Jeep Grand Cherokee P0725 Code: No Gauges Working, Security Light On
My 2002 Jeep Grand Cherokee with a 4.7L V8 engine has suddenly stopped displaying any gauges on the dashboard. The vehicle runs and cranks over normally, but all instruments—such as speed, fuel, and temperature—are completely non-functional. I've already replaced the input and output engine speed sensors, cleared the P0725 code (Engine Speed Sensor Circuit), and even had the ECU replaced with a new one programmed for the year. Despite these efforts, the gauges remain unresponsive. The vehicle shows mileage in the upper-right corner with an 'O' symbol and a key icon, which stays lit. The security light is on and cannot be cleared. I've tried various troubleshooting methods including key reprogramming and ignition cycle tricks, but nothing has resolved the issue. No other diagnostic codes are present. I'm seeking advice—could this be related to a key programming issue? Is there a known fault with the 4.7L V8 engine's speed sensor circuit or ECU communication that affects gauge display? Any guidance on diagnosing or fixing this would be greatly appreciated, as my Jeep has been out of service for over two months.
Are there any other diagnostic trouble codes present? It's recommended to use a scanner with transmission-specific diagnostics. Which engine variant? The 4.0L or the -4.7L V8? P0725 - Engine Speed Sensor Circuit This could indicate a bus communication issue—what does the mileage display show? Is the airbag warning light illuminated?