Inspection Procedure
1: Hands-free cellular phone system does not work normally.
caution
Before replacing the ECU, ensure
that the power supply circuit, the earth circuit and the communication circuit are normal.
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-ECU. Then the signal is transmitted
from the hands-free-ECU to the cellular phone. The voice of other party is transmitted from
the cellular phone to the hands-free-ECU. Then, the voice is transmitted from the hands-free-ECU
to the audio unit <vehicles without MMCS> or audio visual navigation unit <vehicles
with MMCS>, and output from the speaker.
COMMENTS ON TROUBLE SYMPTOM
If the hands-free system cannot be used normally, the hands-free-ECU, microphone unit,
steering voice-control switch, or audio unit <vehicles without MMCS> or audio visual navigation
unit <vehicles with MMCS> may be defective.
PROBABLE CAUSES
Malfunction of the hands-free-ECU
Malfunction of the microphone unit
Malfunction of the steering voice-control switch
Malfunction of the audio unit <vehicles without MMCS> or audio visual navigation
unit <vehicles with MMCS>
Damaged harness wires and connectors
DIAGNOSIS PROCEDURE
STEP 1. Check the cellular phone.
Check that the cellular phone can be used normally as a unit.
Q.
Is the check result normally?
Go to Step 2.
Repair or replace the cellular phone.
STEP 2. Temporarily replace the cellular phone, and check the trouble
symptom.
Temporarily register a separate Bluetooth™-supported cellular phone, and check
that the hands-free cellular phone system operates normally.
Q.
Is the check result normally?
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-ECU.
Go to Step 3.
STEP 3. M.U.T.-III CAN bus diagnostics
Use the M.U.T.-III to diagnose the CAN bus lines.
Q.
Is the check result normal?
Go to Step 4.
Repair the CAN bus line (Refer to GROUP 54C -
Troubleshooting ).
STEP 5. Resistance measurement at C-122 hands-free-ECU connector.
(1)Disconnect the connector, and measure at the wiring harness side.
(2)Check the continuity between C-122 hands-free-ECU connector terminal No.15 and
body earth. OK: Continuity exists (2 Ω
or less)
Q.
Is the check result normal?
Go to Step 7.
Go to Step 6.
STEP 6. Check the wiring harness between C-122 hands-free-ECU connector
terminal No.15 and body earth.
Q.
Is the check result normal?
The trouble can be an intermittent malfunction (Refer to GROUP 00 -
How
to use Troubleshooting/inspection Service Points -
How to Cope with Intermittent
Malfunction ).
Repair the wiring harness.
STEP 7. Voltage measurement at C-122 hands-free-ECU connector.
(1)Disconnect the connector, and measure at the wiring harness side.
(2)Measure the voltage between terminal 13 and body earth. OK: Battery positive voltage
Q.
Is the check result normal?
Go to Step 9.
Go to Step 8.
STEP 8. Check the wiring harness between C-122 hands-free-ECU connector
terminal No.13 and C-317 ETACS-ECU connector terminal No.1.
Q.
Is the check result normal?
The trouble can be an intermittent malfunction (Refer to GROUP 00, How to use
Troubleshooting/inspection Service Points, How to Cope with Intermittent Malfunction ).
Repair the wiring harness.
STEP 9. Connector check: D-01 microphone unit connector
Q.
Is the check result normal?
Go to Step 10.
Repair the defective connector.
STEP 10. Check the wiring harness between C-122 hands-free-ECU connector
and D-01 microphone unit connector.
(1)Disconnect C-122 hands-free-ECU connector and D-01 microphone unit connector, and
check the wiring harness.
note
Prior to the wiring harness inspection, check C-40 intermediate connector, and repair
if necessary.
(2)Check the wiring harness between C-122 hands-free-ECU connector terminal No.1 and
D-01 microphone unit connector terminal No.22
(3)Check the wiring harness between C-122 hands-free-ECU connector terminal No.1 and
D-01 microphone unit connector terminal No.23
(4)Check the wiring harness between C-122 hands-free-ECU connector terminal No.2 and
D-01 microphone unit connector terminal No.24
Q.
Is the check result normal?
Go to Step 11.
Repair the wiring harness.
STEP 11. Connector check: C-16 audio unit connector <vehicles
without MMCS> or C-08 audio visual navigation unit connector <vehicles with MMCS>
Q.
Is the check result normal?
Go to Step 12.
Repair the defective connector.
STEP 12. Check the wiring harness between C-122 hands-free-ECU connector
and C-16 audio unit connector <vehicles without MMCS> or C-08 audio visual navigation unit
connector <vehicles with MMCS>.
(1)Disconnect C-122 hands-free-ECU connector and C-14 audio unit connector <vehicles
without MMCS> or C-07 audio visual navigation unit connector <vehicles with MMCS>, and check
the wiring harness.
note
Prior to the wiring harness inspection, check C-17 intermediate connector, and repair
if necessary. <vehiles with MMCS>
(2)Check the wiring harness between C-122 hands-free-ECU connector terminal No.9 and
C-14 audio unit connector terminal No.3 <vehicles without MMCS>
(3)Check the wiring harness between C-122 hands-free-ECU connector terminal No.19
and C-14 audio unit connector terminal No.2 <vehicles without MMCS>
(4)Check the wiring harness between C-122 hands-free-ECU connector terminal No.21
and C-14 audio unit connector terminal No.2 <vehicles without MMCS>
(5)Check the wiring harness between C-122 hands-free-ECU connector terminal No.9 and
C-07 audio visual navigation unit connector terminal No.45 <vehicles without MMCS>
(6)Check the wiring harness between C-122 hands-free-ECU connector terminal No.19
and C-07 audio visual navigation unit connector terminal No.46 <vehicles without MMCS>
(7)Check the wiring harness between C-122 hands-free-ECU connector terminal No.21
and C-07 audio visual navigation unit connector terminal No.46 <vehicles without MMCS>
Q.
Is the check result normal?
Go to Step 13.
Repair the wiring harness.
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 check result normal?
Replace the microphone unit.
Go to Step 14.
STEP 14. Temporarily replace the hands-free-ECU, and check the trouble
symptom.
Check that the normal conversation is possible with the hands-free system.
Q.
Is the check result normal?
Replace the hands-free-ECU.
Replace the audio unit <vehicles without MMCS> or audio visual navigation
unit <vehicles with MMCS>.