C3804 Engine Trouble Code
What is C3804?
C3804 code can indicate a faulty oxygen sensor, which may eventually damage the catalytic converter (repair cost: $2,000–$2,200). Professional diagnosis costs around $200–$210. Oxygen sensors are often straightforward to replace — check your owner's manual for location and instructions. This issue should be addressed promptly to prevent further damage.
Code Information
| Code Type: | OBD-II Chassis (C) Trouble Code |
| System: | Chassis |
| Code: | C3804 |
C3804 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
C3804 Code Structure
Understanding what each digit means in the C3804 chassis trouble code:
| C | 3 | 8 | 0 | 4 |
|---|---|---|---|---|
| Chassis Code | Ignition System Or Misfire | Engine Oil Temperature Sensor Malfunction | Cold Start Injector 1 Malfunction | Timing Reference High Resolution Signal A Too Many Pulses |
How to Fix C3804
Diagnostic Steps:
Regarding C3804, carefully inspect the wire harness near the intake manifold bracket, best accessed from below near the oil filter. Look for chafing, pinching, or damaged insulation.
Repair Solution:
Gasoline engines use spark plugs to ignite fuel-air mixture. Proper timing ensures the explosion occurs when the piston is positioned correctly. Incorrect plug wire sequencing causes mistimed ignition, resulting in poor performance.
Technical Notes:
C3804 DTC specifically relates to camshaft timing. When cam timing is over-retarded, the check-engine light illuminates and this code sets. Verify VCT solenoid operation and check for contamination.
C3804 Description
C3804 engine trouble code is related to Timing Reference High Resolution Signal A Too Many Pulses.
Main Cause
The primary reason for C3804 OBD-II Engine Trouble Code is: Engine Oil Temperature Sensor Malfunction.