If DTC U1190 is set in the BSW-ECU (master), 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.
OPERATION
The BSW-ECU (master) communicates with the ETACS-ECU via the gateway-ECU and CAN bus lines.
DIAGNOSTIC FUNCTION AND JUDGMENT CRITERIA
When the BSW-ECU (master) cannot receive any fault detect signal from the ETACS-ECU within 5 seconds after the ignition switch is turned on, the ECU sets DTC U1190.
TROUBLESHOOTING HINTS
The ETACS-ECU may be defective
The BSW-ECU (master) may be defective
DIAGNOSIS
STEP 1. Using scan tool (M.U.T.-III) CAN bus diagnostics
Use the scan tool (M.U.T.-III) to diagnose the CAN bus lines.
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).
Connect scan tool (M.U.T.-III). Refer to "How to connect the Scan Tool (M.U.T.-III) ."
Is the check result normal?
Go to Step 2.
Repair the CAN bus line (Refer to GROUP 54C - Troubleshooting ).
STEP 2. Using scan tool (M.U.T.-III) other system DTC
Check if DTC U1190 is set in the gateway-ECU.
Is the DTC set?
Troubleshoot the gateway-ECU (Refer to GROUP 54C - Troubleshoot <GATEWAY> - Diagnostic trouble Code Chart ).
Go to Step 3.
STEP 3. Check whether the DTC is set again.
Check again if the DTC is set in the BSW-ECU (master).
(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 BSW-ECU (master).
Intermittent malfunction is suspected (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction ).