DTC U0122: Acoustic Vehicle Alerting Control Unit Lost Communication With VSA Modulator-Control Unit (2015 2017)
| DTC Description | Confirmed DTC | Pending DTC |
|---|---|---|
| U0122: Acoustic vehicle alerting control unit lost communication with VSA modulator-control unit |
DTC (Acoustic Vehicle Alerting Control Unit)
NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information - Refer to: HOW TO TROUBLESHOOT THE FUEL AND EMISSIONS SYSTEMS (2014 2015), or HOW TO TROUBLESHOOT THE GEAR UNIT CONTROL SYSTEM, or HOW TO TROUBLESHOOT THE FUEL AND EMISSIONS SYSTEMS (2017) .
- CAN gateway system DTC check
- 1. Check for CAN gateway system DTCs with the HDS.
DTC Description DTC U0029-00: CAN Gateway F-CAN ch A Bus Off U0047-00: CAN Gateway F-CAN ch B Bus Off U0056-00: CAN Gateway F-CAN ch C Bus Off U3000-49: CAN Gateway Internal Failure DTC (CAN GATEWAY)
Is DTC U0029-00, U0047-00, U0056-00, and/or U3000-49 indicated?
YES
Go to the troubleshooting for CAN gateway system DTC(s) - Refer to: COMMUNICATION SYSTEMS DTC TROUBLESHOOTING INDEX (2014), or COMMUNICATION SYSTEMS DTC TROUBLESHOOTING INDEX (2015), or COMMUNICATION SYSTEMS DTC TROUBLESHOOTING INDEX (2017) .
NO
Go to step 2.
- F-CAN circuit communication check
- 1. Select the FUNCTION TEST in the CAN gateway with the HDS, then select the F-CAN Bus Connected Unit Check.
Which result is indicated?
Acoustic vehicle alerting control unit (Bus B) is Not Available
Go to step 3.
VSA modulator-control unit (Bus B) is Not Available
Go to step 4.
VSA modulator-control unit (Bus C) is Not Available
Go to step 5.
Acoustic vehicle alerting control unit and VSA modulator-control unit are Detect
Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the acoustic vehicle alerting control unit, the CAN gateway, and the VSA modulator-control unit.
- Open wire check (F-CAN B lines)
- 1. Turn the vehicle to the OFF (LOCK) mode.
- 2. Disconnect the following connectors.
CAN gateway 24P connector - Refer to: CAN GATEWAY REMOVAL AND INSTALLATION (2014 2015), or CAN GATEWAY REMOVAL AND INSTALLATION (2017) ACOUSTIC VEHICLE ALERTING CONTROL UNIT 12P CONNECTOR - 3. Check for continuity between test points 1 and 2 respectively.
Test condition Vehicle OFF (LOCK) mode CAN gateway 24P connector: disconnected
Acoustic vehicle alerting control unit 12P connector: disconnected
Test circuit F-CAN B_H Test point 1 CAN gateway 24P connector No. 11 (GRN) Test point 2 Acoustic vehicle alerting control unit 12P connector No. 5 (GRN) Test circuit F-CAN B_L Test point 1 CAN gateway 24P connector No. 10 (LT GRN) Test point 2 Acoustic vehicle alerting control unit 12P connector No. 6 (LT GRN) Is there continuity?
YES
The F-CAN B_H and F-CAN B_L wires are OK. Check for poor connections or loose terminals at the CAN gateway and the acoustic vehicle alerting control unit. SUBSTITUTE A KNOWN-GOOD ACOUSTIC VEHICLE ALERTING CONTROL UNIT , then recheck. If the DTC U0122 goes away and the acoustic vehicle alerting control unit was substituted, REPLACE THE ORIGNAL ACOUSTIC VEHICLE ALERTING CONTROL UNIT .
NO
Repair an open in F-CAN B_H or F-CAN B_L wire between the CAN gateway and the acoustic vehicle alerting control unit.
- Open wire check (F-CAN B lines)
- 1. Turn the vehicle to the OFF (LOCK) mode.
- 2. Disconnect the following connectors.
CAN gateway 24P connector - Refer to: CAN GATEWAY REMOVAL AND INSTALLATION (2014 2015), or CAN GATEWAY REMOVAL AND INSTALLATION (2017) or VSA MODULATOR-CONTROL UNIT 21P CONNECTOR - 3. Check for continuity between test points 1 and 2 respectively.
Test condition Vehicle OFF (LOCK) mode CAN gateway 24P connector: disconnected
VSA modulator-control unit 21P connector: disconnected
Test circuit F-CAN B_H Test point 1 CAN gateway 24P connector No. 11 (GRN) Test point 2 VSA modulator-control unit 21P connector No. 8 (LT BLU) Test circuit F-CAN B_L Test point 1 CAN gateway 24P connector No. 10 (LT GRN) Test point 2 VSA modulator-control unit 21P connector No. 15 (LT GRN) Is there continuity?
YES
The F-CAN B_H and F-CAN B_L wires are OK. Check for poor connections or loose terminals at the CAN gateway and the VSA modulator-control unit. UPDATE THE VSA MODULATOR-CONTROL UNIT if it does not have the latest software, then recheck. If the DTC U0122 goes away and the VSA modulator-control unit was updated, troubleshooting is complete. If the DTC U0122 goes away and the VSA modulator-control unit was substituted, REPLACE THE ORIGINAL VSA MODULATOR-CONTROL UNIT .
NO
Repair an open in F-CAN B_H or F-CAN B_L wire between the CAN gateway and the VSA modulator-control unit.
- Open wire check (F-CAN C lines)
- 1. Turn the vehicle to the OFF (LOCK) mode.
- 2. Disconnect the following connectors.
CAN gateway 24P connector - Refer to: CAN GATEWAY REMOVAL AND INSTALLATION (2014 2015), or CAN GATEWAY REMOVAL AND INSTALLATION (2017) or VSA MODULATOR-CONTROL UNIT 21P CONNECTOR - 3. Check for continuity between test points 1 and 2 respectively.
Test condition Vehicle OFF (LOCK) mode CAN gateway 24P connector: disconnected
VSA modulator-control unit 21P connector: disconnected
Test circuit F-CAN C_H Test point 1 CAN gateway 24P connector No. 9 (TAN) Test point 2 VSA modulator-control unit 21P connector No. 9 (ORN) Test circuit F-CAN C_L Test point 1 CAN gateway 24P connector No. 8 (PUR) Test point 2 VSA modulator-control unit 21P connector No. 16 (PUR) Is there continuity?
YES
The F-CAN C_H and F-CAN C_L wires are OK. Check for poor connections or loose terminals at the CAN gateway and the VSA modulator-control unit. UPDATE THE VSA MODULATOR-CONTROL UNIT if it does not have the latest software, then recheck. If the DTC U0122 goes away and the VSA modulator-control unit was updated, troubleshooting is complete. If the DTC U0122 the goes away and the VSA modulator-control unit was substituted, REPLACE THE ORIGINAL VSA MODULATOR-CONTROL UNIT .
NO
Repair an open in F-CAN C_H or F-CAN C_L wire between the CAN gateway and the VSA modulator-control unit.