P187A
DTC P187A: Gear Block 5thCAUTION
^ 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 engagement of the 5th gear is determined to be impossible.
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
^ Engine speed: 650 r/min or more.
^ Time since above engine condition: 1.5 seconds or more.
^ Target gear: 5th gear.
JUDGMENT CRITERIA
^ Gear (synchro) engagement: 3 times blocked. (immediately)
OBD-II DRIVE CYCLE PATTERN
The 5th gear is engaged.
PROBABLE CAUSES
^ Malfunction of TC-SST-ECU
^ Malfunction of TC-SST gear
^ Malfunction of clutch assembly
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) Drive with shifted in the 5th gear.
3) Check that the DTC is reset.
Q: Is DTC No. P187A set?
YES: Go to Step 3.
NO: Intermittent malfunction.
STEP 3. Scan tool Teach-in
1) Carry out the Item No.3: Line pressure Test. 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": Go to Step 4
"No" DTC No. P181B: Carry out the troubleshooting for the DTC No. P181B: Clutch 1 (Pressure low range out). P181B
STEP 4. Replace the clutch assembly, and check if the DTC is reset.
1) Replace the clutch assembly.
2) Drive with shifted in the 5th gear.
3) Check the DTC.
Q: Is DTC No. P187A set?
YES: Replace the transaxle assembly.
NO: This diagnosis is complete.