P0700 is a general notice rather than a specific fault - the transmission control module (TCM) has found a problem and is asking the engine computer to turn on the check-engine light.
Also written as PO700 or P700.
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P0700 is a general notice rather than a specific fault - the transmission control module (TCM) has found a problem and is asking the engine computer to turn on the check-engine light. On its own it tells you very little; you have to scan the TCM for the companion codes stored alongside it (for example a solenoid or speed-sensor code) to know the real issue. Always read the additional transmission codes before replacing any parts.
It depends on what else the code triggers. P0700 on its own is just a flag that a companion transmission code is stored - if the transmission is shifting normally, driving to get it scanned is fine. If the transmission has gone into limp/fail-safe mode (stuck in one gear, or shifting harshly), avoid highway driving and get it diagnosed promptly, since that mode is the computer protecting itself from a real fault.
Listed roughly most-likely first. Confirm with a scan tool and the freeze-frame data before replacing parts.
| Fix | DIY parts | At a shop |
|---|---|---|
| Service the transmission fluid and filter | $40 - $120 | $150 - $300 |
| Replace a shift or pressure control solenoid | $50 - $200 | $200 - $600 |
| Repair transmission wiring | $20 - $100 | $150 - $400 |
| Rebuild or replace the valve body | $300 - $900 | $800 - $2,500 |
Ranges are rounded and for the US market only - actual price depends on region, shop labor rates, and the exact make and model.
These open an Amazon search - add your year, make and model, because most of these parts are fitment-specific.
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P0700 is different from every other code on this site: it is not a fault in itself. It is the transmission control module telling the engine control module that it has stored a fault of its own and wants the check engine light turned on. The actual problem is described by a separate transmission code that a basic reader often cannot see. So the entire task with P0700 is retrieving the real code underneath it - and that usually requires a scanner capable of reading the transmission module, not just generic engine codes.
Accepting a transmission rebuild quote based on P0700 alone is the mistake to avoid, because this code says nothing about severity. It appears identically for a corroded connector and for a failed clutch pack. Insist on knowing the underlying code before authorising any work.
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Difficulty: Easy to diagnose, varies to repair. Time: 0.25 - 5 hours. DIY parts: $30 - $350. Shop total: $100 - $2,000.
Retrieving the underlying code is easy and cheap once you have the right scanner, and buying a scanner that reads transmission modules costs less than a single diagnostic fee at a shop. What the repair costs depends entirely on what that code turns out to be - anything from a fluid change to a rebuild. Get the real code before accepting any quote.
Service transmission fluid on a real interval and keep the record. Most faults that trigger P0700 trace back to degraded fluid. A documented service history also protects you at the shop - it is the difference between a diagnosis and an assumption that the transmission was neglected. Log every transmission service in ServiceSage. When a shop suggests a rebuild, a dated fluid history is the strongest evidence you have that the problem is something smaller. Track this maintenance free.
Typical US independent-shop repair cost for P0700 runs about $100 - $2,500, depending on the root cause. Common fixes: Service the transmission fluid and filter (about $150 - $300 at a shop); Replace a shift or pressure control solenoid (about $200 - $600 at a shop); Repair transmission wiring (about $150 - $400 at a shop); Rebuild or replace the valve body (about $800 - $2,500 at a shop).
No, not on its own. P0700 will keep coming back every time the relevant monitor re-runs until the underlying cause is actually repaired - clearing it with a scan tool without fixing what triggered it only delays the light coming back on.
Related trouble codes: P0740 - Torque Converter Clutch Circuit Malfunction