Pinpoint Test O: U0300

Normal Operation and Fault Conditions

If the PCM does not receive messages from other modules within a certain time frame the PCM sets a DTC for lost communication.

DTC Fault Trigger Conditions

DTC	Description	Fault Trigger Condition
PCM U0300:00	Internal Control Module Software Incompatibility: No Sub Type Information	This DTC sets due to an internal fault with the PCM.

Possible Sources

Communications network concern
BCM module
GWM
PCM

O1 VERIFY THE CUSTOMER CONCERN

Ignition ON.

Verify there is an observable symptom present.

Is an observable symptom present?

Yes

GO to O2

No	The system is operating normally at this time. The DTC may have been set due to high network traffic or an intermittent fault condition.

O2 CHECK THE COMMUNICATION NETWORK
- Using a diagnostic scan tool, perform a network test.
Did the module pass the network test?

Yes GO to O3

No REFER to: Controller Area Network (CAN) Module Communications Network

O3 CHECK THE GWM DIAGNOSTIC TROUBLE CODES (DTCS)
- Using a diagnostic scan tool, retrieve the GWMDTC s.
Are any DTC s recorded?

Yes REFER to: Controller Area Network (CAN) Module Communications Network

No GO to O4

O4 PERFORM THE PCM SELF-TEST
- Using a diagnostic scan tool, perform the PCM self-test.
Are any non-network DTC s present?

Yes REFER to Diagnostic Trouble Code (DTC) Chart .

No GO to O5

O5 RECHECK THE PCM DIAGNOSTIC TROUBLE CODES (DTCS)

NOTE: If new modules were installed prior to the DTC being set, the module configuration may be incorrectly set during the PMI, or the PMI may not have been carried out.

Using a diagnostic scan tool, clear the DTC s.

Wait 10 seconds.

Repeat the PCM self-test.

Is DTC U0300 still present?

Yes

GO to O6

No	The system is operating correctly at this time. The DTC may have been set due to high network traffic or an intermittent fault condition.

O6 CHECK FOR OTHER CAUSES OF COMMUNICATION NETWORK CONCERN

NOTE: If new modules were installed prior to the DTC being set, the module configuration can be incorrectly set during the PMI or the PMI may not have been carried out.

CHECK the vehicle service history for recent service actions related to the ABS, BCM, GWM, IPC MODULE, or PCM. If recent service history is found:
- verify correct replacement module was installed
  - HVBOM may be used to verify correct part fit
- verify the configuration of replacement module was correct
  - re-configure module using as-built data if prior configuration is suspect
- verify the module was not obtained from a like vehicle and installed into customer vehicle
  - return the swapped module to source vehicle and obtain new replacement module

Operate the system and determine if the observable symptom is still present.

Is the observable symptom still present?

Yes

GO to O7

No	The system is operating correctly at this time. The concern may have been due to incorrect parts replacement procedures or incorrect module configuration.

O7 CHECK FOR CORRECT PCM OPERATION

Ignition OFF.

Disconnect and inspect the PCM control module connectors.

Repair:
- corrosion
  - install new connector or terminals
  - clean module pins
- damaged or bent pins
  - install new terminals/pins
- pushed-out pins
  - install new pins as necessary

Reconnect the PCM control module connectors. Make sure they seat and latch correctly.

Operate the system and determine if the concern is still present.

Is the concern still present?

Yes	INSTALL a new PCM. Refer to Powertrain Control Module (PCM) .

No	The system is operating correctly at this time. The concern may have been caused by module connections. ADDRESS the root cause of any connector or pin issues.