switch Related wiring harnesses
Driver-side door unlocked1.0 or less
5KLock/unlock signalDoor lock switch (driver-side)Door lock switch (driver-side) is pressed to lock.2.5Door lock switch (driver-side) Related wiring harnesses
Door lock switch (driver-side) is pressed to unlock.1.0 or less
Other5
5LCAN_LCAN system related moduleBecause this terminal is for communication, good/no good judgment by terminal voltage is not possible.
5M
5NLock/unlock signalDoor lock switch (passenger-side)Door lock switch (passenger-side) is pressed to lock.2.5Door lock switch (passenger-side) Related wiring harnesses
Door lock switch (passenger-side) is pressed to unlock.1.0 or less
Other5
50Rear turn light (RH) controlRear turn light (RH) Front side turn light (with front side turn light) Trailer tow connector (with trailer tow)Turn switch (RH) onRear turn light (RH) flashesAlternates between 1.0 or less and B+Rear turn light (RH) Related wiring harnesses
Hazard warning switch on
Other1.0 or less
5P
5Q
5RRear turn light (LH) controlRear turn light (LH) Front side turn light (with front side turn light) Trailer tow connector (with trailer tow)Turn switch (LH) onRear turn light (LH) flashesAlternates between 1.0 or less and B+Rear turn light (LH) Related wiring harnesses
Hazard warning switch on
Other1.0 or less
5SInterior light power supplyMap light Interior light Cargo compartment light Auto dimming mirror Vanity mirror illumination Position memory control moduleUnder any conditionB+Map light Interior light Related wiring harnesses
5TLiftgate latch switch signalLiftgate latch switch Cargo compartment lightLiftgate is open. (Liftgate latch switch off)B+Liftgate latch switch Related wiring harnesses
Liftgate is closed. (Liftgate latch switch on)1.0 or less
5U
5VFront door switch (passenger-side) signalFront door switch (passenger-side)Front door (passenger-side) open (Front door switch (passenger-side) on)1.0 or lessFront door switch (passenger-side) Related wiring harnesses
Front door (passenger-side) closed (Front door switch (passenger-side) off)Wave pattern (See PATTERN 3 .)
5WSerial communicationPower window main switch Sunroof motor Position memory control moduleBecause this terminal is for communication, good/no good judgment by terminal voltage is not possible.
5X
5YRear door switch (LH) signalRear door switch (LH)Rear door (LH) open (Rear door switch on)1.0 or lessRear door switches Related wiring harnesses
Rear door (LH) closed (Rear door switch off)Wave pattern (See PATTERN 3 .)
5ZRear door switch (RH) signalRear door switch (RH)Rear door (RH)open (Rear door switch on)1.0 or lessRear door switches Related wiring harnesses
Rear door (RH) closed (Rear door switch off)Wave pattern (See PATTERN 3 .)
5AA
5ABFront door switch (driver-side) signalFront door switch (driver-side)Front door (driver-side) open (Front door switch (driver-side) on)1.0 or lessFront door switch (driver-side) Position memory control module (with memory power seat) Related wiring harnesses
Front door (driver-side) closed (Front door switch (driver-side) off)Wave pattern (See PATTERN 3 .)
Front door switch (driver-side) Position memory control module (with memory power seat)Front door (driver-side) open (Front door switch (driver-side) on)1.0 or less
Front door (driver-side) closed (Front door switch (driver-side) off)Wave pattern (See PATTERN 4 .)
5ACHeated outer mirror controlHeated outer mirror (driver-side)Rear window defroster relay onB+Rear window defroster relay Heated outer mirror (driver-side) Related wiring harnesses
Rear window defroster relay off1.0 or less
5ADHeated outer mirror controlHeated outer mirror (passenger-side)Rear window defroster relay onB+Rear window defroster relay Heated outer mirror (passenger-side) Related wiring harnesses
Rear window defroster relay off1.0 or less
6ARear wiper controlRear wiper motorRear wiper moving1.0 or lessRear wiper motor Related wiring harnesses
Rear wiper stoppedB+
6BInterior light controlMap light Interior lightWithin 5 min after any door is opened.1.0 or lessMap light Interior light Related wiring harnesses
5 min or more after any door is opened.B+
All doors closedB+
6CDriver-side door unlock controlDriver-side door lock actuatorDriver-side door lock actuator unlocking1.0 or less -->B+-->1.0 or lessDriver-side door lock actuator Related wiring harnesses
Other1.0 or less
6D
6EDoor lock controlDoor lock actuatorsDoor lock actuators unlocking1.0 or less -->B+-->1.0 or lessDoor lock actuators Related wiring harnesses
Other1.0 or less
6FDoor unlock controlDoor lock actuatorsDoor lock actuators locking1.0 or less --> B+ --> 1.0 or lessDoor lock actuators Related wiring harnesses
Other1.0 or less
(1) With theft-deterrent system
(1)With theft-deterrent system

INSPECTION CHART

Scheme 88

Scheme 88: Pattern 1
Scheme 88: Pattern 1
  1. Terminal: Hood latch switch signal: 1B (+) <==> body ground (-) A/C on request signal: 3L (+) <==> body ground (-) Lock/unlock input (rear door lock-link switch (LH)): 5D (+) <==> body ground (-) Lock/unlock input (rear door lock-link switch (RH)): 5E (+) <==> body ground (-) Lock input (Driver-side door lock-link switch): 5G (+) <==> body ground (-) Lock/unlock input (passenger-side door lock-link switch): 5H (+) <==> body ground (-) Unlock input (Driver-side door lock-link switch): 5J (+) <==> body ground (-)
  2. Oscilloscope setting: 2 V/DIV (Y), 1 ms/DIV (X), DC range

Scheme 89

Scheme 89: Pattern 2
Scheme 89: Pattern 2
  1. Terminal: 5G (+) <==> body ground (-)
  2. Oscilloscope setting: 2 V/DIV (Y), 1 ms/DIV (X), DC range

Scheme 90

Scheme 90: Pattern 3
Scheme 90: Pattern 3
  1. Terminal: Hazard warning switch signal: 3T (+) <==> body ground (-) Front door switch (passenger-side) signal: 5V (+) <==> body ground (-) Rear door switch (LH) signal: 5Y (+) <==> body ground (-) Rear door switch (RH) signal: 5Z (+) <==> body ground (-) Front door switch (driver-side) signal: 5AB (+) <==> body ground (-)
  2. Oscilloscope setting: 2 V/DIV (Y), 1 ms/DIV (X), DC range

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