P1872

DTC P1872: Between shift lever and TC-SST system (Q-A function abnormality)

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 shift lever-ECU is normal.

DESCRIPTIONS OF MONITOR METHODS

The shift lever-ECU is determined to be abnormal.

PROBABLE CAUSES

- Malfunction of the shift lever-ECU
- 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 Shift Lever.)

Q. Is the DTC set?

YES Perform the relevant troubleshooting.
NO Go to Step 3.
STEP 3. 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.

Q. Is DTC No. P1872 set?

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