Mitsubishi A10 B1805 Engine Trouble Code
What is Mitsubishi A10 B1805?
Mitsubishi A10 B1805 code can indicate a faulty oxygen sensor, which may eventually damage the catalytic converter (repair cost: $2,000–$2,200). Professional diagnosis costs around $200–$210. Oxygen sensors are often straightforward to replace — check your owner's manual for location and instructions. This issue should be addressed promptly to prevent further damage.
B1805 on the Mitsubishi A10
On high-mileage Mitsubishi A10 examples, B1805 is often the first sign of a failing fuel pressure regulator. Residual fuel pressure bleeds off overnight, causing lean-start conditions that the ECU registers as a fault at the next cold start.
Code Information
| Code Type: | OBD-II Body (B) Trouble Code |
| System: | Body |
| Vehicle: | Mitsubishi A10 |
| Brand: | Mitsubishi |
| Model: | A10 |
| Code: | B1805 |
B1805 Mitsubishi A10 Symptoms
Check Engine Light
Illuminated Mitsubishi A10 dashboard warning
Engine Stalling
Engine stops unexpectedly or misfires
Performance Issues
Reduced power or acceleration on the Mitsubishi A10
Starting Problems
Difficulty starting the engine
Poor Fuel Economy
Increased fuel consumption on the Mitsubishi A10
Increased Emissions
Failed emissions test due to B1805
B1805 Code Structure
Understanding what each digit means in the B1805 body trouble code:
| B | 1 | 8 | 0 | 5 |
|---|---|---|---|---|
| Body Code | Fuel And Air Metering | Engine Oil Temperature Sensor Malfunction | Cold Start Injector 1 Malfunction | Crankshaft Position Sensor B Circuit Malfunction |
How to Fix Mitsubishi A10 B1805
Diagnostic Steps:
Regarding B1805, carefully inspect the wire harness near the intake manifold bracket, best accessed from below near the oil filter. Look for chafing, pinching, or damaged insulation.
Repair Solution:
Verify all electrical connections are clean and tight. Check for damaged wiring, especially in high-heat or high-vibration areas. Use manufacturer wiring diagrams for accurate diagnosis.
Technical Notes:
B1805 on electronically controlled automatic transmissions relates to shift solenoid operation. The solenoid actuates hydraulic circuits controlling clutches or bands for gear changes.
Mitsubishi A10 B1805 Repair Cost
Torque converter clutch solenoid replacement on the Mitsubishi A10 — relevant for owners who tow regularly — costs $280–$480. A full transmission fluid change ($120–$160) at the same service is recommended because contaminated fluid accelerates solenoid wear.
B1805 Description
B1805 engine trouble code is related to Crankshaft Position Sensor B Circuit Malfunction.
Main Cause
The primary reason for B1805 OBD-II Engine Trouble Code is: Engine Oil Temperature Sensor Malfunction.
Common B1805 Misdiagnosis on the Mitsubishi A10
The Mitsubishi A10 knock sensor shares its harness with the coolant temperature sensor. A corroded shared ground causes both sensors to report out-of-range values simultaneously, leading to misdiagnosis of B1805 as a knock sensor fault when the root cause is the shared ground splice.
DIY Repair Guide: B1805 on Mitsubishi A10
Replacing the spark plugs on the Mitsubishi A10 is rated a difficulty 2/5 for home mechanics. The top-mounted plug access on this engine requires a 3/8" extension and a 14mm spark plug socket. Always torque to the manufacturer's specification to avoid cracking the cylinder head.
Preventing B1805 on the Mitsubishi A10
Scheduled inspection of the Mitsubishi A10 air filter every 15,000 miles can prevent the intake restriction that leads to B1805. A blocked filter forces the engine to run rich, stressing the catalytic converter and ultimately storing fault codes.
Frequently Asked Questions — Mitsubishi A10 B1805
A: Contaminated or low-octane fuel can temporarily trigger B1805 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.