Powertrain, generic · Computer and auxiliary outputs

P0697 Sensor Reference Voltage C Circuit/Open

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

The engine module feeds sensors from several regulated 5 V reference circuits; a short at one sensor pulls the whole circuit down, so all its sensors report at once – unplug them one by one to find the culprit. Which sensors hang on circuit C depends on the maker – pedal sensor 2 is common to all: GM 2016–2025 feeds only pedal sensor 2 from it, the Saab 9-4X also the MAP sensor, the Saab 9-5 2.0 L turbo also throttle, crankshaft and A/C pressure sensors, and Bentley's 2026 Bentayga V8 lists its own set. P0697 is the general code for circuit C. GM puts all faults into it: reference outside 4.875–5.125 V or jumping, 19 of 39 counts or 0.19 s, lamp in the first trip; GM Europe's 2.0 L turbo also uses P0698/P0699.

Likely causes

Short in the wire or sensor of a connected sensor
Chafing or water in harness or connector
A connected sensor faulty internally
Module internal voltage regulator

Symptoms

  • Check engine light
  • Several sensor codes at once (pedal, throttle, pressure)
  • Electronic throttle limp mode, reduced power
  • Possibly starting problems

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€80–600
Time1–3 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

sensor reference voltage circuitsensor wiringengine control module

Related codes

P0698P0699P06A3P0651P0641P2127

References: law.cornell.edu, gsi.ext.gm.com, gsi.ext.gm.com, gsi.ext.gm.com.