DTC U1056: Loss Of Communication With RTD: Testing

If IPC diagnostic system check was performed, go to next step. If IPC diagnostic system check was not performed, go to procedures in IPC DIAGNOSTIC SYSTEM CHECK .
Turn ignition off. Connect scan tool. Turn ignition on. Using scan tool, attempt to establish communication with RTD system. If communication can be established, go to next step. If communication cannot be established, see SUSPENSION - ELECTRONIC REAL TIME DAMPING article in SUSPENSION section.
Using scan tool, select IPC DTCs function. Check for DTC U1255. If DTC U1255 exists, go to DTC U1255: SERIAL DATA LINE MALFUNCTION . If DTC U1255 does not exist, go to next step.
Check serial data line for following intermittent conditions:
- An open in serial data line between IPC and RTD system.
- Short to ground.
- Short to voltage.
- Check star connector No. 1 (ensure bus bar is properly inserted).
- Loose or damaged terminals.
If no problem is found, go to next step. If problem is found, repair as necessary. Go to step 6).
Turn ignition off. Reinstall all components and connectors. Turn ignition on. Clear DTCs. Check for DTCs. If DTC U1056 is current, see SUSPENSION - ELECTRONIC REAL TIME DAMPING article in SUSPENSION section. If DTC U1056 is not current, system is operating properly.
Turn ignition off. Reinstall all components and reconnect all connectors. Turn ignition on. Clear DTCs. Perform procedures in IPC DIAGNOSTIC SYSTEM CHECK .