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DTC P1870: Engine torque signal abnormality


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 receives the periodic communication data from the engine control module via the CAN bus lines, and checks the data for abnormality.

DESCRIPTIONS OF MONITOR METHODS


The engine torque signal from the engine control module is determined to be abnormal.

MONITOR EXECUTION



MONITOR EXECUTION CONDITIONS (OTHER MONITOR AND SENSOR)


Other Monitor (There is no temporary DTC stored in memory for the item monitored below)
Sensor (The sensor below is determined to be normal)

LOGIC FLOW CHARTS (Monitor Sequence)




DTC SET CONDITIONS


Check Conditions
JUDGMENT CRITERIA

OBD-II DRIVE CYCLE PATTERN


Receives the normal value of the engine torque signal, or the parity/toggle are normal for 2 seconds.

PROBABLE CAUSES



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 the scan tool, diagnose the CAN bus lines.

Q. Is the check result normal?
Go to Step 2.
Repair the CAN bus lines. (Refer to GROUP 54C - Troubleshooting .) After repairing the CAN bus line, go to Step 2.

STEP 2. Scan tool diagnostic trouble code.
Check if the diagnostic trouble code is set to the system other than TC-SST.

Q. Is the DTC set?
Perform the relevant troubleshooting.
Go to Step 3.

STEP 3. Scan tool diagnostic trouble code.
After 15 seconds with the engine idle status, check that the diagnostic trouble code for engine is set. (Refer to GROUP 13B - Troubleshooting .)

Q. Is the DTC set?
Perform the relevant troubleshooting.
Go to Step 4.

STEP 4. Check whether the DTC is reset.
After 15 seconds with the engine idle status, check that the DTC is reset.

Q. Is DTC No.P1870 set?
Replace the transaxle assembly. (Refer to .)
Intermittent malfunction. (Refer to GROUP 00 - How to Cope with Intermittent Malfunction .)