Gaz M-20 B1805 Engine Trouble Code
What is Gaz M-20 B1805?
When Gaz M-20 B1805 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.
B1805 on the Gaz M-20
For Gaz M-20 owners, diagnosing B1805 correctly requires ruling out a faulty camshaft position sensor before replacing more expensive components. The sensor wiring harness on this model runs close to the exhaust manifold and is prone to heat-related insulation damage.
Code Information
| Code Type: | OBD-II Body (B) Trouble Code |
| System: | Body |
| Vehicle: | Gaz M-20 |
| Brand: | Gaz |
| Model: | M-20 |
| Code: | B1805 |
B1805 Gaz M-20 Symptoms
Check Engine Light
Illuminated Gaz M-20 dashboard warning
Engine Stalling
Engine stops unexpectedly or misfires
Performance Issues
Reduced power or acceleration on the Gaz M-20
Starting Problems
Difficulty starting the engine
Poor Fuel Economy
Increased fuel consumption on the Gaz M-20
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 Gaz M-20 B1805
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:
Crankshaft position sensor signals the computer for precise ignition and fuel injection timing. Faulty sensors cause rough running and reduced efficiency. Modern vehicles enter limp mode and illuminate the check-engine light.
Technical Notes:
Parts or components should not be replaced based solely on B1805 DTC. Consult your vehicle service manual for proper diagnostic procedures, possible causes, and required testing before replacement.
Gaz M-20 B1805 Repair Cost
For Gaz M-20 owners, budget the following for a B1805 repair: EGR valve cleaning $80–$120 or replacement $250–$450, intake manifold gasket $120–$200, and a post-repair reset and road test. Total: $350–$650 at an independent garage.
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 Gaz M-20
The Gaz M-20 purge valve for the EVAP system is located in an area prone to heat damage. It is often overlooked in favour of replacing the carbon canister ($120–$200) when the valve itself ($25–$50) is the failed component for B1805.
DIY Repair Guide: B1805 on Gaz M-20
The fuel pressure test on the Gaz M-20 requires a Schrader-valve type fuel pressure gauge ($25–$40) connected to the fuel rail test port. With the ignition ON (engine off), pressure should hold above 30 PSI for two minutes. A rapid drop confirms a leaking injector or failing regulator as the root cause of B1805.
Preventing B1805 on the Gaz M-20
After any fuel system repair on the Gaz M-20, always perform a fuel-trim reset and adaptation drive. Skipping this step leaves the ECU operating on pre-repair learned values, which can generate false B1805 alerts for weeks after the fix.
Frequently Asked Questions — Gaz M-20 B1805
A: Not always. Across model years, Gaz revised sensor specifications, wiring paths, and ECU calibrations. Always confirm the repair procedure matches your specific vehicle's production year and engine code, as parts and labour times can vary significantly.