B3516 Engine Trouble Code
What is B3516?
B3516 indicates potential catalytic converter failure. If completely failed, your vehicle may not run properly and fuel economy will suffer significantly. Average replacement cost is $2,000–$2,140. This repair requires professional service and should not be delayed.
Code Information
| Code Type: | OBD-II Body (B) Trouble Code |
| System: | Body |
| Code: | B3516 |
B3516 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
B3516 Code Structure
Understanding what each digit means in the B3516 body trouble code:
| B | 3 | 5 | 1 | 6 |
|---|---|---|---|---|
| Body Code | Ignition System Or Misfire | Fuel Composition Sensor Circuit Malfunction | Engine Shutoff Solenoid Malfunction | Ignition Coil A Primary/Secondary Circuit Malfunction |
How to Fix B3516
Diagnostic Steps:
The catalytic converter has oxygen sensors before and after it. When warm and in closed-loop mode, the upstream O2 sensor reading should fluctuate, while downstream should remain steady.
Repair Solution:
Disconnected, dirty, or fouled spark plugs commonly prevent proper engine operation. Replace spark plugs every season or 25 hours. Verify proper spark plug gap. If plugs are good, check ignition components: spark plug wires, coils, and ignition module.
Technical Notes:
Parts or components should not be replaced based solely on B3516 DTC. Consult your vehicle service manual for proper diagnostic procedures, possible causes, and required testing before replacement.
B3516 Description
B3516 engine trouble code is related to Ignition Coil A Primary/Secondary Circuit Malfunction.
Main Cause
The primary reason for B3516 OBD-II Engine Trouble Code is: Fuel Composition Sensor Circuit Malfunction.