2004 Chrysler Pacifica: P0700, P0440, and P0522 OBD2 Fault Codes - Diagnosis & Fixes
After replacing the thermostat on my 2004 Chrysler Pacifica, I noticed the check engine light came on with fault codes P0700, P0440, and P0522. The vehicle was restarted after the repair, but the issue persists. I used a key-on-off cycle to reset the system, and initially cleared the P0700 code. However, my son reported that during his commute home, the check engine light reappeared with new codes: P0440 (Evaporative Emission System Malfunction) and P0522 (Engine RPM Sensor Issue). He also noted a burnt oil smell and found oil residue in the antifreeze reservoir. I suspect a potential internal leak or sensor fault, but further diagnostics are needed.
The P0700 code is a generic transmission diagnostic trouble code indicating that there are additional transmission-related issues present. Did you use an OBD2 scanner or perform a key-on-off reset? Was the battery disconnected prior to any work? Were the ignition and key left on during repairs? Please review your workspace — ensure no wires were unplugged or moved. Additionally, check all fuses, especially those under the hood. A proper scan tool is essential for accurate diagnosis.