What does code P1677 mean?

Q: What does code P1677 mean?

Driver 4 Line 7. P1677 on GM vehicles means the powertrain control module (PCM) has detected a fault on the driver 4 line 7 communication circuit, which is part of the class 2 serial data bus used for module-to-module messaging. The PCM monitors this line for expected voltage transitions and flags the code when the signal is missing, shorted, or implausible for a calibrated amount of time.

DTC codes / GM codes / P1677

P1677 · GMDriver 4 Line 7

P1677 on GM vehicles means the powertrain control module (PCM) has detected a fault on the driver 4 line 7 communication circuit, which is part of the class 2 serial data bus used for module-to-module messaging. The PCM monitors this line for expected voltage transitions and flags the code when the signal is missing, shorted, or implausible for a calibrated amount of time.

SystemPowertrain

Code typeGM specific

SeverityMedium

Fix difficultyProfessional

AreaComputer and output circuits

Guidance is general and written for GM vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.