P1857

DTC P1857: Odd number gear axle interlock

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 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. CAN Bus Diagnostics Chart.) 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 Replace the transaxle assembly. (Refer to Removal and Replacement.)
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 Replace the transaxle assembly. (Refer to Removal and Replacement.)
NO Intermittent malfunction. How to Cope With Intermittent Malfunctions.)