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Inspection Procedure 4: Tone alarm does not sound normally.
 
 
cautionBefore replacing the combination meter, be sure to check that the power supply circuit, ground circuit, and communication circuit are normal.
 
 
 
 
TECHNICAL DESCRIPTION (COMMENT)
When the following signals are received via the CAN communication, the combination meter sounds the incorporated tone alarm according to the each pattern.
Keyless operation key reminder tone alarm function (vehicles with KOS)
  • Ignition switch OFF signal
  • IG knob push switch ON signal
  • Driver's door switch ON signal
Ignition key reminder tone alarm function (vehicles without KOS)
  • Ignition switch OFF signal
  • Key reminder switch OFF signal
  • Driver's door switch ON signal
Light reminder tone alarm function
  • Ignition switch OFF signal
  • Lighting switch ON signal
  • Driver's door switch ON signal
Door-ajar warning tone alarm function
  • Ignition switch ON signal
  • Any door switch or liftgate switch ON signal
  • Vehicle speed signal
Freeze warning tone alarm
  • Ignition switch ON signal
  • Ambient temperature signal
Multi information display interrupt display tone alarm
  • Display condition signal of information display from each warning (When there is a fixed tone alarm sounding pattern for each warning, that pattern has the priority.)
Meter information switch operation tone alarm
  • ON signal for combination meter information switch
Turn-signal light tone alarm function
  • Turn-signal light switch ON signal
Paddle shift cancel tone alarm, Theft-alarm function, ETACS-ECU function customize tone alarm, A/C operation tone alarm
  • Sounding request signal from the ETACS-ECU
FCM collision warning tone alarm/FCM approaching warning tone alarm
  • Sounding request signal from the FCM/LDW/AHB-ECU
LDW warning tone alarm
  • Sounding request signal from the FCM/LDW/AHB-ECU
BSW tone alarm <Vehicles with BSW (with LCA)/RCTA>
  • Sounding request signal from the BSW-ECU
RCTA tone alarm <Vehicles with BSW (with LCA)/RCTA>
  • Sounding request signal from the BSW-ECU
If the tone alarm does not sound normally, the connector(s) and wiring harness in the CAN bus lines, or the combination meter may have a problem.
 
 
TROUBLESHOOTING HINTS
  • The combination meter may be defective
  • The each ECU may be defective
 
 
DIAGNOSIS
STEP 1. Using scan tool MB991958, diagnose the CAN bus line.
(1)
cautionTo prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
Connect scan tool MB991958. Refer to "How to connect the Scan Tool (M.U.T.-III) ."
(2) Turn the ignition switch to the "ON" position.
(3) Diagnose the CAN bus line.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Is the CAN bus line found to be normal?
Go to Step 2.
Repair the CAN bus line (Refer to GROUP 54C, Diagnosis ).
 
STEP 2. Using scan tool MB991958, read the combination meter diagnostic trouble code.
Check if DTC is set in the combination meter.
Is the DTC set?
Troubleshoot the combination meter (Refer to ).
Go to Step 3.
 
STEP 3. Using scan tool MB991958, read for any diagnostic trouble code.
Check if diagnostic trouble code is set in the CVT, WCM, KOS-ECU, ETACS-ECU, FCM/LDW/AHB-ECU and A/C-ECU.
Is the DTC set in the any of the above?
<Set in the CVT.> : Troubleshoot the CVT (Refer to GROUP 23A, Diagnosis ).
<Set in the WCM.> : Troubleshoot the WCM (Refer to GROUP 42C, Diagnosis ).
<Set in the KOS.> : Troubleshoot the KOS (Refer to GROUP 42B, Diagnosis ).
<Set in the ETACS.> : Troubleshoot the ETACS (Refer to ).
<Set in the FCM/LDW/AHB-ECU.> : Troubleshoot the FCM and LDW (Refer to ).
<Set in the BSW-ECU.> : Troubleshoot the BSW (with LCA)/RCTA, refer to .
<Set in the A/C.> : Troubleshoot the A/C (Refer to GROUP 55A, Manual A/C Diagnosis or GROUP 55B, Automatic A/C Diagnosis ).
Go to Step 4.
 
STEP 4. Check by scan tool MB991958 "Special Function"
Using scan tool MB991958, select "Test" from the special function of the combination meter. Execute the following item to check the tone alarm.
  • Item 3: Buzzer(AUTO)
Is the check result normal?
Go to Step 5.
Replace the combination meter.
 
STEP 5. Retest the system
Check that the tone alarm sounds normally.
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 ).
Replace the combination meter.