Powertrain, generic · Computer and auxiliary outputs

P06A9 Sensor Reference Voltage D Circuit Range/Performance

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 and all its sensors report at once – unplug them one by one to find the culprit. P06A9 is the range/performance check of reference circuit D. No manufacturer document available to us uses this code; the description follows the other reference circuits. Ford checks circuits A–C this way (below 4.7 V or above 5.2 V); GM reports circuit D under the collective code P06A3, where pedal sensor 1 and the throttle sensors are typically connected – so electronic throttle limp mode is likely.

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 or components

Symptoms

  • Check engine light
  • Several sensor codes at once
  • Reduced power or limp mode
  • 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

P06A3P06A4P06A5P06A8P06A6

References: law.cornell.edu, newtonnet.co.uk, gsi.ext.gm.com.