Mazda Lantis B1805 Engine Trouble Code
What is Mazda Lantis B1805?
With Mazda Lantis B1805, you may drive for several weeks with a malfunctioning MAF sensor, but expect decreased fuel economy and eventual stalling. Shop replacement costs $240–$400 depending on vehicle. The labour is straightforward, with most cost from the part itself.
B1805 on the Mazda Lantis
Service bulletins for the Mazda Lantis specifically mention B1805 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: | Mazda Lantis |
| Brand: | Mazda |
| Model: | Lantis |
| Code: | B1805 |
B1805 Mazda Lantis Symptoms
Check Engine Light
Illuminated Mazda Lantis dashboard warning
Engine Stalling
Engine stops unexpectedly or misfires
Performance Issues
Reduced power or acceleration on the Mazda Lantis
Starting Problems
Difficulty starting the engine
Poor Fuel Economy
Increased fuel consumption on the Mazda Lantis
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 Mazda Lantis B1805
Diagnostic Steps:
Poor running symptoms align with MAP sensor malfunction. In some cases, a faulty MAP sensor will not trigger a code. The issue may represent separate wiring concerns requiring individual diagnosis.
Repair Solution:
Power steering pressure switch monitors system operation. If pressure changes are not detected after calibrated speed transitions, this DTC sets. Verify PSP switch operation and check for circuit opens or shorts.
Technical Notes:
B1805 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.
Mazda Lantis B1805 Repair Cost
A complete diagnostic health-check on the Mazda Lantis before committing to any single repair costs $120–$180 at a dealership with live-data capability. This investment pays for itself if it prevents unnecessary part replacement, which is the single most common mistake when diagnosing B1805.
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 Mazda Lantis
Workshop technicians sometimes replace the entire ignition coil assembly on the Mazda Lantis when B1805 accompanies a cylinder-specific misfire. In many cases, only the spark plug in the misfiring cylinder has fouled; a $8 plug replaces a $140 coil pack.
DIY Repair Guide: B1805 on Mazda Lantis
Battery terminal cleaning on the Mazda Lantis is a 5-minute job that resolves a surprising number of B1805 intermittents. Use a wire brush and a bicarbonate of soda solution to clean corrosion, then apply a thin coat of petroleum jelly to the terminals after refitting.
Preventing B1805 on the Mazda Lantis
Keeping the Mazda Lantis battery in good health — testing specific gravity annually and replacing at first sign of degradation — protects the ECU voltage supply. Voltage drops during cranking cause sensor reading spikes that can spuriously store B1805.
Frequently Asked Questions — Mazda Lantis B1805
A: It depends on the severity. If the check-engine light is steady, it is generally safe to drive to a workshop within the next few days. If the light is flashing, pull over safely as soon as possible — a flashing light indicates an active misfire that can cause expensive catalytic converter damage within minutes.