P3800high severityPowertrain
48V Mild Hybrid System General Malfunction
on 2018 Lincoln MKX 3.7L V6 · AWD
What this code means
The 48V mild hybrid system has detected a general fault preventing normal operation. The belt-driven starter-generator (BSG) and 48V battery are not functioning correctly.
Symptoms
- Mild hybrid functions disabled
- Increased fuel consumption
- No electric boost assist
- Coasting recuperation disabled
- Start-stop not functioning
- Engine feels less responsive
Common causes
- 48V battery management fault
- BSG control module error
- 48V DC-DC converter failure
- CAN communication error between modules
- 48V wiring harness damage
Diagnostic steps
- Read 48V system fault codes
- Check 48V battery voltage and SOC
- Test BSG control module communication
- Inspect 48V wiring and connectors
- Monitor 48V system during engine start and coast
Repair notes
Diagnose and replace failed 48V component. System must be de-energized before service. 48V systems can cause burns and arc flash.
Other Powertrain codes on this vehicle
P0001
Fuel Volume Regulator Control Circuit/Open
P0001
Fuel Volume Regulator Control Circuit/Open
P0002
Fuel Volume Regulator Control Circuit Range/Performance
P0002
Fuel Volume Regulator Control Circuit Range/Performance
P0003
Fuel Volume Regulator Control Circuit Low
P0003
Fuel Volume Regulator Control Circuit Low
P0004
Fuel Volume Regulator Control Circuit High
P0004
Fuel Volume Regulator Control Circuit High
P0010
Intake Camshaft Position Actuator Circuit/Open Bank 1
P0010
Intake Camshaft Position Actuator Circuit/Open Bank 1