P1881

DTC P1881: Twin clutch SST control mode switch system (Malfunction)

CAUTION
^ If there is any problem in the CAN bus lines, an incorrect diagnostic trouble code may be set. Prior to this diagnosis, diagnose the CAN bus lines.
^ Whenever the ECU is replaced, ensure that the CAN bus lines are normal.

DIAGNOSTIC FUNCTION
TC-SST-ECU checks that the twin clutch SST control mode switch is normal.

DESCRIPTIONS OF MONITOR METHODS
"+" and signals of the twin clutch SST control mode switch is determined to be stuck on.

PROBABLE CAUSES
^ Twin clutch SST control mode switch malfunction
^ Malfunction of TC-SST-ECU

DIAGNOSTIC PROCEDURE

Required Special Tools:
^ 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. Scan tool CAN bus diagnostics
Using scan tool MB991958, diagnose the CAN bus lines.
Q: Is the check result normal?
YES: Go to Step 2.
NO: Repair the CAN bus lines. (Refer to Troubleshooting CAN Bus Diagnostics Table.) After repairing the CAN bus line, go to Step 2.

STEP 2. Check whether the DTC is reset.
After 5 or more seconds have passed with the engine idle status, check that the DTC is reset.
Q: Is DTC No. P1881 set?
YES: Go to Step 3.
NO: Intermittent malfunction. (Refer to How to Cope with Intermittent Malfunction How to Use Troubleshooting/Inspection Service Points.)

STEP 3. Twin clutch SST control mode switch check
Q: Is the check result normal?
YES: Go to Step 4.
NO: Replace the twin clutch SST control mode switch.

STEP 4. Shift lever assembly replacement
1) Replace the shift lever assembly.
2) Check if the DTC is set.
Q: Is DTC No. P1881 set?
YES: Replace the mechatronic assembly.
NO: Intermittent malfunction. (Refer to How to Cope with Intermittent Malfunction How to Use Troubleshooting/Inspection Service Points.)