B0120 Engine Trouble Code
What is B0120?
With B0120, you may drive for several weeks with a malfunctioning MAF sensor, but expect decreased fuel economy and eventual stalling. Shop replacement costs $240–$400 depending on vehicle. The labour is straightforward, with most cost from the part itself.
Code Information
| Code Type: | OBD-II Body (B) Trouble Code |
| System: | Body |
| Code: | B0120 |
B0120 Symptoms
Check Engine Light
Illuminated dashboard warning
Engine Stalling
Engine stops unexpectedly or misfires
Performance Issues
Reduced power or acceleration
Starting Problems
Difficulty starting the engine
B0120 Code Structure
Understanding what each digit means in the B0120 body trouble code:
| B | 0 | 1 | 2 | 0 |
|---|---|---|---|---|
| Body Code | Intake Valve Control Solenoid Circuit Low | Fuel Rail/System Pressure — Too High | Turbocharger Boost Sensor A Circuit Low | Shift Solenoid E Performance or Stuck Off |
How to Fix B0120
Diagnostic Steps:
Poor running symptoms align with MAP sensor malfunction. In some cases, a faulty MAP sensor will not trigger a code. The issue may represent separate wiring concerns requiring individual diagnosis.
Repair Solution:
VSS concerns may stem from noisy input signals caused by RFI/EMI from ignition wires, charging circuits, or aftermarket equipment. Verify VSS reads 0 mph when transmission is in Park.
Technical Notes:
B0120 DTC specifically relates to camshaft timing. When cam timing is over-retarded, the check-engine light illuminates and this code sets. Verify VCT solenoid operation and check for contamination.
B0120 Description
B0120 engine trouble code is related to Shift Solenoid E Performance or Stuck Off.
Main Cause
The primary reason for B0120 OBD-II Engine Trouble Code is: Fuel Rail/System Pressure — Too High.