U1016

Circuit Description
The Class 2 serial data line allows all of the modules on the line to transmit information to each other as needed. Each module is assigned an ID. All of the information sent out on the line is assigned a priority by which the information is received. When the ignition switch is turned to the ON position each module begins to send and receive information. Each module on the Class 2 serial data line knows the information that is needed to send out and the information that the module should be receiving. What the modules do not know is which module is supposed to send the original module the information. This information is only learned after the module has received the necessary information with the ID of the module that sent the information. This information is then remembered until the ignition switch is turned to the OFF position. If the EBCM loses communication with the Powertrain Control Module (PCM), then DTC U1016 will be set by the EBCM.

Conditions for Setting the DTC
The DTC may be set any time the ignition is in the ON position and the PCM does not communicate with the EBCM for 5 seconds.

Action Taken When the DTC Sets
- The ABS remains enabled.
- The CAR ICON (DTCS indicator) turns ON.

Conditions for Clearing the DTC
- The condition for the DTC is no longer present and the scan tool Clear DTC function is used.
- Fifty ignition cycles have passed with no DTCs detected.

Diagnostic Aids
- Perform a thorough inspection of the wiring and connectors. Failure to carefully and fully inspect wiring and connectors may result in misdiagnosis, causing unnecessary part replacement with reappearance of the malfunction.
- An intermittent problem may be caused by the following conditions:
- Poor electrical connection
- Worn wire insulation
- A wire that is broken inside the wire insulation
- If an intermittent malfunction exists, refer to Testing for Electrical Intermittents in Overall Vehicle Information / Testing and Inspection.

Step 1:

Steps 2 - 6:

Steps 7 - 8:

Test Description