Plymouth Horizon B1805 Engine Trouble Code
What is Plymouth Horizon B1805?
When Plymouth Horizon 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 Plymouth Horizon
For Plymouth Horizon 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: | Plymouth Horizon |
| Brand: | Plymouth |
| Model: | Horizon |
| Code: | B1805 |
B1805 Plymouth Horizon Symptoms
Check Engine Light
Illuminated Plymouth Horizon dashboard warning
Engine Stalling
Engine stops unexpectedly or misfires
Performance Issues
Reduced power or acceleration on the Plymouth Horizon
Starting Problems
Difficulty starting the engine
Poor Fuel Economy
Increased fuel consumption on the Plymouth Horizon
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 Plymouth Horizon 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:
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:
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.
Plymouth Horizon B1805 Repair Cost
For Plymouth Horizon 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 Plymouth Horizon
A common error on the Plymouth Horizon is attributing B1805 to the crankshaft position sensor when the real fault is a damaged flywheel ring gear. The missing tooth pattern created by ring gear damage is intermittent and generates the same signal anomaly.
DIY Repair Guide: B1805 on Plymouth Horizon
The fuel pressure test on the Plymouth Horizon 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 Plymouth Horizon
Transmission fluid degradation on the Plymouth Horizon directly affects solenoid operation. Replacing ATF at 40,000-mile intervals (rather than the often-quoted 'lifetime fill' recommendation) is the best insurance against shift-solenoid codes including B1805.
Frequently Asked Questions — Plymouth Horizon B1805
A: Temporarily clearing B1805 can help determine whether it is intermittent or persistent, but it does not fix the underlying fault. The code will return if the problem is still present. Do not clear codes just before an emissions test without a proper drive cycle.