Simplified Wiring System (SWS)
DTC U1100: ECM [M/T] or PCM [A/T] time-out (related to engine)
DTC U1101: ECM [M/T] or PCM [A/T] time-out (related to transaxle)
CAUTION:
- If DTC U1100 or U1101 is set in the ETACS-ECU, always diagnose the CAN main bus line.
- Whenever the ECU is replaced, ensure that the communication circuit is normal.
TROUBLE JUDGMENT
DTC U1100
- The ETACS-ECU receives engine control system-related signal from the ECM[ M/T] or PCM[ A/T]. If the ECU cannot receive the signal, DTC U1100 will be set.
DTC U1101
- The ETACS-ECU receives transaxle control system-related signal from the ECM[ M/T] or PCM[ A/T]. If transaxle control system-related signal cannot be received, DTC U1101 will be set.
TECHNICAL DESCRIPTION (COMMENT)
Current trouble
- Connector(s) or wiring harness in the CAN bus lines between the ECM[ M/T] or PCM[ A/T] and the ETACS-ECU, the power supply system to the ECM[ M/T] or PCM[ A/T], the ECM[ M/T] or PCM[ A/T] itself, or the ETACS-ECU may be defective.
Past trouble
- If DTC U1100 or U1101 is stored as a past trouble, carry out diagnosis with particular emphasis on wiring and connector(s) in the CAN bus line between the ETACS-ECU and the ECM[ M/T] or PCM[ A/T], and the power supply system to the ECM[ M/T] or PCM[ A/T]. For diagnosis procedures, refer to "How to cope with past trouble" How to Treat Past Trouble ).
NOTE:
You cannot find a past trouble, by the M.U.T.-III CAN bus diagnostics even if there is a failure in CAN bus lines. In this case, refer to How to Cope with Intermittent Malfunction How to Cope With Intermittent Malfunctions and 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 CAN Bus Line Diagnostics Flow ).
TROUBLESHOOTING HINTS
- The wiring harness or connectors may have loose, corroded, or damaged terminals, or terminals pushed back in the connector.
- The ECM[ M/T] or PCM[ A/T] may be defective.
- The ETACS-ECU may be defective.
DIAGNOSIS
Required Special Tools:
- MB991223: Harness Set
- MB992006: Extra Fine Probe
- 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.
(1)
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.
Connect scan tool MB991958. Refer to "How to connect SWS monitor How to Connect SWS Monitor."
(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 CAN Bus Diagnostics Chart).
STEP 2. Using scan tool MB991958, read the ECM [M/T] or PCM [A/T] diagnostic trouble code.
Check whether engine and transaxle DTCs are set or not.
(1)Turn the ignition switch to the "ON" position.
(2)Check for engine and transaxle DTCs.
(3)Turn the ignition switch to the "LOCK" (OFF) position.
Q. Is the DTC set?
YES Diagnose the ECM [M/T] or PCM [A/T] Multiport Fuel Injection (MFI) [2.4 L engine], Multiport Fuel Injection (MFI) [3.8 L engine] or Diagnosis Automatic Transmission [A/T]).
NO Go to Step 3.
STEP 3. Using scan tool MB991958, read the for any diagnostic trouble code.
Check if a DTC, which relates to CAN communication-linked systems below, is set.
- Combination meter (DTC U1100 or U1101)
DTC indicating a time-out error related to the engine or automatic transaxle control system
- A/C (DTC U1100)
DTC indicating a time-out error related to the engine or automatic transaxle control system
(1)Turn the ignition switch to the "ON" position.
(2)Check for DTC U1100 or U1101 related to the relevant system.
(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.
Check again if the DTC is set.
(1)Erase the DTC.
(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 the DTC set?
YES Replace the ECM [M/T] or PCM [A/T]. On completion, verify that the DTC is not reset.
NO A poor connection, open circuit or other intermittent malfunction is present in the CAN bus lines between the ECM [M/T] or PCM [A/T] and the ETACS-ECU How to Cope With Intermittent Malfunctions).
STEP 5. Recheck for diagnostic trouble code.
Check again if the DTC is set.
(1)Erase the DTC.
(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 the DTC set?
YES Replace the ETACS-ECU. When the ETACS-ECU is replaced, register the encrypted code. Encrypted Code Registration Criteria Table. On completion, verify that the DTC is not reset.
NO A poor connection, open circuit or other intermittent malfunction is present in the CAN bus lines between the ECM [M/T] or PCM [A/T] and the ETACS-ECU How to Cope With Intermittent Malfunctions).