P0700 Toyota Highlander
Transmission Control System Malfunction · Powertrain Code · High
What is P0700?
A general transmission fault code indicating the transmission control module has detected a problem. Check for additional transmission codes.
When the Toyota Highlander triggers code P0700 (transmission control system malfunction), it typically points to an issue in the powertrain system. This is a high severity code, so address it promptly to avoid further damage or safety concerns. Below you'll find the most common causes, symptoms, and repair options specific to the Toyota Highlander.
Diagnostic data on this page is compiled from publicly available repair resources and technical service bulletins. Always have a qualified mechanic confirm the diagnosis before authorizing repairs on your Toyota Highlander.
Common Causes on Toyota Highlander
- Transmission control system malfunction — this is an informational code indicating other trans codes are stored
- Failed transmission solenoid(s) inside the valve body
- Low or degraded transmission fluid
- TCM (transmission control module) communication issue
Symptoms
- Check Engine Light on
- Transmission may shift harshly or slip
- Vehicle may be stuck in limp mode (3rd gear only)
- Delayed or no engagement when shifting from Park to Drive
- Transmission temperature warning (if equipped)
Notes for Toyota Highlander
P0700 is never the root cause — it is a flag that the TCM has stored its own codes; always read transmission-specific codes to identify the actual failure.