P1621 Diagnostic Trouble Code (14 interpretations)

The control module detected a fault associated with the Speed Control Switch Always High circuit or function; the stored code identifies the affected component rather than a single failure mode. This is the manufacturer-specific definition used by Dodge.

The control module detected a fault associated with the Engine control module (ECM) circuit or function; the stored code identifies the affected component rather than a single failure mode. This is the manufacturer-specific definition used by Jaguar.

The control module detected a fault associated with the Immobilizer control module circuit or function; the stored code identifies the affected component rather than a single failure mode. This is the manufacturer-specific definition used by Land Rover.

The control module's internal test reported the Engine control module (ECM) as faulty. This is the manufacturer-specific definition used by Opel.

The stored code identifies a fault of the ECU internal fault. 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. PSA documentation does not characterise the failure mode further.

The stored code identifies a fault of the ECU internal fault. 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. PSA documentation does not characterise the failure mode further.

The control module detected the fault condition "Software redundancy fault at the injection (Level 2)" for the ECU. 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 the fault condition "Software redundancy fault at the injection. (trim level 2)" for the ECU. Documented for the Delphi DCM 3.5 injection ECU (DW10C 2.0 HDi) on Peugeot applications; the same PSA control units are also fitted to Citroën models.

The stored code identifies a fault of the ECU fault. Documented for the MCP 6-speed piloted manual gearbox ECU on Peugeot applications; the same PSA control units are also fitted to Citroën models. PSA documentation does not characterise the failure mode further.

The control module detected the fault condition "Safety" for the System fault. Documented for the Magneti Marelli MM6KP engine ECU (EW7A/EW10A) on Peugeot applications; the same PSA control units are also fitted to Citroën models.

The control module detected the fault condition "internal fault" for the Engine ECU. Documented for the Siemens SID 803 injection ECU (DW10BTED4 2.0 HDi) on Peugeot applications; the same PSA control units are also fitted to Citroën models.

The control module detected a communication fault involving Immobilizer control module/engine control module (ECM) on the vehicle network. This is the manufacturer-specific definition used by Suzuki.

The control module detected a short circuit to ground in the Instrument panel, ECT circuit. This is the manufacturer-specific definition used by Audi.

The control module detected a communication fault involving Instrumentation control module, real time clock on the vehicle network. This is the manufacturer-specific definition used by Volvo.