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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 9-16 volts.
 
 
DIAGNOSTIC FUNCTION AND TROUBLE JUDGMENT
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
  • Malfunction of blind spot warning switch (stuck on)
  • Malfunction of gateway-ECU
  • Malfunction of BSW-ECU (master)
  • Damaged harness wires and connectors
 
 
 
DIAGNOSIS
Required Special Tools:
  • MB991223: Harness Set
  • MB992006: Extra Fine Probe
STEP 1. Using scan tool (M.U.T.-III), check 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
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
Item No.Item nameNormal condition
Item 5BSW SWOFF
OK: Normal condition is displayed.
Is the check result normal?
Go to Step 5.
: Go to Step 2.
 
STEP 2. Check of short to ground in DI05 line between gateway-ECU connector and blind spot warning switch connector.
Is the check result normal?
Go to Step 3.
Repair the connector(s) or wiring harness.
 
STEP 3. Check the blind spot warning switch.
Refer to blind spot warning switch Inspection .
Is the check result normal?
Go to Step 4.
Replace the blind spot warning switch.
 
STEP 4. Using scan tool (M.U.T.-III), check other system data list.
Using the gateway-ECU data list, check the blind spot warning switch signal.
(1)
  • When the blind spot warning switch is pressed.
 
Item No.Item nameNormal condition
Item 5BSW SWON
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
Item No.Item nameNormal condition
Item 5BSW SWOFF
OK: Normal condition is displayed.
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 gateway-ECU.
 
STEP 5. Using scan tool (M.U.T.-III), read the BSW-ECU (master) DTC 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).
The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction ).