P1820

DTC P1820: Shift Fork Position Sensor 1 System (Voltage low range out)

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 voltage of the shift fork position sensor 1 is normal.

DESCRIPTIONS OF MONITOR METHODS
The voltage of the shift fork position sensor 1 is too low.

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)
^ P1821: Shift fork position sensor 1 system (voltage high range out)
^ P1822: Shift fork position sensor 1 system (Output range out)
^ P1823: Shift fork position sensor 1 system (Neutral)
^ P1824: Shift fork position sensor 1 system (Poor performance)
^ P1836: Shift fork 1 malfunction
^ P1852: Shift fork 1 or 2 opposite direction movement
^ P1855: Shift fork 3 or 4 opposite direction movement
^ P1857: Odd number gear axle interlock
^ P1876: Gear block 1st
^ P1877: Gear block 2nd
^ P1878: Gear block 3rd
^ P1879: Gear block 4th
^ P187A: Gear block 5th
^ P187B: Gear block 6th
^ P187C: Gear block reverse

Sensor (The sensor below is determined to be normal)
^ Not applicable

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.

JUDGMENT CRITERIA
^ Position sensor voltage: 0.128 V or less. (160 millisecond)

OBD-II DRIVE CYCLE PATTERN
The position sensor voltage remains 0. 128 V or more for 160 milliseconds.

PROBABLE CAUSES
^ Malfunction of TC-SST-ECU
^ Malfunction of shift fork position sensor 1

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

STEP 2. Check whether the DTC is reset.
Q: Is DTC No. P1820 set?
YES: Go to Step 3.
NO: Intermittent malfunction.

STEP 3. Scan tool Teach-in
1) Carry out the Item No. 1: Plausibility check. Teach-In Reference Table
2) After Teach-In, check which result ("Yes" or "No") is displayed in the Data list No. 101: Normal End. Teach-In Reference Table
Q: Which is displayed, "Yes" or "No"?
"Yes": Replace the transaxle assembly.
"No": Go to Step 4.

STEP 4. Replace the mechatronic assembly, and check if the DTC is reset.
1) Replace the mechatronic assembly.
2) Perform a test run of the vehicle.
3) Check the DTC.
Q: Is DTC No. P1820 set?
YES: Replace the transaxle assembly.
NO: This diagnosis is complete.