B2450
DTC B2450: Switch Panel CommunicationCAUTION: Before replacing the radio and CD player, be sure to check that the power supply circuit, ground circuit, and communication circuit are normal.
Center Panel Unit Power Supply Circuit:
TROUBLE JUDGMENT
If the radio and CD player cannot establish the communication with center panel assembly for 1 minute or more, the diagnostic trouble code is set.
COMMENTS ON TROUBLE SYMPTOM
The radio and CD player, center panel assembly, or CAN bus line may have a problem.
TROUBLESHOOTING HINTS
- The CAN bus line may be defective.
- The radio and CD player may be defective.
- The center panel unit may be defective.
DIAGNOSIS
Required Special Tools:
- MB991223: Harness Set
- MB992006: Extra Fine Probe
- MB991958 Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: Vehicle Communication Interface (V.C.I.)
- MB991827 M.U.T.-III USB Cable
- MB991910 M.U.T.-III Main Harness A
STEP 1. Using scan tool MB991958, diagnose the CAN bus line.
Use scan tool MB991958 to diagnose the CAN bus lines.
CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
1. Connect scan tool MB991958. Refer to "How to connect the Scan Tool (M.U.T.-III)." How to Connect the Scan Tool (M.U.T.-III)
2. Turn the ignition switch to "ON" position.
3. Diagnose the CAN bus line.
Q: Is the check result normal?
YES : Go to Step 2.
NO : Repair the CAN bus line.
STEP 2. Check center panel unit connector C-124 and radio and CD player connector C-109 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q: Are center panel unit connector C-124 and radio and CD player connector C-109 in good condition?
YES : Go to Step 3.
NO : Repair or replace the damaged component(s).
STEP 3. Check the wiring harness between center panel unit connector C-124 (terminal 1, 2) and radio and CD player connector C-109 (terminal 8, 18).
- Check the wiring harness for open circuit and short circuit.
Q: Is the wiring harness between center panel unit connector C-124 (terminal 1, 2) and radio and CD player connector C-109 (terminal 8, 18) in good condition?
YES : Go to Step 4.
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 4. Check the ground circuit to the center panel unit. Measure the resistance at center panel unit connector C-124.
1. Disconnect the connector, and measure at the wiring harness side.
2. Measure resistance between terminal 9 and ground.
OK: The resistance should be 2 ohms or less.
Q: Is the measured resistance 2 ohms or less?
YES : Go to Step 6.
NO : Go to Step 5.
STEP 5. Check the wiring harness between center panel unit connector C-124 (terminal 9) and ground.
- Check the ground wires for open circuit.
Q: Is the wiring harness between center panel unit connector C-124 (terminal 9) and ground in good condition?
YES : Go to Step 8.
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 6. Check the power supply circuit to the center panel unit. Measure the voltage at center panel unit connector C-124.
1. Disconnect the connector, and measure at the harness side connector.
2. Measure voltage between terminal 7 and ground.
OK: Battery positive voltage
Q: Is the measured voltage battery voltage?
YES : Go to Step 8.
NO : Go to Step 7.
STEP 7. Check the wiring harness between center panel unit connector C-124 (terminal 7) and fusible link 36.
- Check the power supply line for open circuit and short circuit.
NOTE: Also ETACS-ECU connector C-307, C-317 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If joint connector ETACS-ECU connector C-307, C-317 are damaged, repair or replace the connector.
Q: Is the wiring harness between center panel unit connector C-124 (terminal 7) and fusible link 36 in good condition?
YES : Go to Step 8.
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 8. Recheck for diagnostic trouble code.
Check again if the DTC is set to the radio and CD player
1. Erase the DTC.
2. Turn the ignition switch from "LOCK" (OFF) position to "ON" position.
3. Check if the DTC is set.
Q: Is the DTC set?
YES : Go to Step 9.
NO : The trouble can be an intermittent malfunction.
STEP 9. Recheck for diagnostic trouble code.
Temporarily replace the center panel unit, and recheck that the DTC is set to the radio and CD player.
1. Erase the DTC.
2. Turn the ignition switch from "LOCK" (OFF) position to "ON" position.
3. Check if the DTC is set.
Q: Is the DTC set?
YES : Replace the radio and CD player.
NO : Replace the center panel unit.