Powertrain, generic (extended)

P2C23 Exhaust Heat Exchanger Exhaust Bypass Valve A Position Sensor Performance

Check engine lightOn

EmissionsRelevant

Drive cycleRequired

Limp modeNo

P2C23 means the flap position reported for exhaust heat exchanger bypass valve A is electrically valid but does not make sense – for example it disagrees with the command or with how the coolant behind the exchanger warms up. A Ford patent shows that such plausibility can be judged from temperatures. Ford documents P2C23 on several full hybrids: SSM 49531 notes it on 2021 F-150 PowerBoost trucks at or below freezing, TSB 21-2053 reprograms the PCM on trucks built up to 15 February 2021, and SSM 52543 (F-150, Explorer 3.3L, Escape 2.5L, Maverick, up to 2024) first checks the connectors of exhaust coolant temperature sensors 3 and 4 for water and corrosion before the heat exchanger is condemned. Driving is unaffected; the MIL is on.

Likely causes

Water or corrosion in the connectors of exhaust coolant temperature sensors 3/4 (Ford)

Outdated PCM calibration (early 2021 F-150 PowerBoost)

Worn, sticking or frozen bypass actuator

Flap or linkage in the heat exchanger binding

Symptoms

Check engine light, often after frost
No noticeable change in driving
Heater warms up more slowly

Repair estimate

DifficultyMediumWorkshop job

Parts and labour€50–1,500

Time0.3–4 h

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

Parts involved

exhaust heat exchanger bypass valve a pos sensorwiring harnessecm

Related codes

P2C22 P2C24 P2C25 P237F P25D6 P237C

References: static.nhtsa.gov, static.nhtsa.gov, static.nhtsa.gov, static.nhtsa.gov.