Engine control module (ECM) - supply voltage
VAG · battery
Data confidence62%
The control module detected a fault associated with the Engine control module (ECM) - supply voltage circuit or function; the stored code identifies the affected component rather than a single failure mode. This is the manufacturer-specific definition used by Audi.
Possible causes
Wiring
engine control relay
Applies toAudi
P1601
Relay for Supply Voltage Terminal 30 (J317): Implausible Signal
VAG · battery
Data confidence80%
The control module judged the Relay for Supply Voltage Terminal 30 (J317) signal implausible when compared with other operating data. This is the manufacturer-specific definition used by Volkswagen. Volkswagen Group tools also report it as fault code 18009. Documented across Volkswagen Group applications (Audi, SEAT and Škoda included).
Symptoms
Engine does not start
Running problems incl. stopping Engine
Possible causes
Relay for Supply Voltage Terminal 30 (J317) stuck
Relay for Supply Voltage Terminal 30 (J317) faulty
Recommended checks
Check Voltage Supply for Engine Control Module (ECM)
Check/Replace Relay for Supply Voltage Terminal 30 (J317)
Powertrain: engine, transmission and driveline systems.
1
Manufacturer-defined range: the meaning can differ between brands.
601
Specific fault index within the subsystem.
Frequently asked questions about P1601
What does P1601 mean?
Diagnostic Trouble Code (2 interpretations). The control module detected a fault associated with the Engine control module (ECM) - supply voltage circuit or function; the stored code identifies the affected component rather than a single failure mode. This is the manufacturer-specific definition used by Audi.
Is P1601 generic or manufacturer-specific?
P1601 is a manufacturer-specific code. In this database it is documented for: VAG. The same number can mean something different on other brands.
Can TuningBot remove P1601 at file level?
If the fault logic lives in the ECU calibration, yes: our DTC Removal file service disables the specific fault entry. Checksum correction is not included: it is a separate, optional service. Not sure whether your case qualifies? Request a free assessment and our engineers will check your ECU file.