Pinpoint Test AQ: DTC U0100:87
Instrumentation, Message Center and Warning Chimes
Pinpoint Tests
Pinpoint Test AQ: DTC U0100:87
Normal Operation
- DTC U0100:87 (Lost Communication With ECM/PCM "A": Missing Message) - sets in the Instrument Panel Cluster (IPC) if data messages received from the PCM over the High Speed Controller Area Network (HS-CAN) are missing for more than 5 seconds. For a complete list of all network messages, refer to Module Communications Network Testing and Inspection.
NOTE: Once the IPC sets DTC U0100:87, multiple gauges or indicators are likely to be inoperative in the IPC. Other modules that require data from the IPC all set communication DTCs and may also exhibit system function concerns.
This pinpoint test is intended to diagnose the following:
- PCM
- IPC
PINPOINT TEST AQ: DTC U0100:87
-------------------------------------------------
AQ1 VERIFY THAT THE SCAN TOOL CAN COMMUNICATE WITH THE PCM
- Connect the scan tool.
- Check that a vehicle session can be established using the scan tool.
- Can a vehicle session be established?
Yes
GO to AQ2.
No
REFER to Module Communications Network Testing and Inspection to diagnose no communication with the PCM.
-------------------------------------------------
AQ2 CHECK THE IPC CONTINUOUS MEMORY DTCs
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: IPC Self-Test.
- Clear the DTCs. Repeat the IPC self-test.
- Is DTC U0100:87 retrieved again?
Yes
GO to AQ3.
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.
-------------------------------------------------
AQ3 RETRIEVE THE RECORDED DTCs FROM THE IPC SELF-TEST AND THE PCM KOEO SELF-TEST
- Check for recorded DTCs from the IPC self-test and the PCM Key ON Engine OFF (KOEO) self-test.
- Is DTC U3003:16 or DTC U3003:17 recorded In the IPC or DTC P0562 or P0563 recorded in the PCM?
Yes
For the IPC, GO to Pinpoint Test AY (U3003:16) or GO to Pinpoint Test AZ (U3003:17). For the PCM, REFER to Computers and Control Systems. Pinpoint Test AY: DTC U3003:16 Pinpoint Test AZ: DTC U3003:17
No
GO to AQ4.
-------------------------------------------------
AQ4 CHECK FOR DTC U0100:87 SET IN OTHER MODULES
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: Self-Test.
- Retrieve the continuous memory DTCs from all modules.
- Is DTC U0100:87 set in the Restraints Control Module (RCM)?
Yes
INSTALL a new PCM. REFER to Electronic Engine Controls Service and Repair. CLEAR the DTCs. REPEAT the self-test.
No
INSTALL a new IPC. REFER to Instrument Panel Cluster (IPC) Service and Repair. TEST the system for normal operation.
-------------------------------------------------