This code indicates that the Powertrain Control Module (PCM) has detected a lower than expected voltage in the control circuit for the exhaust pressure regulator vent solenoid. This usually points to an electrical issue, such as a short to ground or an open circuit, rather than a mechanical failure of the solenoid itself. The PCM cannot properly control the solenoid when the circuit voltage is out of specification.
Chafed, corroded, or broken wiring in the solenoid control circuit is the most common cause, leading to a loss of voltage or an unintended ground path.
The internal coil of the solenoid may have shorted or failed, altering the electrical resistance and causing the low voltage condition.
Corroded, pushed-back, or loose terminals in the solenoid or PCM connectors can interrupt the circuit and trigger this code.
A blown fuse in the power supply circuit for the solenoid will result in zero voltage at the component, causing the PCM to detect a low circuit condition.
A failure of the internal driver circuit within the PCM is highly unlikely and should only be considered after all external wiring and components are verified.
You can typically drive short distances, but the vehicle may exhibit reduced performance and will likely fail an emissions test. It is best to diagnose the issue promptly to prevent potential secondary issues.
No. Drivers are often told to replace the PCM for this code, but that is almost always incorrect. The root cause is overwhelmingly found in the external wiring, connectors, fuses, or the solenoid itself. The PCM is the last component to suspect.
'Circuit low' means the PCM is reading a voltage on the control wire that is lower than the expected operational threshold. This typically indicates a short to ground, an open circuit, or a lack of power reaching the solenoid.
You must test the solenoid's resistance directly at the component. If the solenoid tests fine, the issue lies in the wiring, connectors, or the power supply leading to it.