P0700 Diagnostic for 2004 Chrysler PT Cruiser GT Turbo: TCM vs Solenoid Issue in Cold Weather
I own a 2004 Chrysler PT Cruiser GT Turbo with 144,000 miles and two previous owners. The vehicle has recently started throwing Diagnostic Trouble Code (DTC) P0700, which indicates either a faulty Transmission Control Module (TCM) or a solenoid issue in the automatic transmission. The problem is temperature-dependent: when temperatures drop below 50°F, the transmission does not engage gears until it has warmed up for nearly an hour. After that, gear engagement becomes inconsistent—sometimes working, sometimes failing. However, during warmer weather (above 50°F), the car shifts smoothly and operates normally. The transmission fluid appears clean with no burnt odor, and we have never changed the fluid or filter since purchasing the vehicle at 141,000 miles. The original owner reportedly maintained it well. The Check Engine Light (CEL) has now come on for the first time in over a year, and my OBD2 scanner confirms P0700. My son is a mechanic but lives several hours away. I'm seeking guidance to determine whether to troubleshoot the TCM or the transmission solenoid pack. Any additional insights—especially regarding fluid type, relay checks, or wiring issues—are greatly appreciated. Thanks in advance! PJ
Suggestion: Get a second OBD2 scan at most auto parts stores—free and often more accurate than personal scanners. For Mopar vehicles, a stuck transmission relay can trigger P0700 as the Powertrain Control Module (PCM) may misinterpret signals. Note: GTG