Pinpoint Test J: DTC B2633 Driver - Front Microphone Circuit Failure

WARNING: This page is about a different car, the 2005 Lincoln LS. However, it is still accessible from the selected car via links, so may be relevant.

J1 CHECK VOICE SIGNAL FROM THE MICROPHONE
- Key in OFF position.
- Disconnect: Navigation System Module C4209.
- Key in ON position.
- Measure the voltage between the navigation system module C4209-7, circuit 8-MC8 (WH/RD), harness side and between the navigation system module C4209-19, 9-MC8 (BN/RD), harness side while speaking loudly into the rear view mirror microphone.
  
  Fig 1: Checking Voice Signal From Microphone
  Courtesy of FORD MOTOR CO.
- Is any AC voltage indicated?
- Yes : GO to J6.
- No : GO to J2.
J2 CHECK CIRCUIT 75-AD15 (YE/BU) FOR VOLTAGE
- Key in OFF position.
- Disconnect: Rear View Mirror C911.
- Key in ON position.
- Measure the voltage between the rear view mirror C911-13, circuit 75-AD15 (YE/BU), harness side and ground.
  
  Fig 2: Checking Circuit 75-AD15 (YE/BU) For Voltage
  Courtesy of FORD MOTOR CO.
- Is the voltage greater than 10 volts?
- Yes : GO to J3.
- No : REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
J3 CHECK CIRCUIT 31-AD15 (BK) FOR AN OPEN
- Key in OFF position.
- Measure the resistance between the rear view mirror C911-2, circuit 31-AD15 (BK/OG), harness side and ground.
  
  Fig 3: Checking Circuit 31-Ad15 (BK) For Open
  Courtesy of FORD MOTOR CO.
- Is the resistance less than 5 ohms?
- Yes : GO to J4.
- No : REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.

J4 CHECK CIRCUITS 8-MC8 (WH/RD) AND 9-MC8 (BN/RD) FOR AN OPEN AND A SHORT TO GROUND

Measure the resistances between the navigation system module C4209 pins, harness side and the rear view mirror C911 pins, harness side; and between the navigation system module C4209 pins, harness side and ground as follows:

Navigation System Module Pin	Rear View Mirror Pin	Circuit
C4209-7	C911-9,	8-MC8 (WH/RD)
C4209-19	C911-10	9-MC8 (BN/RD)

Fig 4: Checking Circuits 8-MC8 (WH/RD) And 9-MC8 (BN/RD) For Open And Short To Ground

Courtesy of FORD MOTOR CO.

Are the resistances less than 5 ohms between the navigation system module and the rear view mirror; and greater than 10,000 ohms between the navigation system module and ground?

Yes : GO to J5.
No : REPAIR the circuit in question. CLEAR the DTCs. REPEAT the self-test.

J5 CHECK CIRCUITS 8-MC8 (WH/RD) AND 9-MC8 (BN/RD) FOR A SHORT TO VOLTAGE
- Key in ON position.
- Measure the voltage between the navigation system module C4209-7, circuit 8-MC8 (WH/RD), harness side and ground; and between the navigation system module C4209-19, circuit 9-MC8 (BN/RD), harness side and ground.
  
  Fig 5: Checking Circuits 8-MC8 (WH/RD) And 9-MC8 (BN/RD) For Short To Voltage
  Courtesy of FORD MOTOR CO.
- Is any voltage indicated?
- Yes : REPAIR the circuit in question. CLEAR the DTCs. REPEAT the self-test.
- No : INSTALL a new rear view mirror. REFER to REAR VIEW MIRRORS . CLEAR the DTCs. REPEAT the self-test.
J6 CHECK FOR CORRECT NAVIGATION SYSTEM MODULE OPERATION
- Disconnect all the navigation system module connectors.
- Check for:
  - corrosion
  - pushed-out pins
- Connect all the navigation system module connectors and make sure they seat correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?
- Yes : INSTALL a new navigation system module. REFER to NAVIGATION SYSTEM MODULE in this article. TEST the system for normal operation.
- No : The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the self-test.