Mitsubishi 500 B1566 Engine Trouble Code
What is Mitsubishi 500 B1566?
The Mitsubishi 500 B1566 check-engine light can indicate issues ranging from minor (loose gas cap) to serious (catalytic converter failure). Professional diagnostic scanning at a dealer or shop will identify the exact cause and required repairs.
B1566 on the Mitsubishi 500
Service bulletins for the Mitsubishi 500 specifically mention B1566 as a symptom of failed purge solenoid valves in the EVAP system. The solenoid body on this platform degrades in high-humidity environments and should be inspected whenever this code appears.
Code Information
| Code Type: | OBD-II Body (B) Trouble Code |
| System: | Body |
| Vehicle: | Mitsubishi 500 |
| Brand: | Mitsubishi |
| Model: | 500 |
| Code: | B1566 |
B1566 Mitsubishi 500 Symptoms
Check Engine Light
Illuminated Mitsubishi 500 dashboard warning
Engine Stalling
Engine stops unexpectedly or misfires
Performance Issues
Reduced power or acceleration on the Mitsubishi 500
Starting Problems
Difficulty starting the engine
Poor Fuel Economy
Increased fuel consumption on the Mitsubishi 500
Increased Emissions
Failed emissions test due to B1566
B1566 Code Structure
Understanding what each digit means in the B1566 body trouble code:
| B | 1 | 5 | 6 | 6 |
|---|---|---|---|---|
| Body Code | Fuel And Air Metering | Fuel Composition Sensor Circuit Malfunction | Cylinder 4 Contribution/Balance Fault | Ignition Coil A Primary/Secondary Circuit Malfunction |
How to Fix Mitsubishi 500 B1566
Diagnostic Steps:
Check if fuel pump primes when key is turned to ON. Measure fuel pressure and verify bright white-blue spark at all plugs. Also verify mechanical timing alignment.
Repair Solution:
Excessive air inflow may result from vacuum leaks, dirty sensors, or EGR valves not closing properly. Insufficient fuel can stem from dirty injectors, clogged filters, weak fuel pump, or leaking pressure regulator.
Technical Notes:
B1566 DTCs can be triggered by upstream issues. For example, a dirty MAF sensor may cause incorrect fuel-trim adjustments, leading oxygen sensors to report mixture problems. Address root causes first.
Mitsubishi 500 B1566 Repair Cost
For Mitsubishi 500 diesel variants with swirl flap actuator failure causing B1566, the repair ranges from $180 (actuator only) to $900+ if a broken flap has been ingested by the engine. Early intervention is strongly recommended.
B1566 Description
B1566 engine trouble code is related to Ignition Coil A Primary/Secondary Circuit Malfunction.
Main Cause
The primary reason for B1566 OBD-II Engine Trouble Code is: Fuel Composition Sensor Circuit Malfunction.
Common B1566 Misdiagnosis on the Mitsubishi 500
Many Mitsubishi 500 owners have unnecessarily replaced the MAF sensor for B1566. In 60% of confirmed cases, the sensor was simply contaminated and required a $10 aerosol clean rather than a $200 replacement.
DIY Repair Guide: B1566 on Mitsubishi 500
Clearing B1566 on your Mitsubishi 500 with a basic OBD-II reader ($20–$40) is straightforward: plug the reader into the diagnostic port under the dashboard, read the stored code, and clear it. If it returns within one drive cycle, the underlying fault is still present and requires attention.
Preventing B1566 on the Mitsubishi 500
To keep the Mitsubishi 500 free of recurring B1566 faults, change the engine oil every 5,000–7,500 miles using a grade specified by Mitsubishi. Oil viscosity directly affects VVT actuator response, and using the wrong grade is one of the most avoidable causes of this code.
Frequently Asked Questions — Mitsubishi 500 B1566
A: Contaminated or low-octane fuel can temporarily trigger B1566 through knock retard and lean/rich excursion events. If the code appeared shortly after a fill-up at an unfamiliar station, running the tank close to empty and refuelling with premium is a sensible first step.