Hi.
If the transmission is in limp mode it means that the transmission problem has been detected and that there are diagnostic trouble codes (DTC) stored in main computer (ECM) and transmission control module (TCM). Since there is a number of different faults that may send the transmission in limp mode, the next step in troubleshooting is performing a code scanning.
A general OBDII code scanning can be performed for free at Autozone or can be done at home using a tool
like this:OBDII Scanner - U480. Such kind of scan will not be of much use, since it will not reveal the DTC stored in the transmission module (TCM). An OBDII code scanner will probably return the generic code P0700, indicating that a more complete scan must be performed (see:I get code p0700 after an OBDII scan.).
The code scanning needed must be done at the dealer place or at any authorized garage. You must expressly ask to scan the TCM (which means transmission control module, ask to scan TCM and not only the main computer called PCM, ECM or ECU).
A code scanning at the dealer or in a garage is not free. The scan is usually charged half hour labor, which is $30/$40.
Among parts that may cause transmission faults there are TPS (throttle position sensor), VSS (vehicle speed sensor), TCM, crankshaft sensor, transmission shift solenoids and transmission internal parts.
Before going for the code scanning you can check the transmission fluid level and color. If the fluid level is low or if fluid is very dark because saturated with metal particles, then transmission may go in limp mode as soon as the several faults generated from the fluid problem are detected.
Regards.
Ginko
