Inspection Procedure 1
Inspection Procedure 1: Hands-free cellular phone system does not work normally.Hands Free Module Power Supply Circuit:
Hands Free Cellular Phone System Circuit Part 1:
Hands Free Cellular Phone System Circuit Part 2:
FUNCTION
During the conversation with the hands-free system, the signal of speaker's voice is transmitted from the microphone unit to the hands-free module. Then the signal is transmitted from the hands-free module to the cellular phone. The voice of other party is transmitted from the cellular phone to the hands-free module. Then, the voice is transmitted from the hands-free module to the radio and CD changer
TROUBLE JUDGMENT CONDITIONS
If the hands-free system cannot be used normally, the hands-free module, microphone unit, steering voice control switch, or radio and CD changer
TROUBLESHOOTING HINTS
- Malfunction of the hands-free module
- Malfunction of the microphone unit
- Malfunction of the steering voice-control switch
- Malfunction of the radio and CD changer
- Damaged harness wires and connectors
DIAGNOSIS
Required Special Tools:
- MB991223: Harness Set
- MB992006: Extra Fine Probe
STEP 1. Check the cellular phone.
Check that the cellular phone can be used normally as a unit.
Q: Is it possible to use the cellular phone normally?
YES: Go to Step 2.
NO: Repair or replace the cellular phone.
STEP 2. Temporarily replace the cellular phone, and check the trouble symptom.
Temporarily register a separate Bluetooth (TM) supported cellular phone, and check that the hands-free cellular phone system operates normally.
Q: Is the normal conversation possible with the hands-free system?
YES: Ask the customer to have the cellular phone repaired or replaced. Then, delete the temporarily registered cellular phone. Once the customer prepares the normally working cellular phone, register the cellular phone to the hands-free module.
NO: Go to Step 3.
STEP 3. Using scan tool MB991958, diagnose the CAN bus line.
Connect scan tool MB991958. Refer to "How to connect the Scan Tool (M.U.T.-III)."
1. Turn the ignition switch to "ON" position.
2. Diagnose the CAN bus line.
3. Turn the ignition switch to "LOCK" (OFF) position.
Q: Is the CAN bus line found to be normal?
YES: Go to Step 4.
NO: Repair the CAN bus line. (Refer to Information Bus, Troubleshooting.)
STEP 4. Check hands-free module connector C-121 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q: Are hands-free module connector C-121 in good condition?
YES: Go to Step 5.
NO: Repair or replace the damaged component(s). Refer to Harness Connector Inspection.
STEP 5. Check the ground circuit to the hands-free module. Measure the resistance at hands-free module connector C-121.
1. Disconnect hands-free module connector C-121, and measure at the wiring harness side.
2. Measure resistance between terminal 15 and ground.
OK: The resistance should be 2 ohms or less.
Q: Is the measured resistance 2 ohms or less?
YES: Go to Step 7.
NO: Go to Step 6.
STEP 6. Check the wiring harness between hands-free module connector C-121 (terminal 15) and ground.
Q: Is the wiring harness between hands-free module connector C-121 (terminal 15) and ground in good condition?
YES: The trouble can be an intermittent malfunction (Refer to How to use Troubleshooting/Inspection Service Points, How to Cope with Intermittent Malfunction).
NO: The wiring harness may be damaged or the connector (s) may have loose, corroded or damaged terminals, or terminals pushed back in the connector. Repair the wiring harness as necessary.
STEP 7. Check the power supply circuit to the hands-free module. Measure the voltage at hands-free module connector C-121.
1. Disconnect hands-free module connector C-121, and measure the voltage available at the hands-free module side of the connector.
2. Measure the voltage between terminal 13 and ground.
OK: The voltage should measure approximately 2 volts (battery positive voltage).
Q: Is the measured voltage approximately 2 volts (battery positive voltage)?
YES: Go to Step 9.
NO: Go to Step 8.
STEP 8. Check the wiring harness between hands-free module connector C-121 (terminal 13) and ETACS-ECU connector C-317 (terminal 1).
Q: Is the wiring harness between hands-free module connector C-121 (terminal 13) and ETACS-ECU connector C-317 (terminal 1) in good condition?
YES: The trouble can be an intermittent malfunction (Refer to How to use Troubleshooting/Inspection Service Points, How to Cope with Intermittent Malfunction).
NO: The wiring harness may be damaged or the connector (s) may have loose, corroded or damaged terminals, or terminals pushed back in the connector. Repair the wiring harness as necessary.
STEP 9. Check microphone unit connector D-01 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q: Is microphone unit connector D-01 in good condition?
YES: Go to Step 10.
NO: Repair or replace the damaged component(s). Refer to Harness Connector Inspection.
STEP 10. Check the wiring harness between hands-free module connector C-121 and microphone unit connector D-01.
1. Disconnect hands-free module connector C-121 and microphone unit connector D-01, and check the wiring harness.
NOTE: Also check intermediate connector C-36 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If intermediate connector C-36 is damaged, repair or replace the connector as described in, Harness Connector Inspection.
2. Check the wiring harness between hands-free module connector C-121 (terminal No.1) and microphone unit connector D-01 (terminal No.22)
3. Check the wiring harness between hands-free module connector C-121 (terminal No.1) and microphone unit connector D-01 (terminal No.23)
4. Check the wiring harness between hands-free module connector C-121 (terminal No.2) and microphone unit connector D-01 (terminal No.24)
Q: Is the wiring harness between hands-free module connector C-121 and microphone unit connector D-01 in good condition?
YES: Go to Step 11.
NO: The wiring harness may be damaged or the connector (s) may have loose, corroded or damaged terminals, or terminals pushed back in the connector. Repair the wiring harness as necessary.
STEP 11. Check radio and CD changer connector C-14
Q: Is radio and CD changer connector C-14
YES: Go to Step 12.
NO: Repair or replace the damaged component(s). Refer to Harness Connector Inspection.
STEP 12. Check the wiring harness between hands-free module connector C-121 and radio and CD changer connector C-14
1. Disconnect hands-free module connector C-121 and radio and CD changer connector C-14
NOTE: Also check intermediate connector C-15 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If intermediate connector C-15 is damaged, repair or replace the connector as described in, Harness Connector Inspection.
2. Check the wiring harness between hands-free module connector C-121 (terminal No.9) and radio and CD changer connector C-14 (terminal No.3)
3. Check the wiring harness between hands-free module connector C-121 (terminal No.19) and radio and CD changer connector C-14 (terminal No.2)
4. Check the wiring harness between hands-free module connector C-121 (terminal No.21) and radio and CD changer connector C-14 (terminal No.2)
5. Check the wiring harness between hands-free module connector C-121 (terminal No.9) and audio visual navigation unit connector C-07 (terminal No.45)
6. Check the wiring harness between hands-free module connector C-121 (terminal No.19) and audio visual navigation unit connector C-07 (terminal No.46)
7. Check the wiring harness between hands-free module connector C-121 (terminal No.21) and audio visual navigation unit connector C-07 (terminal No.46)
Q: Is the wiring harness between hands-free module connector C-121 and radio and CD changer connector C-14
YES: Go to Step 13.
NO: The wiring harness may be damaged or the connector (s) may have loose, corroded or damaged terminals, or terminals pushed back in the connector. Repair the wiring harness as necessary.
STEP 13. Temporarily replace the microphone unit, and check the trouble symptom.
Check that the normal conversation is possible with the hands-free system.
Q: Is the normal conversation possible with the hands-free system?
YES: Replace the microphone unit.
NO: Go to Step 14.
STEP 14. Temporarily replace the hands-free module, and check the trouble symptom.
Check that the normal conversation is possible with the hands-free system.
Q: Is the normal conversation possible with the hands-free system?
YES: Replace the hands-free module.
NO: Replace the radio and CD changer