P1802

DTC P1802: Shift Lever System (LIN communication 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 CAN back-up communication (LIN) is normal.

DESCRIPTIONS OF MONITOR METHODS

The CAN back-up communication is determined to be abnormal.

PROBABLE CAUSES

- Malfunction of the shift lever-ECU
- Malfunction of the LIN bus
- 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. CAN Bus Diagnostics Chart.) After repairing the CAN bus line, go to Step 2.
STEP 2. Scan tool diagnostic trouble code

Check the shift lever diagnostic trouble code. (Refer to Twin Clutch-Sportronic Shift Transmission (TC-SST).)

Q. Is the DTC set?

YES Perform the relevant troubleshooting.
NO Go to Step 3.
STEP 3. Inspection of the TC-SST-ECU connector, intermediate connector, and shift lever-ECU connector: B-107, A-13, C-27

Check for the contact with terminals.

Q. Is the check result normal?

YES Go to Step 4.
NO Repair the defective connector.
STEP 4. Check the wiring harness between B-107 TC-SST-ECU connector terminal No. 17 and C-27 shift lever-ECU connector terminal No. 16.

Check the communication line for open and short circuit.

Q. Is the check result normal?

YES Go to Step 5.
NO Repair the wiring harness.
STEP 5. Check whether the DTC is reset.

10 seconds after turning ON the ignition switch, check that the DTC is reset.

Q. Is DTC No. P1802 set?

YES Go to Step 6.
NO This diagnosis is complete.
STEP 6. Replace the shift lever assembly, and check if the diagnostic trouble code is reset.

(1)Replace the shift lever assembly. (Refer to Service and Repair.)

(2)Check the DTC.

(3)After 10 or more seconds have passed with the ignition switch ON position, check that the DTC is reset.

Q. Is DTC No. P1802 set?

YES Replace the transaxle assembly. (Refer to Removal and Replacement.)
NO Intermittent malfunction. How to Cope With Intermittent Malfunctions.)