P0697

What it means

The 5-volt sensor reference rail C is open — the module supplies no voltage on this circuit. Every sensor powered from reference C loses its supply and reads invalid, so the ECU substitutes default values and may limit engine operation. Causes: a broken reference wire, a disconnected connector, or an internal open in the module's voltage regulator for rail C.

Is it safe to drive?

The vehicle is usually drivable for short distances, but the problem can worsen or affect emissions. Diagnose and repair as soon as practical.

Most likely causes

• Open in shared reference rail

  high

  One of the most commonly reported causes for this code — check this first.

• Pin pushed back out of connector body

  low

  Less common, but worth ruling out after the more likely causes.

• Cracked solder joint inside the module or sensor

  low

  Less common, but worth ruling out after the more likely causes.

Related help

• Full P0697 diagnosis, causes & costs
• How to read check engine light codes
• Is it safe to drive with the light on?