P0697 Sensor Reference Voltage C Circuit/Open

P0697 indicates Sensor Reference Voltage C circuit is open or unavailable. Sensors sharing the C reference may lose their expected supply voltage.

Code status

Needs verification

Not yet verified against SAE J2012_202509 / J2012DA. Treat unverified rows as a lookup aid, not repair authority.

System: Computer
Scope: iso-sae-controlled-p0
Standard: SAE J2012 / ISO 15031-6
Source: legacy-import

Diagnostic boundary

A diagnostic trouble code reports that a monitored test failed. It does not prove one specific part is bad, and manufacturer logic can add vehicle-specific conditions.

Do not replace multiple sensors until the shared reference C circuit is measured and isolated branch by branch.

Useful checks before replacing parts

Identify every sensor on reference circuit C, then compare reference voltage, signal voltages, grounds, freeze-frame data, and companion sensor codes.
Inspect open reference wiring, one shorted sensor loading the shared circuit, water intrusion, rubbed harness sections, and connector terminal damage.
Disconnect affected sensor branches according to service information to isolate whether the fault is a sensor, harness, or controller output.

Related OBD-II codes

These nearby computer entries can help compare wording and fault area. They may share the same verification status as the source database.