P1803

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

SHIFT LEVER SYSTEM CIRCUIT





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)
^ P1851D: 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

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. After repairing the CAN bus line, go to Step 2.

STEP 2. Scan tool diagnostic trouble code
Check the shift lever diagnostic trouble code.

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 or short circuit.

Q: Is the check result normal?
YES: Go to Step 5.
NO: Repair the wiring harness.

STEP 5. Replace the shift lever assembly, and check if the diagnostic trouble code is reset.
1) Replace the shift lever assembly.
2) Check the DTC.

Q: Is DTC No. P1803 set?
YES: Replace the TC-SST assembly.
NO: Intermittent malfunction.