Traction Control System (Tcl)

DTC U1100: ECM or PCM time-out (related to engine)

CAUTION:
^ If DTC U1100 is set in the ABS/TCL-ECU, always diagnose the CAN main bus line. If there is any fault in the CAN bus lines, an incorrect DTC may be set.
^ Whenever the ABS/TCL-ECU is replaced, ensure that the communication circuit is normal.

DTC SET CONDITION
The ABS/TCL-ECU receives engine system-related signals from the ECM or PCM via CAN bus lines.

TROUBLESHOOTING HINTS (THE MOST LIKELY CAUSES FOR THESE DTCS ARE TO SET ARE:)
^ Damaged harness or connector.
^ Malfunction of the ECM.
^ Malfunction of the PCM .
^ Malfunction of the ABS/TCL-ECU.

DIAGNOSIS

Required Special Tools:
^ MB991958: Scan Tool (MUT-III Sub Assembly)
^ MB991824: V.C.I.
^ MB991827: MUT-III USB Cable
^ MB991910: MUT-III Main Harness A

STEP 1. Using scan tool MB991958, diagnose the CAN bus line.

CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.

1. Connect scan tool MB991958 to the data link connector.
2. Turn the ignition switch to the "ON" position.
3. Diagnose the CAN bus line.
4. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the CAN bus line found to be normal?
YES: Go to Step 2.
NO: Repair the CAN bus line. Then go to Step 6.

STEP 2. Using scan tool MB991958, read the diagnostic trouble code.

CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.

1. Erase the DTC.
2. Turn the ignition switch to the "ON" position.
3. Check for MFI system diagnostic trouble code.
4. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is any DTC set?
YES: Repair the MFI control system. Then go to Step 6.
NO: Go to Step 3.

STEP 3. Using scan tool MB991958, read the diagnostic trouble code.

CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.

1. Connect scan tool MB991958 to the data link connector.
2. Turn the ignition switch to the "ON" position.
3. Check if a DTC, which relates to CAN communication-linked systems below, is set.
ECM or PCM
^ DTC U1100: ECM or PCM time-out (related to engine).
ETACS-ECU
^ DTC 011: ECM or PCM time-out (related to engine).
Combination meter
^ DTC 011: ECM or PCM time-out (related to engine).
4. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is DTC 011 or U1100 set?
YES: Go to Step 4.
NO: Go to Step 5.

STEP 4. Using scan tool MB991958, read the diagnostic trouble code.

CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.

1. Connect scan tool MB991958 to the data link connector.
2. Turn the ignition switch to the "ON" position.
3. Check if the DTC is set.
4. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is DTC U1100 set?
YES: Replace the ECM or PCM . Then go to Step 6.
NO: It can be assumed that this malfunction is intermittent.

STEP 5. Using scan tool MB991958, read the diagnostic trouble code.

CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.

Check again if the DTC is set.
1. Turn the ignition switch to the "ON" position.
2. Erase the DTC.
3. Turn the ignition switch to the "LOCK" (OFF) position.
4. Turn the ignition switch to the "ON" position.
5. Check if the DTC is set.
6. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is DTC U1100 set?
YES: Replace the hydraulic unit (integrated with ABS/TCL-ECU). Then go to Step 6.
NO: It can be assumed that this malfunction is intermittent.

STEP 6. Using scan tool MB991958, read the diagnostic trouble code.

CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.

Check again if the DTC is set.
1. Turn the ignition switch to the "ON" position.
2. Erase the DTC.
3. Turn the ignition switch to the "LOCK" (OFF) position.
4. Turn the ignition switch to the "ON" position.
5. Check if the DTC is set.
6. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is DTC U1100 set?
YES: Return to Step 1.
NO: The procedure is complete.