Pinpoint Test B: U0100:87
- Refer to Module Communications Network
for schematic and connector information.
Normal Operation and Fault Conditions
DTC Fault Trigger Conditions
DTC Description Fault Trigger Condition BCM U0100:87 Lost Communication With ECM/PCM "A": Missing Message A continuous memory DTC that sets in the BCM if powertrain data messages from the PCM over the FD-CAN through the GWM on the HS-CAN to the BCM are missing. Possible Sources
- Communication network concern
- Charging system concern
- PCM
- GWM
- BCM
- 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.
- B1 VERIFY THE DIAGNOSTIC SCAN TOOL COMMUNICATES WITH THE PCM (POWERTRAIN CONTROL MODULE)
- Ignition ON.
- Connect the diagnostic scan tool.
- Check that a vehicle session can be established.
Can a vehicle session be established?
Yes GO to B2 No REFER to: Controller Area Network (CAN) Module Communications Network - B2 RECHECK THE BCM (BODY CONTROL MODULE) CONTINUOUS MEMORY DIAGNOSTIC TROUBLE CODES (CMDTCS)
- Using a diagnostic scan tool, clear the Diagnostic Trouble Codes (DTCs).
- Wait 10 seconds.
- Using a diagnostic scan tool, check the BCM CM DTCs.
Is DTC U0100:87 retrieved again?
Yes GO to B3 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. - B3 RETRIEVE THE PCM (POWERTRAIN CONTROL MODULE) DTCS FROM THE SELF-TEST
- Using a diagnostic scan tool, perform the PCM KOEO self-test.
Are any PCM system related DTCs present?
Yes REFER to the appropriate DTC Index. No GO to B4 - B4 RETRIEVE THE BCM (BODY CONTROL MODULE) DTCS FROM THE SELF-TEST
- Using a diagnostic scan tool, perform the BCM self-test.
Are any BCM system related DTCs present?
Yes REFER to the appropriate DTC Index. No GO to B5 - B5 CHECK FOR DTC (DIAGNOSTIC TROUBLE CODE) U0100:87 SET IN OTHER MODULES
- Using a diagnostic scan tool, clear the DTCs.
- Ignition OFF.
- Ignition ON.
- Wait 10 seconds.
- Using a diagnostic scan tool, retrieve all CM DTCs.
Is DTC U0100:87 set in other modules?
Yes GO to B6 No GO to B7 - B6 CHECK FOR CORRECT PCM (POWERTRAIN CONTROL MODULE) OPERATION
- Disconnect and inspect all PCM 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 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 CHECK OASIS for any applicable service articles: TSB, GSB, SSM or FSA. If a service article exists for this concern, DISCONTINUE this test and FOLLOW the service article instructions. If no service articles address this concern, Refer to PCM GUIDED ROUTINE TESTING 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. - B7 CHECK FOR CORRECT BCM (BODY CONTROL MODULE) OPERATION
- Disconnect and inspect all BCM 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 BCM 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 CHECK OASIS for any applicable service articles: TSB, GSB, SSM or FSA. If a service article exists for this concern, DISCONTINUE this test and FOLLOW the service article instructions. If no service articles address this concern, INSTALL a new BCM. REFER to: Body Control Module (BCM) 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.