P0377 Engine Trouble Code
What is P0377?
P0377 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 Powertrain (P) Trouble Code |
| System: | Powertrain |
| Code: | P0377 |
P0377 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
P0377 Code Structure
Understanding what each digit means in the P0377 powertrain trouble code:
| P | 0 | 3 | 7 | 7 |
|---|---|---|---|---|
| Powertrain Code | Intake Valve Control Solenoid Circuit Low | Throttle/Pedal Position Sensor/Switch A Circuit Intermittent | Cylinder 10 Contribution/Balance Fault | Shift/Timing Solenoid Malfunction |
How to Fix P0377
Diagnostic Steps:
Regarding P0377, 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:
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:
P0377 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.
P0377 Description
P0377 OBD-II Trouble Code: The optical sensor provides a high resolution signal to the Powertrain Control Module (
Main Cause
The primary reason for P0377 OBD-II Engine Trouble Code is: Throttle/Pedal Position Sensor/Switch A Circuit Intermittent.