U1434

DTC U1434: Failure information on TPMS-ECU

CAUTION:
- If DTC U1434 is set in the combination meter, diagnose the CAN main bus line.
- If DTC U1434 has been set, SWS related DTC 021 is also set. After SWS has been diagnosed, don't forget to erase DTC 021.

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 CONDITION
The combination meter communicates with the TPMS-ECU (TPMS receiver) via CAN bus line. If failure information is sent to the TPMS-ECU (TPMS receiver), DTC U1434 will be set.

TECHNICAL DESCRIPTION (COMMENT)

Current trouble
- The TPMS-ECU (TPMS receiver) or the combination meter may be defective.

Past trouble
- Carry out diagnosis with particular emphasis on connector(s) or wiring harness between the TPMS-ECU (TPMS receiver) and the combination meter. For diagnosis procedures, refer to "How to cope with past trouble" (Refer to General (Body and Chassis), How to Use Troubleshooting/Inspection Service Points).

TROUBLESHOOTING HINTS
- The wiring harness or connectors may have loose, corroded, or damaged terminals, or terminals pushed back in the connector
- Malfunction of TPMS-ECU (TPMS receiver)
- 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 (Refer to Controller Area Network (CAN), Diagnosis - Can Bus Diagnostic Chart).

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

Check if an TPMS diagnostic trouble code is set.

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 : Diagnose the TPMS by referring to Tire and Wheel, Diagnosis - Diagnostic Trouble Code Chart.

NO : Go to Step 3.

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

1. Turn the ignition switch to the "ON" position.
2. Check if a diagnostic trouble code, which relates to CAN communication-linked systems below, is set.
- ETACS-ECU
- A/C-ECU
- ECM [M/T] or PCM [A/T]
- TPMS-ECU (TPMS receiver)

3. Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is the DTC set?

YES : Go to Step 4.

NO : Go to Step 5.

STEP 4. Recheck for diagnostic trouble code.

When the TPMS-ECU (TPMS receiver) is replaced, register the encrypted code. Refer to Chassis Electrical, Encrypted Code Registration Criteria Table, and then check that the diagnostic trouble code is not reset.

1. Turn the ignition switch to "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 normally?

YES : The procedure is complete.

NO : Replace the combination meter.

STEP 5. Recheck for diagnostic trouble code.

Replace the combination meter, and then check that the diagnostic trouble code is not reset.