B0404 Engine Trouble Code
What is B0404?
The B0404 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.
Code Information
| Code Type: | OBD-II Body (B) Trouble Code |
| System: | Body |
| Code: | B0404 |
B0404 Symptoms
Check Engine Light
Illuminated dashboard warning
Engine Stalling
Engine stops unexpectedly or misfires
Performance Issues
Reduced power or acceleration
Starting Problems
Difficulty starting the engine
B0404 Code Structure
Understanding what each digit means in the B0404 body trouble code:
| B | 0 | 4 | 0 | 4 |
|---|---|---|---|---|
| Body Code | Intake Valve Control Solenoid Circuit Low | O2 Sensor Heater Circuit Malfunction | Cold Start Injector 1 Malfunction | Timing Reference High Resolution Signal A Too Many Pulses |
How to Fix B0404
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:
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:
B0404 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.
B0404 Description
B0404 engine trouble code is related to Timing Reference High Resolution Signal A Too Many Pulses.
Main Cause
The primary reason for B0404 OBD-II Engine Trouble Code is: O2 Sensor Heater Circuit Malfunction.