Chevrolet Impala B1805 Engine Trouble Code
What is Chevrolet Impala B1805?
The Chevrolet Impala B1805 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.
B1805 on the Chevrolet Impala
A known issue on the Chevrolet Impala is that aftermarket air filter upgrades can inadvertently trigger B1805. High-flow filters alter the intake resonance frequency, causing the MAP sensor to report pressure readings outside factory calibration.
Code Information
| Code Type: | OBD-II Body (B) Trouble Code |
| System: | Body |
| Vehicle: | Chevrolet Impala |
| Brand: | Chevrolet |
| Model: | Impala |
| Code: | B1805 |
B1805 Chevrolet Impala Symptoms
Check Engine Light
Illuminated Chevrolet Impala dashboard warning
Engine Stalling
Engine stops unexpectedly or misfires
Performance Issues
Reduced power or acceleration on the Chevrolet Impala
Starting Problems
Difficulty starting the engine
Poor Fuel Economy
Increased fuel consumption on the Chevrolet Impala
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 Chevrolet Impala B1805
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:
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.
Chevrolet Impala B1805 Repair Cost
VVT actuator replacement on the Chevrolet Impala for B1805 is a more significant investment: $400–$700 including the oil flush required before fitting the new actuator. Using the correct low-SAPS engine oil after the repair is critical to prevent premature re-failure.
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 Chevrolet Impala
A common error on the Chevrolet Impala 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 Chevrolet Impala
Replacing the oxygen sensor on the Chevrolet Impala requires an O2 sensor socket (22mm or 7/8") and penetrating oil applied 24 hours in advance. On vehicles over five years old, the sensor threads often corrode into the bung; heat from a propane torch (briefly applied) is usually sufficient to free them.
Preventing B1805 on the Chevrolet Impala
To keep the Chevrolet Impala free of recurring B1805 faults, change the engine oil every 5,000–7,500 miles using a grade specified by Chevrolet. 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 — Chevrolet Impala 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.