P1857
DTC P1857: Odd number gear axle interlockCAUTION
^ 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 gear engagement is normal.
DESCRIPTIONS OF MONITOR METHODS
The two gears are determined to be engaged in the odd number gear range.
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)
^ Not applicable
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.
^ Engine speed: 650 r/min or more.
^ Time since above engine condition: 1.5 seconds or more.
JUDGMENT CRITERIA
^ Shift fork 1 and 2 position: 3.8 mm (0.15 inch) or more. (500 millisecond)
OBD-II DRIVE CYCLE PATTERN
The shift fork 1 and 2 positions remain 3.8 mm (0.15 inch) or less for 500 millisecond.
PROBABLE CAUSES
^ Malfunction of TC-SST-ECU
^ Malfunction of TC-SST gear
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.
1) Erase the DTC.
2) With the ignition switch ON, operate the shift lever in the following sequence: P ->R ->D ->R ->P. (Hold each range for 5 seconds or more.)
3) Check that the DTC is reset.
Q: Is DTC No. P1857 set?
YES: Go to Step 4.
NO: Go to Step 3.
STEP 3. Check whether the DTC is reset.
1) Drive with shifting to each gear range. (Hold each gear range for 5 seconds or more.)
2) Check that the DTC is reset.
Q: Is DTC No. P1857 set?
YES: Go to Step 4.
NO: Intermittent malfunction.
STEP 4. Scan tool diagnostic trouble code.
Check if any code from P1836, P183D, P1844, or P184B is set in addition to the diagnostic trouble code No. P1857.
Q: Check if any code from P1836, P183D, P1844, or P184B is set in addition to the diagnostic trouble code No. P1857.
YES: Replace the mechatronic assembly.
NO: Replace the transaxle assembly.