P0700 Transmission Control System Fault
Get it checked soon
P0700 is a messenger. The transmission computer found a problem and asked the engine computer to turn on the light. The real code is in the transmission module, so read that next.
- Safe to drive?
- Depends on how it shifts
- Typical cost at a shop
- $294-$1,006 RepairPal national averages, parts and labor
- Emissions test
- Yes, while the check engine light is on, most OBD emissions tests fail the car.
- Carmaker bulletins
- 2 notes with links
What it means
The transmission control module (TCM) found a fault, stored its own code and asked the engine computer to light the check engine light. P0700 is that request. The detail is in the transmission module, so the first job is to read codes from it. Many basic code readers cannot.
The technical version
On OBD II cars, emissions-related transmission faults must turn on the check engine light. Where the transmission has its own computer, the engine computer stores P0700 as a flag and the TCM stores the specific code. A scanner that queries every module shows both.
Official name: Transmission Control System Malfunction.
Symptoms
- Harsh or late shifts.
- Stuck in one gear (limp mode).
- Slipping.
- Sometimes no symptom.
Causes, most likely first
| Cause | How likely | How to tell |
|---|---|---|
| Any fault inside the transmission control system; the TCM code names it | most common | Read the transmission module. |
| Low or worn transmission fluid | common | Low level, dark color or burnt smell. |
| Shift solenoid or speed sensor faults | common | Codes such as P0715 in the TCM. |
| Wiring or connector damage between TCM and transmission | less common | Circuit codes in the TCM, see the GM bulletin in make notes. |
| Internal wear | less common | Slipping, flare between gears. |
How likely is our ranking from repair data and common practice, not a published rate.
What the live data shows
Module coverage matters here. A scanner that only asks the engine module shows P0700 and nothing else. Reading the transmission module shows the real code. Transmission fluid temperature is worth a look where the car reports it: very hot fluid with P0700 is its own answer.
What to check first, in order
-
Read the transmission module's codes.
The diagnosis starts there.
What the data shows: The TCM code, its freeze frame and status.
Cost: no cost if you have a scanner
-
Check fluid level and condition.
Low or burnt fluid causes many faults.
What the data shows: Transmission fluid temperature where supported.
Cost: free to check
-
Check the make notes for bulletins or warranty extensions.
Some transmissions have extended coverage.
What the data shows: No reading needed.
Cost: free
-
Follow the specific TCM code.
Solenoid, sensor, wiring or mechanical work.
What the data shows: Depends on the code.
Cost: $294-$356 at a shop (Transmission fluid change, RepairPal)
Is it safe to drive?
Get it checked soon
Depends on how it shifts. P0700 only says the transmission has a fault.
The severity is whatever the transmission code says, so find out fast. If the transmission shifts smoothly and does not slip, have it read soon. If it slips, bangs into gear or is stuck in one gear, have it seen now: driving a slipping automatic can destroy it quickly.
Stop driving and get help if
- The transmission slips or flares between gears.
- It is stuck in one gear on the highway.
- You smell burning fluid.
What it costs
| Repair | Typical cost |
|---|---|
| Transmission fluid changeRepairPal, updated September 3, 2026 | $294-$356 |
| Transmission control module replacementRepairPal, updated September 3, 2026 | $929-$1,006 |
National averages for the full job at a shop, parts and labor, from RepairPal (updated September 3, 2026). Your price depends on the car and the area. Many of the first checks on this page cost nothing with a scanner.
Can I clear it? Will it come back?
Clearing P0700 alone does not fix anything. Clear the TCM code after the repair and drive; watch that it does not return.
Will it fail an emissions test?
Yes, while the check engine light is on, most OBD emissions tests fail the car.
Carmaker notes
Service bulletins and warranty extensions that name this code. Ask a dealer to check your VIN.
-
GM 2007-2012 Silverado, Sierra, Tahoe, Suburban, Yukon, Avalanche, Escalade with 6L80 or 6L90
GM bulletin 08-07-30-021G (March 2012) lists P0700 and U0100 with loss of network communication, including terminals in the transmission harness connector.
GM 08-07-30-021G via NHTSA static.nhtsa.gov
-
Nissan 2014-2018 Rogue, 2015 Rogue Select, 2015-2018 Pathfinder
Nissan extended the CVT warranty from 60 months or 60,000 miles to 84 months or 84,000 miles (notice dated June 1, 2022). Check before you pay for a CVT repair.
Nissan CVT warranty extension via NHTSA static.nhtsa.gov
Related codes
Also related, no guide yet: P0740, P0741, P0720.
How Obie handles P0700
Obie reads codes from the transmission module as well as the engine, where the car answers, and tells you whether the shift symptoms mean soon or now. Obie is part of ScanMyCar Pro. Codes and live sensors are free.
Questions people ask
What does P0700 mean?
The transmission computer stored a fault. Read the transmission module to see which one.
Can I drive with P0700?
If it shifts normally, carefully and briefly. If it slips or is stuck in gear, have it seen now.
Why can my code reader not see the transmission code?
Many basic readers only ask the engine computer. You need a scanner that reads the transmission module.
Sources
- RepairPal: P0700 code page repairpal.com
- RepairPal: Transmission fluid change (updated September 3, 2026) repairpal.com
- RepairPal: Transmission control module replacement (updated September 3, 2026) repairpal.com
- GM 08-07-30-021G via NHTSA static.nhtsa.gov
- Nissan CVT warranty extension via NHTSA static.nhtsa.gov
- Texas DPS emissions testing FAQ dps.texas.gov
- Arizona myazcar.com: OBD and the check engine light myazcar.com
A guide, not a diagnosis. This page describes what P0700 generally means across OBD2 cars. What is actually wrong with your car depends on its live data and its history, and any repair decision deserves a proper diagnosis, whether that is you with a scanner or a professional with a lift.
