What does code P1686 mean?

Q: What does code P1686 mean?

Driver 5 Line 6. P1686 on GM vehicles indicates that the powertrain control module (PCM) has detected a fault on the serial data communication line it uses to talk to the instrument cluster, specifically the circuit labeled Driver 5 Line 6 in GM's class 2 data bus. The PCM monitors this line for expected voltage changes and sets the code when the signal is missing, intermittent, or out of range, which typically prevents the cluster from displaying certain warnings or receiving commands.

DTC codes / GM codes / P1686

P1686 · GMDriver 5 Line 6

P1686 on GM vehicles indicates that the powertrain control module (PCM) has detected a fault on the serial data communication line it uses to talk to the instrument cluster, specifically the circuit labeled Driver 5 Line 6 in GM's class 2 data bus. The PCM monitors this line for expected voltage changes and sets the code when the signal is missing, intermittent, or out of range, which typically prevents the cluster from displaying certain warnings or receiving commands.

SystemPowertrain

Code typeGM specific

SeverityMedium

Fix difficultyIntermediate

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.