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Home >> Mazda >> 2011 >> 3 Mazdaspeed, 2.3 4 >> Repair and Diagnosis (Single Page) >> Body & Frame >> Door Locks >> Symptom Troubleshooting [Keyless Entry System] >> No. 2 All Keyless Entry System Functions Inoperative [Keyless Entry System]

No. 2 All Keyless Entry System Functions Inoperative [Keyless Entry System]

All keyless entry system functions inoperative 
DESCRIPTION 
  • Malfunction in BCM power supply circuit, door latch switch circuit, BCM ground circuit, or keyless receiver.
POSSIBLE CAUSE 
  • Malfunction in IG1 or power supply signal circuit of BCM
    • BCM power supply fuse malfunction
    • Malfunction in wiring harness between BCM power supply fuses and BCM
  • Malfunction in door open/closed signal circuit of BCM
    • Door latch switch system malfunction
    • BCM malfunction
    • Malfunction in wiring harness between BCM and door latch switch
  • Malfunction in BCM GND signal circuit
    • Malfunction in wiring harness between BCM and ground
  • Malfunction in keyless receiver
    • Keyless receiver malfunction
    • Malfunction in wiring harness between keyless receiver and BCM
G07875065
DIAGNOSTIC PROCEDURE

STEP INSPECTION ACTION
1 INSPECT BCM POWER SUPPLY FUSES 
  • Are the BCM power supply fuses normal?
Yes Go to the next step.
No Install an appropriate amperage fuse.
2 INSPECT DOOR LATCH SWITCH INSTALLATION 
  • Are the door latch switches installed securely?
Yes Go to the next step.
No Install the door latch switches securely, then go back to Step 5 of keyless entry system preliminary inspection.
*3 INSPECT IF MALFUNCTION IS IN WIRING HARNESS (NO CONTINUITY BETWEEN FUSE BLOCK AND BCM) OR ELSEWHERE 
  • Switch the ignition to ON.
  • Measure the voltage at the following BCM terminals:
    • IG1 signal (terminal 4T)
    • Power supply signal (terminal 3J, 5B, 4S)
  • Is the voltage B+  ?
Yes Go to the next step.
No Repair the wiring harness between the fuse block and BCM, then go to Step 13.
*4 INSPECT IF MALFUNCTION IS IN WIRING HARNESS (SHORT TO POWER SUPPLY BETWEEN FUSE BLOCK AND BCM, OR BETWEEN BCM AND GROUND) OR ELSEWHERE 
  • Switch the ignition to off.
  • Disconnect the BCM connector.
  • Measure the voltage at the following BCM terminal (wiring harness-side):
    • IG1 signal (terminal 4T)
  • Is the voltage B+  ?
Yes Repair the malfunctioning wiring harness, then go to Step 13.
No Go to the next step.
*5 INSPECT IF MALFUNCTION IS IN WIRING HARNESS (NO CONTINUITY BETWEEN BCM AND GROUND) OR ELSEWHERE 
  • Is there continuity between BCM terminal 2N, 4B and ground?
Yes Go to the next step.
No Repair the wiring harness between the BCM and ground, then go to Step 13.
6 INSPECT DOOR SWITCH SIGNAL 
  • Monitor following BCM (door switch) PID using the M-MDS.
    • TR/LG_SW (Trunk lid/liftgate latch switch)
    • DRSW_P (Passenger's door latch switch)
    • DRSW_D (Driver's door latch switch)
    • DRSW_LR (Left Rear door latch switch)
    • DRSW_RR (Right Rear door latch switch)
  • Are monitored PID values normal?
Yes Go to the next step.
No
7 INSPECT BCM OR WIRING HARNESS (BETWEEN BCM AND DOOR LATCH SWITCHES FOR CONTINUITY) 
  • Open and close all doors.
  • Verify continuity between BCM terminals 6G, 6H, 6K, 6E and ground.
  • Are there continuities followings?
    • Open: Not continuity
    • Close: Continuity
Yes Replace the BCM and reprogram the transmitter ID code, then go to the next step.
No Repair the wiring harness between the BCM and door latch switches, then go to the next step.
8 INSPECT POWER SUPPLY FUSE 
  • Is the keyless receiver power supply fuse normal?
Yes Go to the next step.
No Inspect and repair short to GND in wiring harness at keyless receiver power supply circuit install an appropriate amperage fuse, then go to step 13.
9 INSPECT IF MALFUNCTION IS IN WIRING HARNESS (NO CONTINUITY BETWEEN FUSE BLOCK AND KEYLESS RECEIVER) OR ELSEWHERE 
  • Measure the voltage at the following keyless receiver terminal:
    • B+ signal (terminal A)
  • Is the voltage B+  ?
Yes Go to the next step.
No Repair the wiring harness between the fuse block and keyless receiver, then go to Step 13.
10 INSPECT IF MALFUNCTION IS IN WIRING HARNESS (NO CONTINUITY BETWEEN KEYLESS RECEIVER AND GROUND) OR ELSEWHERE 
  • Is there continuity between keyless receiver terminal E and ground?
Yes Go to the next step.
No Repair the wiring harness between the keyless receiver and ground, then go to Step 13.
11 INSPECT IF MALFUNCTION IS IN WIRING HARNESS (NO CONTINUITY BETWEEN KEYLESS RECEIVER AND BCM) OR ELSEWHERE 
  • Disconnect the keyless receiver connector and BCM connector.
  • Is there continuity between the following terminals?
    • 4K (BCM connector)-D (keyless receiver connector)
Yes Go to the next step.
No Repair the wiring harness between the keyless receiver and BCM, then go to Step 13.
12
  • Measure the signal wave pattern for keyless receiver terminal D (6-pin) using an oscilloscope when the transmitter is operated with the key not inserted into the ignition key cylinder.
  • Does the wave pattern change when the transmitter is operated?
    NOTE:
    • Perform the oscilloscope setting using 0.5V/DIV (Y), 100ms/DIV (X), DC range.
Yes Replace the BCM, then go to the next step.
(See BODY CONTROL MODULE (BCM) REMOVAL/INSTALLATION ).
No Replace the keyless receiver, then go to the next step.
(See KEYLESS RECEIVER REMOVAL/INSTALLATION ).
13 REINSPECT MALFUNCTION SYMPTOM AFTER REPAIR 
  • Does the keyless entry system operate properly?
Yes Troubleshooting completed.
Explain repairs to the customer.
No Reinspect the malfunction symptoms, then repeat from Step 1 if the malfunction recurs.