Code P2054 indicates that the powertrain control module has detected a lower-than-expected voltage on the control circuit for the reductant (DEF/urea) injection valve on Bank 1 Unit 2. This valve is part of the selective catalytic reduction (SCR) system, which injects diesel exhaust fluid into the exhaust stream to reduce NOx emissions. A 'low' circuit reading typically points to a short to ground, an open circuit, or a failed injection valve.
The dosing valve itself can fail internally due to electrical short, open coil, or crystallized DEF damage, causing the circuit voltage to read low. This is the most common root cause for this code.
Chafed, corroded, or broken wiring between the PCM and the injection valve can create a short to ground or open circuit, triggering a low-voltage reading. Harness routing near hot exhaust components makes this a frequent failure point.
Corroded, bent, or pushed-back terminals at the valve connector or intermediate harness connectors can cause high resistance or intermittent contact, leading to a low circuit signal at the PCM.
Contaminated or expired diesel exhaust fluid can crystallize inside the valve, causing mechanical binding and eventual electrical failure. This can damage the valve coil and produce a circuit fault.
The internal driver circuit in the PCM that controls the valve can fail, producing a false low-voltage reading. This is rare and should only be considered after all wiring, connectors, and the valve itself have been conclusively tested.
Short distances may be possible, but most diesel vehicles will eventually enter a derate or speed-limiting mode to protect emissions compliance. Prolonged driving with an inoperative SCR system can lead to a no-start condition on some vehicles.
No. This is a common but usually incorrect diagnosis. The vast majority of P2054 cases are caused by a failed reductant injection valve, damaged wiring, or a corroded connector. The PCM driver circuit is rarely the root cause and should only be replaced after exhaustive testing of all external components.
No. P2054 specifically relates to the electrical control circuit of the reductant injection (dosing) valve on Bank 1 Unit 2. DEF pump or tank heater issues will typically set different codes.
Yes, indirectly. Contaminated, expired, or diluted DEF can crystallize inside the injection valve, causing mechanical damage and eventual electrical coil failure that triggers P2054.