What does code P1694 mean?

Q: What does code P1694 mean?

Tachometer Circuit Voltage High. P1694 on a GM vehicle means the powertrain control module (PCM) has detected an abnormally high voltage on the tachometer signal circuit, which is the wire that carries engine speed pulses from the ignition system to the instrument cluster. The PCM monitors this circuit and sets the code when the voltage exceeds the expected range for the current engine operating conditions, indicating an open circuit, a short to voltage, or a faulty tachometer driver.

DTC codes / GM codes / P1694

P1694 · GMTachometer Circuit Voltage High

P1694 on a GM vehicle means the powertrain control module (PCM) has detected an abnormally high voltage on the tachometer signal circuit, which is the wire that carries engine speed pulses from the ignition system to the instrument cluster. The PCM monitors this circuit and sets the code when the voltage exceeds the expected range for the current engine operating conditions, indicating an open circuit, a short to voltage, or a faulty tachometer driver.

SystemPowertrain

Code typeGM specific

SeverityLow

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.