PowertrainP1666
CautionSeverity: Caution - get it checked when you can
Oxygen sensor malfunction
Key terms: Oxygen sensor: measures oxygen in the exhaust gas · Control module: a small computer that runs one part of the car · Powertrain: engine, transmission and emissions
1What it means in plain English
The engine or powertrain control system has stored a fault that does not have specific guidance in this database yet.
2Common causes
- Sensor or actuator fault
- Wiring or connector fault
- Vacuum or intake leak
- Fuel or ignition problem
- Control module fault
3Can I drive?
Have it diagnosed promptly. If the car runs and drives normally, drive gently to a workshop. If it runs badly, stalls, overheats, loses oil pressure, or a warning light is flashing or red, stop safely and get professional help. If the code concerns the brakes, brake vacuum or brake assist, do not drive until it is checked: a hard pedal or longer stopping distance means stop.
This page gives general information. It is not professional advice. For a definite diagnosis and a repair quote, ask a qualified mechanic to inspect the car.
4Brand data 27
| Brand | Code | Description | System |
|---|---|---|---|
| Ashok Leyland CV | P1666 | Fuel Pressure Regulator. Regulator 1. Open Circuit Brand | Powertrain |
| Mercedes-Benz | P1666 | No description available | Powertrain |
| BMW | P1666 | incorrect start value Brand | Powertrain |
| BYD | P1666 | Hydraulic oil cooling valve circuit short to power Brand | Powertrain |
| Chery | P1666 | EGR self-learning mechanical fault diagnosis Brand | Powertrain |
| Daewoo | P1666 | Driver 3 Line 6 Brand | Powertrain |
| DFFS | P1666 | Controller failure Brand | Powertrain |
| DFXK | P1666 | Valve for Pump-Jet: Cylinder 1 (N240): Electrical Malfunction Brand | Powertrain |
| EOBD | P1666 | Juht 3 liin 6 Brand | Powertrain |
| Ford | P1666 | No description available | Powertrain |
| Geely | P1666 | Valve for Pump-Jet: Cylinder 1 (N240): Electrical Malfunction Brand | Powertrain |
| GM | P1666 | Driver 3 Line 6 Brand | Powertrain |
| Great Wall | P1666 | Diagnostic fault check reported several errors when checking whole read only memory Brand | Powertrain |
| Holden | P1666 | Engine Shutdown Alarm Control Circuit Brand | Powertrain |
| Isuzu | P1666 | No description available | Powertrain |
| Land Rover | P1666 | No description available | Powertrain |
| Maserati | P1666 | Cruise control module internal Brand | Powertrain |
| Mazda | P1666 | No description available | Powertrain |
| Opel | P1666 | Driver 3 Line 6 Brand | Powertrain |
| Peugeot | P1666 | No description available | Powertrain |
| Porsche | P1666 | No description available | Powertrain |
| Saab | P1666 | Driver 3 Line 6 Brand | Powertrain |
| Smart | P1666 | No description available | Powertrain |
| Sprinter | P1666 | ENV_ _Datum2 Brand | Powertrain |
| Tata | P1666 | No description available | Powertrain |
| Toyota | P1666 | Oxygen sensor malfunction Brand | Powertrain |
| Volkswagen | P1666 | Valve for Pump - Jet: Cylinder 1 (N240): Electrical Malfunction Brand | Powertrain |
Legend: SAE is the generic J2012 description; Brand is text taken from that manufacturer’s data. Manufacturer rows keep the wording and language of the source data, and non-English text is tagged so screen readers pronounce it correctly.
5Extended variant codes 2
These 7-character codes are manufacturer-specific variants of P1666 and may be reported by some scan tools.
| Brand | Code | Description | System |
|---|---|---|---|
| Mercedes-Benz | P166600 | Sensor Brennraumdruck Zylinder 2 Modellplausibilitätsfehler Brand | Powertrain |
| Sprinter | P166600 | Sensor Brennraumdruck Zylinder 2 Modellplausibilitätsfehler Brand | Powertrain |
6Related codes
Browse Pxxx codes or P166xx codes.