Ford-specific code — factory diagnostic data| DTC Data Sheet | |
| Code | U0401-00 |
| Vehicle | 2011 Ford F-150 |
| Module | OCCUPANT CLASSIFICATION SYSTEM MODULE (OCSM) |
| Fault type | Circuit |
| Official meaning | Invalid Data Received From ECM/PCM "a": No Sub Type Information |
Definition source: Ford factory description. Diagnostic guidance is based on factory-defined fault logic for this code.
Decode any Ford F-150 VIN — free recalls, specs & safety ratings — free VIN decoder with NHTSA data
Looking for the cross-vehicle definition? Read the generic U0401 article for the SAE-defined fault logic that applies to all manufacturers.
U0401-00 Quick Answer
U0401-00 on a 2011 F-150: Invalid Data Received From ECM/PCM "a": No Sub Type Information. Ford’s factory diagnostic guidance for this code: U0401:00 sets in a module that is reporting a communication fault from another module on the data bus. The module that reports the fault is not the problem module. Do not install a new OCSM as part of repair for DTC U0401:00. CARRY OUT PCM Self Test. REPAIR any speed-related DTC…
What Does U0401-00 Mean on a 2011 F-150?
The 2011 Ford F-150 uses the OCCUPANT CLASSIFICATION SYSTEM MODULE (OCSM) to monitor and diagnose this circuit. U0401-00 is set when the module detects invalid data received from ecm/pcm "a": no sub type information. The official meaning per the 2011 F-150 service information is exactly: Invalid Data Received From ECM/PCM "A": No Sub Type Information.
Symptoms
- Check engine light or system warning indicator on the instrument cluster
- Reduced functionality of the affected occupant classification system module (ocsm) system
- Possible co-codes from connected modules on the 2011 F-150 CAN bus (HS-CAN/MS-CAN)
Common Causes
- Fault in the named component, sensor, or actuator circuit
- Open or shorted wiring in the affected circuit
- Connector corrosion or backed-out terminal
- Loss of supply voltage or ground at the affected device
- Module internal fault (rare — verify wiring and supplies first)
Ford-Recommended Diagnostic Action
Per the 2011 Ford F-150 service information for U0401-00:
U0401:00 sets in a module that is reporting a communication fault from another module on the data bus. The module that reports the fault is not the problem module. Do not install a new OCSM as part of repair for DTC U0401:00. CARRY OUT PCM Self Test. REPAIR any speed-related DTCs. REFER to DTC CHART in INTRODUCTION – GASOLINE MODELS .
Pinpoint test references above are Ford F-150 service-manual chart numbers. Refer to the corresponding chart in the Ford 2011 F-150 Workshop Manual for step-by-step diagnostic procedures.
Diagnostic Approach
For U0401-00 on the 2011 Ford F-150 you’ll need a scan tool that reads the OCSM on the 2011 F-150 — required for OCS calibration — plus a digital multimeter.
- Verify the code is current rather than just stored history. Use the scan tool’s self-test on the OCCUPANT CLASSIFICATION SYSTEM MODULE (OCSM).
- Read freeze-frame data and any related codes. Modules sharing CAN bus segments often log overlapping faults.
- Inspect the connector at the device named in the code description. Wiggle-test the connector while monitoring live data to expose intermittent faults.
- Measure supply voltage and ground integrity at the affected device with the engine running.
- Follow the Ford-recommended action above — including any pinpoint-test reference — for procedure-level diagnosis.
- If supplies are clean and the connector is sound, isolate the device with a known-good substitute. Re-clear the code and verify it does not return on a road test.
Possible Fixes
- Replace the failed device or sensor identified during diagnosis
- Repair open or shorted wiring
- Connector pin-tension or pigtail repair
- Module replacement and PMI (Programmable Module Installation) if the module itself is faulty
Can I Still Drive With U0401-00?
Drivability impact depends on the affected subsystem. OCCUPANT CLASSIFICATION SYSTEM MODULE (OCSM) faults that affect a primary safety system (brakes, restraints, steering) should be repaired before further driving. Comfort or convenience faults can usually be deferred briefly without immediate safety risk.
FAQ
Will U0401-00 clear itself on a Ford F-150?
If the underlying fault was a momentary glitch — for example a brief connector dropout or a one-time low-voltage event — the U0401-00 may clear after a few drive cycles. Persistent root causes (failed device, broken wire, corroded terminal) will keep the fault active until the affected component is repaired on the Ford F-150.
Can I drive my Ford F-150 with U0401-00 active?
It depends which subsystem is affected. If the U0401-00 is in a primary safety system (brakes, restraints, steering, air suspension), the Ford F-150 should be driven only to a workshop. Comfort, lighting, and audio faults are lower priority but still worth addressing — the Ford F-150’s CAN architecture means a single unresolved code can mask others.
How much does it cost to fix U0401-00 on a Ford F-150?
Repair cost depends on the named device. On the Ford F-150, simple connector or wiring repairs typically run $80-200 in shop labour. Sensor replacements run $120-450 including parts and diagnostic time. Module replacement (when the affected control module itself has failed) is the most expensive path at $400-1,200 depending on whether the new module needs programming. Get a written estimate that breaks out diagnosis time, parts, and any required PMI / programming charge.
What does the official Ford F-150 service definition say about U0401-00?
Per the factory service information, U0401-00 is defined as: Invalid Data Received From ECM/PCM "a": No Sub Type Information. The diagnostic procedure is in the Ford F-150 service-manual chapter for the affected module.