DTC P1803: Shift Lever System (CAN, LIN Time-out Error)

LIN COMMUNICATION SYSTEM CIRCUIT

Refer to

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 communication with the shift lever-ECU (CAN and LIN) is normal.

DESCRIPTIONS OF MONITOR METHODS

The CAN and LIN communication with the shift lever-ECU is determined to be abnormal.

MONITOR EXECUTION

Continuous

MONITOR EXECUTION CONDITIONS (OTHER MONITOR AND SENSOR)

Other Monitor (There is no temporary DTC stored in memory for the item monitored below)

P0841: Clutch 1 pressure sensor system (Poor performance)
P0842: Clutch 1 pressure sensor system (Output low range out)
P0843: Clutch 1 pressure sensor system (Output high range out)
P0846: Clutch 2 pressure sensor system (Poor performance)
P0847: Clutch 2 pressure sensor system (Output low range out)
P0848: Clutch 2 pressure sensor system (Output high range out)
P185D: Clutch open not possible
U0001: Bus off
U0100: Engine time-out error
P1870: Engine torque signal abnormality
P1871: APS system (Signal abnormality)
P1872: Between shift lever and TC-SST system (Q-A function abnormality)

Sensor (The sensor below is determined to be normal)

Clutch 1 pressure sensor
Clutch 2 pressure sensor
APS
Shift lever-ECU

LOGIC FLOW CHARTS (Monitor Sequence)

DTC SET CONDITIONS

Check Conditions

Voltage of battery: 8 V or more.
Voltage of battery: 16.5 V or less.
Time after TC-SST-ECU start: 5 seconds or more.

JUDGMENT CRITERIA

LIN communication with shift lever-ECU: Fail, and CAN communication with shift lever-ECU: Fail (Immediately).

OBD-II DRIVE CYCLE PATTERN

Receives LIN and CAN signal from shift lever-ECU.

PROBABLE CAUSES

Malfunction of the shift lever-ECU
Malfunction of the LIN bus
The CAN bus line is defective.
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?

	Go to Step 2.

	Repair the CAN bus lines. (Refer to GROUP 54C - Troubleshooting .) 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

Q. Is the DTC set?

	Perform the relevant troubleshooting.

	Go to Step 3.

STEP 3. Inspection of the TC-SST-ECU connector, intermediate connector, and shift lever-ECU connector: B-120, A-54, C-49

Check for the contact with terminals.

Q. Is the check result normal?

	Go to Step 4.

	Repair the defective connector.

STEP 4. Check the wiring harness between B-120 TC-SST-ECU connector terminal No. 17 and C-49 shift lever-ECU connector terminal No. 16.

Check the communication line for open and short circuit.

Q. Is the check result normal?

	Go to Step 5.

	Repair the wiring harness.

STEP 5. Check whether the DTC is reset.

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

Q. Is DTC No. P1803 set?

	Replace the shift lever assembly. (Refer to .)

	Intermittent malfunction. (Refer to GROUP 00 - How to Cope with Intermittent Malfunction .)