Pinpoint Test AP: DTC: U0256:00
WARNING: This page is about a different car, the 2021 Ford F-150. However, it is still accessible from the selected car via links, so may be relevant.
- Refer to Wiring Diagrams MODULE COMMUNICATIONS NETWORK
for schematic and connector information.
Normal Operation and Fault Conditions
The SCMG communicate to the HVAC module using the CAN. REFER to: Front Seats - System Operation and Component Description .
DTC Fault Trigger Conditions
DTC Description Fault Trigger Condition SCMG U0256:00 Lost Communication With Front Controls Interface Module "A": No Sub Type Information Set by the SCMG whenever it has lost communication to the HVAC module for 5 seconds or longer while the SCMG input voltage is between 10 and 15.5 volts. Possible Sources
- Module communication
- SCMG
- HVAC module
- AP1 VERIFY CUSTOMER CONCERN
- Ignition ON.
- Verify there is an observable symptom present.
Is an observable symptom present?
Yes GO to AP2 No The system is operating normally at this time. The DTC may have been set due to high network traffic or intermittent fault condition. - AP2 CHECK THE COMMUNICATION NETWORK
- Ignition ON.
- Using a diagnostic scan tool, perform the network test.
Does the HVAC module pass the network test?
Yes GO to AP3 No REFER to: Front Seats - System Operation and Component Description . - AP3 RECHECK THE SCMG (DRIVER MULTI-CONTOUR SEAT MODULE) DIAGNOSTIC TROUBLE CODES (DTCS)NOTE: If new modules were installed prior to the DTC being set, the module configuration may be incorrectly set during PMI or the PMI may not have been carried out.
- Using a diagnostic scan tool, clear the Continuous Memory Diagnostic Trouble Codes (CMDTCs).
- Using a diagnostic scan tool, repeat the SCMG self-test.
Is DTC U0256:00 still present?
Yes GO to AP4 No The system is operating correctly at this time. The DTC may have been set due to high network traffic or intermittent fault condition. - AP4 CHECK FOR DTC U0256:00 IN OTHER MODULESNOTE: If new modules were installed prior to the DTC being set, the module configuration may be incorrectly set during PMI or the PMI may not have been carried out.
- Using a diagnostic scan tool, clear the Continuous Memory Diagnostic Trouble Codes (CMDTCs).
- Ignition OFF.
- Ignition ON.
- Wait 10 seconds.
- Using a diagnostic scan tool, retrieve the Continuous Memory Diagnostic Trouble Codes (CMDTCs) from all modules.
Is DTC U0256:00 set in other modules?
Yes INSTALL a new HVAC module. REFER to: Heating, Ventilation and Air Conditioning (HVAC) Control Module . No INSTALL a new SCMG. REFER to: Driver Multi-Contour Seat Module [SCMG] .