Mitsubishi L200. Manual — part 741

MITSUBISHI MULTI COMMUNICATION SYSTEM (MMCS)

CHASSIS ELECTRICAL

54A-331

Inspection Procedure 2: No sound is heard. <Vehicles with audio amplifier>

CAUTION

Whenever the multivision display is replaced,
ensure that the power supply circuit and the
earthing circuit are normal. (Check that the volt-
age is 10 V or more.)

Audio System Circuit

AUDIO AMPLIFIER

MULTIVISION DISPLAY

FUSIBLE
LINK

23

Wire colour code
B : Black LG : Light green G : Green L : Blue W : White Y : Yellow SB : Sky blue
BR : Brown O : Orange GR : Grey R : Red P : Pink V : Violet PU : Purple SI : Silver

NOTE

:LHD
:RHD

MITSUBISHI MULTI COMMUNICATION SYSTEM (MMCS)

CHASSIS ELECTRICAL

54A-332

TWEETER (LH)

TWEETER (RH)

FRONT DOOR
SPEAKER (LH)

FRONT DOOR
SPEAKER (RH)

Speaker System Circuit

AUDIO AMPLIFIER

REAR DOOR
SPEAKER (RH)

REAR DOOR
SPEAKER (LH)

Wire colour code
B : Black LG : Light green G : Green L : Blue W : White Y : Yellow SB : Sky blue
BR : Brown O : Orange GR : Grey R : Red P : Pink V : Violet PU : Purple SI : Silver

NOTE

:LHD
:RHD

MITSUBISHI MULTI COMMUNICATION SYSTEM (MMCS)

CHASSIS ELECTRICAL

54A-333

COMMENTS ON TROUBLE SYMPTOM
If the audio sound is not output, the multivision dis-
play, audio amplifier, or power supply circuit of audio
amplifier may have a problem. In addition, if any of
the speakers is short-circuited, the protection circuit
inside the multivision display disables all the speak-
ers to sound. Therefore, if all the speakers do not
output sound, the speaker circuit may be shorted or
the speaker may be defective. In some cases, the
sound is output depending on sources, thus use the
music server, radio, CD/DVD, and others to check if
the sound is output.
PROBABLE CAUSES

• Malfunctions of multivision display

• Malfunction of audio amplifier

• Malfunction of speaker

• Damaged wiring harness and connectors

DIAGNOSIS PROCEDURE

STEP 1. Check the multivision display operation.

Q: Check the sources from which the sound is not

output.

No sound only from radio :

Perform Inspection

Procedure 6 "The FM/MW/LM radio
broadcasting can not be received.." (Refer
to

P.54A-368

.)

No sound only when the CD is played :

Perform

Inspection Procedure 8 "CD/DVD cannot be
played." (Refer to

P.54A-371

.)

No sound only when the DVD is played :

Perform

Inspection Procedure 8 "CD/DVD cannot be
Played." (Refer to

P.54A-371

.) Or, perform

Inspection Procedure 9 "Image of a DVD is
Played, but no Sound is Played." (Refer to

P.54A-373

.)

No sound only when the music server is used :

Go

to Step 2.

No sound from any of the sources :

Go to Step 2.

STEP 2. Check the service data log for the MMCS
service mode.
(1) Display the service data log for the MMCS

service mode. (Refer to

P.54A-305

.)

(2) Check if the service data log for drive and HDD is

displayed.

Q: Is the service data log displayed?

AUDIO AMPLIFIER

MULTIVISION DISPLAY

Audio Amplifier System Circuit

Wire colour code
B : Black LG : Light green G : Green L : Blue W : White Y : Yellow SB : Sky blue
BR : Brown O : Orange GR : Grey R : Red P : Pink V : Violet PU : Purple SI : Silver

MITSUBISHI MULTI COMMUNICATION SYSTEM (MMCS)

CHASSIS ELECTRICAL

54A-334

YES (The service data log for drive is displayed.) :

Perform Inspection Procedure 8 "CD/DVD
cannot be Played." (Refer to

P.54A-371

.)

Or, perform Inspection Procedure 9 "Image
of a DVD is Played, but no Sound is
Played." (Refer to

P.54A-373

.) Then, go to

Step 3.

YES (The service data log for HDD is displayed.) :

Abnormalities relating to high or low
temperature may be present. Check if the
multivision display can output the sound at
the operable temperature. If it cannot output
the sound, go to Step 3.

NO :

Go to Step 3.

STEP 3. Perform "Network/Connect Line Check"
in the MMCS service mode.
(1) Display "Network/Connect Line Check" in the

MMCS service mode. (Refer to

P.54A-305

.)

(2) Check if "DVD Drive OK" is displayed.
(3) Check if "HDD Drive OK" is displayed.

Q: Is the check result normal?

YES :

Go to Step 4.

NO :

Go to Step 15.

STEP 4. Connector check: D-30, D-31 audio
amplifier connector

Q: Is the check result normal?

YES :

Go to Step 5.

NO :

Repair the defective connector.

STEP 5. Resistance measurement at D-30, D-31
audio amplifier connector
(1) Disconnect the connector, and measure at the

wiring harness side.

(2) Measure the resistance between D-30 audio

amplifier connector terminal No.33 and the body
earth.

OK: Continuity exists (2

Ω or less)

(3) Measure the resistance between D-30 audio

amplifier connector terminal No.34 and the body
earth.

OK: Continuity exists (2

Ω or less)

(4) Measure the resistance between D-31 audio

amplifier connector terminal No.3 and the body
earth.

OK: Continuity exists (2

Ω or less)

(5) Measure the resistance between D-31 audio

amplifier connector terminal No.4 and the body

earth.

OK: Continuity exists (2

Ω or less)

Q: Is the check result normal?

YES :

Go to Step 7.

NO :

Go to Step 6.

STEP 6. Check the wiring harness between the D-
30 audio amplifier connector terminal No.33, 34
or D-31 audio amplifier connector terminal No.3,
4 and the body earth

• Check the earth wires for open circuit.

NOTE: Prior to the wiring harness inspection, check
intermediate connector C-59, joint connectors C-137
and C-138, and repair if necessary.

Q: Is the check result normal?

YES :

Go to Step 7.

NO :

Repair the wiring harness.

STEP 7. Voltage measurement at D-31 audio
amplifier connector.
(1) Disconnect the connector, and measure at the

wiring harness side.

(2) Voltage between D-31 audio amplifier connector

terminal No.5 and the body earth

OK: System voltage

(3) Voltage between D-31 audio amplifier connector

terminal No.6 and the body earth

OK: System voltage

Q: Is the check result normal?

YES :

Go to Step 9.

NO :

Go to Step 8.

STEP 8. Check the wiring harness between D-31
audio amplifier connector terminal No.5, 6 and
fusible link No.23.

• Check the power supply lines for open circuit and

short circuit.

NOTE: Prior to the wiring harness inspection, check
intermediate connectors C-16, C-13 <LHD> and C-
14 <RHD>, and repair if necessary.

Q: Is the check result normal?

YES :

Go to Step 9.

NO :

Repair the wiring harness.

STEP 9. Connector check: C-168 multivision
display connector

Q: Is the check result normal?

YES :

Go to Step 10.

NO :

Repair the defective connector.