If the ECM sets DTC U1180, make sure to diagnose the CAN bus line.
Before replacing the ECU, make sure that the communication circuit is operating normally.
DESCRIPTIONS OF MONITOR METHODS
There is no data from combination meter for the specified time. (Meter also detect communication error with ECM.)
MONITOR EXECUTION
Continuous
MONITOR EXECUTION CONDITIONS (Other monitor and Sensor)
Other Monitor (There is no temporary DTC stored in memory for the item monitored below)
Not applicable
Sensor (The sensor below is determined to be normal)
Not applicable
DTC SET CONDITIONS
Logic Flow Chart
Check Condition
Battery positive voltage is between 10 and 16.5 volts.
Judgment Criterion
Unable to receive combination meter signals through the CAN bus line for 4 seconds.
COMMENT
Current Trouble
Some of the possible causes are a harness or connector damage between the ECM and the combination meter on the CAN bus line, a failure in the combination meter power supply system, a failure in the combination meter, or a failure in the ECM.
Past Trouble
Proceed to troubleshoot based on a harness or connector damage on the CAN bus line between the ECM and combination meter, and a failure in the combination meter power supply system. Refer to "How to cope with past trouble" (Refer to GROUP 00, How to Use Troubleshooting/Inspection Service Points - How to Treat Past Trouble ).
note
If a malfunction occurred in the past, a failure cannot be discovered through the scan tool (M.U.T.-III) CAN bus diagnosis even if there might be a problem with the CAN bus. In this case, refer to GROUP 00, How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions . Furthermore, it is possible to narrow down the areas of the possible failures from the DTCs that are set in the ECUs, which are communicating on the CAN bus [Refer to GROUP 54C, Explanation about the Scan Tool (M.U.T.-III) CAN Bus Diagnostics ].
FAIL-SAFE AND BACKUP FUNCTION
None
OBD-II DRIVE CYCLE PATTERN
None.
TROUBLESHOOTING HINTS (The most likely causes for this code to be set are:)
CAN line harness damage or connector damage.
Combination meter failed.
ECM failed.
DIAGNOSIS
Required Special Tools:
MB992744: Vehicle Communication Interface-Lite (V.C.I.-Lite)
MB992745: V.C.I.-Lite Main Harness A
MB992747: V.C.I.-Lite USB Cable Short
MB992748: V.C.I.-Lite USB Cable Long
MB991958: Scan Tool (M.U.T.-III Sub Assembly)
MB991824: Vehicles Communication Interface (V.C.I.)
MB991827: M.U.T.-III USB Cable
MB991910: M.U.T.-III Main Harness A (Vehicles with CAN communication system)
STEP 1. Using scan tool (M.U.T.-III), diagnose CAN bus line.
caution
To prevent damage to scan tool (M.U.T.-III), always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool (M.U.T.-III).
(1) Connect scan tool (M.U.T.-III). Refer to HOW TO CONNECT THE SCAN TOOL (M.U.T.-III) .
(2) Turn the ignition switch to the "ON" position.
(3) Diagnose CAN bus line.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Is the CAN bus line normal?
Go to Step 2.
Repair the CAN bus line. Refer to GROUP 54C, Diagnosis - Can Bus Diagnostics Table . Then go to Step 4.
STEP 2. Using scan tool (M.U.T.-III), read the diagnostic trouble code (DTC).
(1) Turn the ignition switch to the "ON" position.
(2) Read the combination meter-DTC.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Is the combination meter-DTC set?
Refer to GROUP 54A, Combination Meter - Diagnostic Trouble Code Chart .
Go to Step 3.
STEP 3. Using scan tool (M.U.T.-III), read the diagnostic trouble code (DTC).
(1) Turn the ignition switch to the "ON" position.
(2) After the MFI-DTC has been deleted, read the MFI-DTC again.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Is DTC U1180 set?
Replace the ECM (Refer to Removal and Installation ). Then go to Step 4.
It can be assumed that this malfunction is intermittent of CAN bus line between ECM and combination meter. Refer to GROUP 00, How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions .
STEP 4. Using scan tool (M.U.T.-III), read the diagnostic trouble code (DTC).
(1) Turn the ignition switch to the "ON" position.
(2) After the MFI-DTC has been deleted, read the MFI-DTC again.
(3) Turn the ignition switch to the "LOCK" (OFF) position.