What does code P1635 mean?

Q: What does code P1635 mean?

5V Reference Voltage to Sensors Low. P1635 on GM vehicles means the powertrain control module (PCM) has detected that the shared 5-volt reference circuit feeding multiple sensors has dropped below its expected operating range. The PCM monitors this supply line and sets the code when the voltage falls low enough that sensor readings can no longer be trusted, which can affect engine management and transmission shifting.

DTC codes / GM codes / P1635

P1635 · GM5V Reference Voltage to Sensors Low

P1635 on GM vehicles means the powertrain control module (PCM) has detected that the shared 5-volt reference circuit feeding multiple sensors has dropped below its expected operating range. The PCM monitors this supply line and sets the code when the voltage falls low enough that sensor readings can no longer be trusted, which can affect engine management and transmission shifting.

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.