U1102

DTC U1102: ABS-ECU or TCL/ ASC-ECU time-out

CAUTION:
- If DTC U1102 is set in the combination meter, always diagnose the CAN bus lines.
- Whenever the ECU is replaced, ensure that the communication circuit is normal.

CIRCUIT OPERATION
Some instruments of the combination meter are linked to the CAN bus line. Both the combination meter and the ECM [M/T] or PCM [A/T] have a terminator resistor.

DTC SET CONDITIONS
The combination meter communicates with the ABS-ECU or TCL/ASC-ECU through CAN bus lines. If it cannot receive all the necessary signals from the ABS-ECU or TCL/ASC-ECU, DTC U1102 is set.

TECHNICAL DESCRIPTION (COMMENT)

CAUTION: If the ignition switch is turned to the "ON" position without starting the engine, DTC (past trouble) U1100, U1101 and U1102 may be set on the combination meter after one minute.

Current trouble
- Connector(s) or wiring harness in the CAN bus lines between the ABS-ECU or TCL/ASC-ECU and the combination meter, the power supply system to the ABS-ECU or TCL/ASC-ECU, the ABS-ECU or TCL/ASC-ECU itself, or the combination meter may be defective.

Past trouble
- Carry out diagnosis with particular emphasis on connector(s) or wiring harness in the CAN bus lines between the ABS-ECU or TCL/ASC-ECU and the combination meter, and the power supply system to the ABS-ECU or TCL/ASC-ECU.

NOTE: For a past trouble, you may not find it by the M.U.T.-III CAN bus diagnostics even if there is a failure in CAN bus lines. check the CAN bus lines. You can narrow down the possible cause of the trouble by referring to the DTC, which is set regarding the CAN communication-linked ECUs (Refer to CAN bus line Diagnostics Flow Reading and Clearing Diagnostic Trouble Codes).

TROUBLESHOOTING HINTS
- The wiring harness or connectors may have loose, corroded, or damaged terminals, or terminals pushed back in the connector
- Malfunction of ABS-ECU or TCL/ASC-ECU
- Malfunction of combination meter

DIAGNOSIS

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

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

Use scan tool MB991958 to diagnose the CAN bus lines.







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 "ON" position.
3. Diagnose the CAN bus line.
4. Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is the check result satisfactory?

YES : Go to Step 2.

NO : Repair the CAN bus lines.

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

Check that the ABS-ECU or TCL/ASC-ECU sets a diagnostic trouble code.







1. Turn the ignition switch to "ON" position.
2. Read the diagnostic trouble code.
3. Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is the DTC set?

YES : Refer to Diagnostic Trouble Code Chart [ABS] Diagnostic Trouble Code Descriptions or Diagnostic Trouble Code Chart [ASC] Diagnostic Trouble Code Descriptions.

NO : Go to Step 3.

STEP 3. Recheck for diagnostic trouble code.

Recheck if the diagnostic trouble code is set.







1. Turn the ignition switch to the "ON" position.
2. Erase the diagnostic trouble code.
3. Turn the ignition switch to the "LOCK" (OFF) position.
4. Turn the ignition switch to "ON" position.
5. Check if the diagnostic trouble code is set.
6. Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is the check result satisfactory?

YES : The procedure is complete.

NO : Replace the combination meter.