OBD2 Code U1248: Invalid Time/Date Data on SCP Bus
The U1248 code indicates that a control module has detected invalid or missing time and date data on the SCP (Standard Corporate Protocol) J1850 communication bus. This Ford-developed protocol uses variable pulse width (VPW) signaling at 41.6 kbps. The fault occurs when a module (such as the instrument cluster, audio module, or body control module) expects a time/date message from the master module (typically the cluster or GEM/SJB) but the message is missing, corrupted, or contains out-of-range values. This data is used for functions like the dashboard clock, system event timestamps, and diagnostic logs.
1. Commonly Affected Makes
2. Most Common Causes
- Faulty master module generating time/date data (instrument cluster or GEM/SJB)
- Open or short circuit in the SCP J1850 bus wiring (pins 2 and 10 of the DLC)
- SCP bus termination resistance out of specification (typically 120 ohms)
- Receiving module unable to properly interpret SCP messages
- Electromagnetic interference affecting VPW signal integrity
- Disconnected or discharged battery causing loss of time/date configuration data
- Corrupted or incompatible module software
3. Symptoms You Will Notice
- Incorrect or blank clock display on the dashboard
- Missing or inaccurate timestamps in system event logs
- Other modules may set related communication fault codes
4. Step-by-Step Diagnosis
Scan all modules for related codes and check time/date data from master module
Inspect SCP bus wiring between DLC pins 2 and 10 for damage or corrosion
Measure bus termination resistance at the DLC; should be approximately 60 ohms (two 120 ohm resistors in parallel)
Check battery voltage and history of disconnection; reset time/date and clear codes
If wiring and termination are good, suspect a faulty master module or software issue
5. Frequently Asked Questions
Is it safe to drive?▼
Yes, the vehicle is generally safe to drive. The fault primarily affects non-critical functions like the clock and event logging. However, it may indicate an underlying communication issue that could affect other systems over time.
How much does it cost to fix?▼
Diagnosis typically costs $100-$150. If the master module needs replacement, expect $300-$800 including parts and labor. Simple wiring repairs may be $100-$200.