Powertrain
Definition only
Lights the check engine lamp
P23A2: Exhaust Heat Exchanger Bypass Valve B Control Circuit Open
Standardized SAE J2012 code · P23xx — Ignition system and misfire
What does P23A2 mean?
Exhaust Heat Exchanger Bypass Valve B Control Circuit Open: the control circuit is open. Likely a broken wire, disconnected connector, or failed actuator.
The code tells you which monitor failed, not which part is broken. Test before replacing parts.
Common causes
- High Open in harness or actuator
- Low Pin pushed back out of connector body
- Low Cracked solder joint inside the module or sensor
Likelihood is a general estimate across vehicles; your make and model may differ.
Add your car to see reports of P23A2 on the same make and model first.
P23A2 in the community
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