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DTC C2321 BSW SW input malfunction
 
 
cautionBefore replacing the ECU, ensure that the power supply circuit, the ground circuit and the communication circuit are normal.
 
 
OPERATION
BSW-ECU (master) receives a signal from the blind spot warning switch via CAN communication with the gateway-ECU.
 
 
CHECK CONDITION
When all of the conditions below are satisfied:
  • Ignition switch is in the ON position.
  • BSW-ECU (master) system voltage is at 9 to 16 volts.
 
 
DIAGNOSTIC FUNCTION AND JUDGMENT CRITERIA
If the gateway-ECU detects the blind spot warning switch pressed state for 60 seconds or more continuously, the BSW-ECU (master) sets DTC C2321.
 
 
TROUBLESHOOTING HINTS
  • The blind spot warning switch (stuck on) may be defective
  • The gateway-ECU may be defective
  • The BSW-ECU (master) may be defective
  • The wiring harness or connectors may have loose, corroded, or damaged terminals, or terminals pushed back in the connector
 
 
DIAGNOSIS
Required Special Tools:
  • MB991223: Harness Set
  • MB992006: Extra Fine Probe
STEP 1. Using scan tool (M.U.T.-III) other system data list
Using the gateway-ECU data list, check the blind spot warning switch signal.
(1)
cautionTo prevent damage to scan tool (M.U.T.-III), always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool (M.U.T.-III).
Connect scan tool (M.U.T.-III). Refer to "How to connect Scan Tool (M.U.T.-III) ."
(2) Check the input signals from the blind spot warning switch.
  • When the blind spot warning switch is pressed.
 
Item No.Item nameNormal condition
Item 5BSW SWON
  • When the blind spot warning switch is not pressed.
 
Item No.Item nameNormal condition
Item 5BSW SWOFF
OK: Normal condition is displayed.
Is the check result normal?
Go to Step 6.
Go to Step 2.
 
STEP 2. Connectors check: gateway-ECU connector C-49, blind spot warning switch connector C-50.
Are gateway-ECU connector C-49 and blind spot warning switch connector C-50 in good condition?
Go to Step 3.
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 3. Check the wiring harness between gateway-ECU connector C-49 (terminal No. 21) and blind spot warning switch connector C-50 (terminal No. 3).
  • Check the input line for short and open circuit.
Is the wiring harness between Gateway-ECU connector C-49 (terminal 21) and blind spot warning switch connector C-50 (terminal 3) in good condition?
Go to Step 4.
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 blind spot warning switch.
Refer to blind spot warning switch Inspection .
Is the check result normal?
Go to Step 5.
Replace the blind spot warning switch.
 
STEP 5. Using scan tool (M.U.T.-III) other system data list
Using the gateway-ECU data list, check the blind spot warning switch signal.
  • When the blind spot warning switch is pressed.
 
Item No.Item nameNormal condition
Item 5BSW SWON
  • When the blind spot warning switch is not pressed.
 
Item No.Item nameNormal condition
Item 5BSW SWOFF
OK: Normal condition is displayed.
Is the check result normal?
Intermittent malfunction is suspected (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction ).
Replace the gateway-ECU.
 
STEP 6. Check whether the DTC is set again.
Check again if the DTC is set in the BSW-ECU (master).
(1) Erase the DTC.
(2) Turn the ignition switch from the "LOCK" (OFF) position to the "ON" position.
(3) Check if the DTC is set.
Is the DTC set?
Replace the BSW-ECU (master).
Intermittent malfunction is suspected (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction ).