Powertrain, generic (extended)

P24D7 EVAP System Pressure Sensor/Switch B Circuit Low

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

P24D7 is set when EVAP pressure sensor B sends a voltage below its valid window. GM's 2023 table (23OBDG03A) watches its canister pressure sensor continuously and fails below 0.15 V, 3 % of the reference, with 640 of 800 samples, Type B; the sensor normally works between 0.5 and 4.5 V. Mitsubishi's 2023 Outlander PHEV uses a far higher floor for its absolute tank pressure sensor: under 1.0 V for 2 s. Audi's bulletin 2069531 shows P24D7 as pressure sensor 2 shorted to ground on 2022–2023 four-cylinder models and steers the test to sensor G950. Expect a signal wire grounded, a missing 5 V reference or a failed sensor. P24D8 is the high side, P24D6 a reading that is in range but wrong.

Likely causes

Signal wire of sensor B shorted to ground
5 V reference open or shorted
EVAP pressure sensor B failed

Symptoms

  • Malfunction indicator lamp on
  • EVAP tests suspended

Repair estimate

DifficultyMediumDIY possible
Parts and labour€50–350
Time0.5–1.5 h

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

Parts involved

evap pressure sensor b

Related codes

P24D8P24D6P24D5P24D9P0452

References: gsi.ext.gm.com, mitsubishitechinfo.com, static.nhtsa.gov.