[Previous][Next]
DTC U15A0 ACC/FCM ECU CAN timeout
 
 
caution
  • If DTC U15A0 is set in the ETACS-ECU, always diagnose the CAN bus line.
  • Before replacing the ECU, ensure that the power supply circuit, the ground circuit and the communication circuit are normal.
 
 
DIAGNOSTIC FUNCTION
If the signal from ACC/FCM-ECU cannot be received, the ETACS-ECU sets DTC U15A0.
 
 
TROUBLE JUDGMENT
After the following statuses continue to be true for 5 seconds, if the communication with the ACC/FCM-ECU cannot be established for 2,500 ms or more, the ETACS-ECU determines that a problem has occurred.
  • No abnormality is present to the network.
  • Ignition switch is in the "ON" position.
  • No abnormality is present to the power supply fuse (IOD fuse), or the odometer value is at 80.5 km (50.0 miles) or more.
  • ETACS-ECU system voltage is at 10-16 volts.
 
 
TROUBLESHOOTING HINTS
  • The ACC/FCM-ECU may be defective
  • The ETACS-ECU may be defective
  • The CAN bus line may be defective
 
 
DIAGNOSIS
STEP 1. Using scan tool (M.U.T.-IIISE), diagnose the CAN bus line.
(1)
cautionTo prevent damage to scan tool (M.U.T.-IIISE), always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool (M.U.T.-IIISE).
Connect scan tool (M.U.T.-IIISE). Refer to "How to connect the Scan Tool (M.U.T.-IIISE) ."
(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.
Is the CAN bus line found to be normal?
Go to Step 2.
Repair the CAN bus line (Refer to GROUP 54C - Troubleshooting ).
 
STEP 2. Using scan tool (M.U.T.-IIISE), read the other system DTC.
Check if DTC is set in the ACC/FCM-ECU.
Is the DTC set?
Troubleshoot the ACC. Refer to GROUP 17 - Diagnostic trouble code chart .
Go to Step 3.
 
STEP 3. Using scan tool (M.U.T.-IIISE), read the other system DTC.
Check if DTC U15A0 is set in the ASC-ECU.
Is the DTC set?
Go to Step 4.
Go to Step 5.
 
STEP 4. Using scan tool (M.U.T.-IIISE), read the DTC again.
Check again if the DTC is set in the ETACS-ECU.
(1) Erase the DTC.
(2) Turn the ignition switch from "LOCK" (OFF) position to "ON" position.
(3) Check if DTC is set.
Is the DTC set?
Replace the ACC/FCM-ECU.
The trouble can be an intermittent malfunction such as a poor connection or open circuit in the CAN bus lines between the ACC/FCM-ECU and the ETACS-ECU (GROUP 00 - How to use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction ).
 
STEP 5. Using scan tool (M.U.T.-IIISE), read the DTC again.
Check again if the DTC is set in the ETACS-ECU.
(1) Erase the DTC.
(2) Turn the ignition switch from "LOCK" (OFF) position to "ON" position.
(3) Check if DTC is set.
Is the DTC set?
Replace the ETACS-ECU.
The trouble can be an intermittent malfunction such as a poor connection or open circuit in the CAN bus lines between the ACC/FCM-ECU and the ETACS-ECU (GROUP 00 - How to use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction ).