What are the common causes of P0697?

An open in the reference C feed wire. A short in the C circuit. A corroded C circuit connector. A failed sensor on the C circuit. A faulty ECM.

Check the 5 volt reference on the C circuit. Inspect the wiring and connectors. Unplug sensors one at a time to find the short. Test the ECM reference output. Repair the wiring or replace the ECM. Clear the code and retest.

P0697

Sensor Reference Voltage C Circuit/Open

System: Computer output circuits (P code)
Lamp: Check Engine Light
Category: Powertrain - Computer and Auxiliary Controls

What it means

P0697 means Sensor Reference Voltage C Circuit/Open.

Where it lives

For P0697, the circuit described runs through the sensor. The description of P0697 reports the sensor as open.

Check these first

An open in the reference C feed wire
A short in the C circuit
A corroded C circuit connector
A failed sensor on the C circuit
A faulty ECM

What to do next

Check the 5 volt reference on the C circuit
Inspect the wiring and connectors
Unplug sensors one at a time to find the short
Test the ECM reference output
Repair the wiring or replace the ECM
Clear the code and retest

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Updated

Generic SAE J2012 definition. Last updated 2026-10-10.