The control module detected that the expected Engine status signal fault was absent. Documented for the Bosch MED 17.4.x engine ECU (EP6 THP family) on Peugeot applications; the same PSA control units are also fitted to Citroën models.
TuningBot DTC Database · v4.37.15
P1657 PSA - Diagnostic Trouble Code (4 interpretations)
Manufacturer-specific interpretation for PSA. All interpretations of P1657
What P1657 means
The control module detected that the expected Engine status signal fault was absent. Documented for the Bosch MEV17.4 engine ECU (EP6 1.6 VTi) on Peugeot applications; the same PSA control units are also fitted to Citroën models.
The control module detected an interruption (open circuit) in the Engine running status information line circuit. Documented for the Continental SID 807 injection ECU (DV6C 1.6 HDi) on Peugeot applications; the same PSA control units are also fitted to Citroën models.
The control module detected an interruption (open circuit) in the Engine running information circuit. Documented for the Magneti Marelli MM6KP engine ECU (EW7A/EW10A) on Peugeot applications; the same PSA control units are also fitted to Citroën models.
Related and nearby codes
How to read P1657
Powertrain: engine, transmission and driveline systems.
Manufacturer-defined range: the meaning can differ between brands.
Specific fault index within the subsystem.
Frequently asked questions about P1657
What does P1657 mean?
Diagnostic Trouble Code (4 interpretations). The control module detected that the expected Engine status signal fault was absent. Documented for the Bosch MED 17.4.x engine ECU (EP6 THP family) on Peugeot applications; the same PSA control units are also fitted to Citroën models.
Is P1657 generic or manufacturer-specific?
P1657 is a manufacturer-specific code. In this database it is documented for: PSA. The same number can mean something different on other brands.
Can TuningBot remove P1657 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.
Other file services
Understand the system behind this code: Diagnostic Strategy and DTC Logic
