B3549 Engine Trouble Code
What is B3549?
When B3549 code appears, first check your gas cap. Pull over safely, ensure it is tight, and inspect for cracks. A loose or damaged gas cap affects fuel-system pressure and emissions. A replacement cap costs about $3–$10. This simple fix can resolve the code and improve fuel economy.
Code Information
| Code Type: | OBD-II Body (B) Trouble Code |
| System: | Body |
| Code: | B3549 |
B3549 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
B3549 Code Structure
Understanding what each digit means in the B3549 body trouble code:
| B | 3 | 5 | 4 | 9 |
|---|---|---|---|---|
| Body Code | Ignition System Or Misfire | Fuel Composition Sensor Circuit Malfunction | Injection Pump Fuel Metering Control 'B' High | Reverse Input Circuit |
How to Fix B3549
Diagnostic Steps:
Oxygen sensors measure exhaust gas oxygen content to optimise air-fuel ratio. This optimisation improves fuel economy and reduces emissions. Sensors degrade over time and require periodic replacement.
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:
B3549 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.
B3549 Description
B3549 engine trouble code is related to Reverse Input Circuit.
Main Cause
The primary reason for B3549 OBD-II Engine Trouble Code is: Fuel Composition Sensor Circuit Malfunction.