U1016 Loss of PCM Class 2 Serial Data Com

Diagnostic Trouble Code Chart:

Wiring Schematic:

CIRCUIT DESCRIPTION
The BCM receives a state of health message from the powertrain control module (PCM) through the Class II serial data link.

CONDITIONS FOR RUNNING THE DTC
The BCM does not receive a state of health message from the PCM after receiving other messages from the PCM.

CONDITIONS FOR SETTING THE DTC
The BCM does not receive a state of health message from the PCM after receiving other messages from the PCM.

ACTION TAKEN WHEN THE DTC SETS
The BCM stores DTC U1016 in memory.

CONDITIONS FOR CLEARING THE MIL/DTC
^ The DTC U1016 changes status from current to history when the BCM detects a state of health message from the PCM.
^ A history DTC will clear after 100 consecutive ignition cycles if the condition for the malfunction is no longer present.
^ Use a scan tool.

DIAGNOSTIC AIDS
^ The following conditions may cause an intermittent malfunction to occur:
- An intermittent open, short to ground or short to B+ in CKT 1037 or CKT 1049.
- Poor connections at the BCM or the PCM.
- An intermittent open in the splice pack SP205.
^ The Body Control Module (BCM) may store DTC U1016 if certain diagnostics are performed between the powertrain control module (PCM) and the Date Link Connector.

TEST DESCRIPTION
The number(s) below refer to the step number(s) on the diagnostic table.
2. This step inspects for an open in the SP205.
3. This step inspects for a short to ground in CKT 1049.
4. This step inspects for a short to B+ in CKT 1049.
5. This step inspect for an open in CKT 1049.
11. This step determines whether the malfunction is intermittent or the PCM is faulty.