P0700 doesn't pinpoint the exact issue; it's a "catch-all" code that requires further diagnosis. To find the root cause, a mechanic will need to:
* Use a scan tool: A more advanced scan tool than a basic code reader is needed to read the accompanying codes (there will almost certainly be other, more specific codes along with P0700) that provide more details on the exact problem within the transmission system. These could relate to sensors, solenoids, wiring, or the transmission control module (TCM) itself.
* Inspect wiring and connectors: Look for damaged, loose, or corroded wiring harnesses and connectors related to the transmission.
* Check fluid levels and condition: Low, dirty, or burnt transmission fluid can cause numerous problems.
* Test the transmission control module (TCM): The TCM is the "brain" of the transmission. Problems here can cause a wide range of issues.
* Inspect sensors and solenoids: Various sensors and solenoids within the transmission monitor and control its operation. Faulty components in this area are common culprits.
Possible causes indicated by P0700 could include:
* Low transmission fluid: This is the easiest and cheapest thing to check first.
* Faulty transmission speed sensor: This sensor provides crucial information to the TCM.
* Faulty shift solenoids: These control gear shifting.
* Internal transmission problems: More serious internal issues like worn clutches or planetary gears can also trigger the code.
* Wiring harness issues: A short circuit or open circuit in the wiring can disrupt communication.
* Faulty TCM: The TCM itself might be malfunctioning.
In short, P0700 is a warning sign; it's crucial to get a proper diagnosis from a mechanic to identify and resolve the underlying problem before it causes more serious damage to your transmission. Ignoring it could lead to significant and costly repairs.
