U1112 - FAULT CODE - OBD2

U1112 Code failures by brands

U1112 - INVALID OR MISSING DATA FOR PRIMARY ID

Description of DTC code U1112

Control Modules that connect to the Class 2 serial data circuit monitor serial data communications when the vehicle operation is stable. Exchanges of commands and operating data occur between the modules. When a controller receives a message signaling erratic performance, the controller logs a reporting module ID Code for the status of the health monitoring/live node messages.

In order to define a parameter as erratic or critical, it must not be received. Therefore, the controller uses a default value for that parameter. Once a module learns the Identification Code, it will monitor the live node message from the controller.

The DTC U1112 OBD2 setting occurs if a module does not relate an Identification Code with at least one critical parameter during a period of 5 seconds after the start of serial data communication.

Symptoms of fault code U1112

Check Engine light ON.

Causes of OBD2 U1112

The U1112 OBDII diagnostic code is stored for the following reasons:

The Control Module wires that do not communicate may be in poor condition.
The Control Module circuit may have poor connections.
The Control Module may be faulty.

Possible solutions of the DTC code U1112

Steps to troubleshoot the U1112 OBD2 fault code:

Consult the Technical Service Bulletins (TSB).
Check with a scanner if there are other DTCs stored next to the U1112, which may indicate problems with a specific module. In this case, the diagnosis should be done in the order listed.
Check for deficiencies in the wiring and connections of the non-communicating Control Module. If you discover excessive levels of corrosion or burn points, make adjustments accordingly.