P1693 BUICK, CADILLAC, CHEVROLET, GMC: TACHOMETER CIRCUIT CONDITIONS
POST UPDATED IN February, 2023
P1693 Code failures by brands
Description of DTC code P1693
The tachometer is used to measure how fast the engine shaft rotates, which is usually limited to various electrical or mechanical instruments. The tachometer indicates the vehicle driver the Revolutions Per Minute (RPM) that the object is making. This device consists of a needle that indicates current readings, a dial, and various markings that signal dangerous and safe levels.
The tachometer is installed on the vehicle’s dashboard, and its indicator basically indicates the resulting readings of the revolutions per minute of the engine’s driveshaft. This device is essential to carry out the regulation of the engine’s work. However, the way they take the measurements always varies.
When the P1693 OBDII fault code is set on GMC, Chevrolet, and other vehicles, it is because the tachometer circuit has experienced malfunctioning conditions. Specifically, the PCM (Powertrain Control Module) detected an open circuit, short to ground or short to voltage in the tachometer circuit with the key on.
Symptoms of fault code P1693
- Check Engine light ON.
Causes of OBD2 P1693
The reasons for storing the P1693 OBD2 diagnostic code P1693 are:
- The tachometer harness may have common deficiencies.
- The tachometer circuit connections may be damaged causing malfunction.
- The tachometer may be defective.
Possible solutions of the DTC code P1693
Steps to solve the DTC P1693 OBDII code:
- First, consult the Technical Service Bulletins.
- Check all the cables and connectors that relate to the tachometer. Look for any damage caused by corrosion, burns, or wear. If you discover such conditions, make repairs.
- Following the manufacturer's guidelines, measure the tachometer circuit voltages. Compare these readings with those indicated in the specifications and if discrepancies are discovered, make the necessary corrections.
