Hands Free Module CAN Time-Out
DTC U0197: Hands free module CAN time-out
CAUTION:
- If DTC U0197 is set, be sure to diagnose the CAN bus line.
- When replacing the ECU, always check that the communication circuit is normal.
DIAGNOSTIC FUNCTION
When the signals from hands free module cannot be received, the combination meter sets DTC U0197.
JUDGMENT CRITERIA
With the ignition switch in the ON position, system voltage between 10 - 16 volts (data from ETACS-ECU), power supply fuse (IOD fuse) is OK, or odometer value is 80.5 km (50 miles) or more, and the communications with hands free module cannot be established for 2,500 ms or more, the combination meter determines that a problem has occurred.
TROUBLESHOOTING HINTS
- The CAN bus line may be defective.
- The combination meter may be defective.
- The hands free module may be defective.
DIAGNOSIS
Required Special Tools:
- 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 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 the Scan Tool (M.U.T.-III) Reading and Clearing Diagnostic Trouble Codes."
(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 hands free module diagnostic trouble code.
Check again if the DTC is set to the hands free module.
Q. Is the DTC set?
YES Troubleshoot the hands-free cellular phone system.
NO Go to Step 3.
STEP 3. Using scan tool MB991958, read the ETACS diagnostic trouble code.
Check if the DTC U0197 is set to the ETACS-ECU.
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 to the combination meter.
(1)Erase the DTC.
(2)Turn the ignition switch from "LOCK" (OFF) position to "ON" position.
(3)Check if DTC is set.
(4)Turn the ignition switch to the "LOCK" (OFF) position.
Q. Is the DTC set?
YES Replace the hands free module.
NO The trouble can be an intermittent malfunction such as a poor connection or open circuit in the CAN bus lines between the hands free module and the combination meter How to Cope With Intermittent Malfunctions).
STEP 5. Recheck for diagnostic trouble code.
Check again if the DTC is set to the combination meter.
(1)Erase the DTC.
(2)Turn the ignition switch from "LOCK" (OFF) position to "ON" position.
(3)Check if DTC is set.
(4)Turn the ignition switch to the "LOCK" (OFF) position.
Q. Is the DTC set?
YES Replace the combination meter.
NO The trouble can be an intermittent malfunction such as a poor connection or open circuit in the CAN bus lines between the hands free module and the combination meter How to Cope With Intermittent Malfunctions).