P1277 Engine Trouble Code
What is P1277?
P1277 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: | P1277 |
P1277 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
P1277 Code Structure
Understanding what each digit means in the P1277 powertrain trouble code:
| P | 1 | 2 | 7 | 7 |
|---|---|---|---|---|
| Powertrain Code | Fuel And Air Metering | Manifold Absolute Pressure/Barometric Pressure Circuit High Input | Cylinder 10 Contribution/Balance Fault | Shift/Timing Solenoid Malfunction |
How to Fix P1277
Diagnostic Steps:
Regarding P1277, 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:
P1277 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.
P1277 Description
P1277 OBD-II Trouble Code: Cylinder #7 High To Low Side Open is one of the definitions for the P1277; however your vehicles manufacturer may have a different definition for the P1277 code. Please check below for your specific m
Main Cause
The primary reason for P1277 OBD-II Engine Trouble Code is: Manifold Absolute Pressure/Barometric Pressure Circuit High Input.