P0700: Transmission Control System Malfunction (MIL Request)
Key takeaways
- P0700 is a pointer code: the transmission control module found a problem, stored its own code, and asked the engine computer to turn on the check engine light.
- A basic code reader often shows only P0700; a scan tool that talks to the transmission module is needed to see the code that says what is actually wrong.
- Check the transmission fluid level and condition first, because low or burnt fluid causes many of the codes behind P0700.
- Many cars go into a limp mode with P0700, holding one gear; drive it gently and only as far as a shop.
What P0700 means
Your transmission’s computer found a problem and asked the engine computer to turn on the check engine light. Scanners call it Transmission Control System Malfunction or Transmission Control System (MIL Request). On most cars the transmission control module (TCM) is separate from the engine computer. When it detects a fault, it stores its own detailed code and sends a request for the light, and the engine computer records that request as P0700. So P0700 is a pointer, not a diagnosis: the real answer is the code sitting in the TCM.
Is it safe to drive?
Short trips, gently. Many cars with P0700 go into limp mode: the transmission holds a single gear so it can’t hurt itself, and the car feels slow and revs high on the highway. What changes the answer: slipping, a flare in rpm between gears, harsh bangs into gear, no drive or reverse, or a burnt smell. Any of those, stop driving and tow it. Driving a slipping transmission turns a solenoid job into a rebuild.
Causes, ranked
P0700 never shows up for no reason; the TCM code behind it decides the repair. These are the common findings, most likely first.
| Cause | How you confirm it | Typical cost (US independent shop, 2026) |
|---|---|---|
| Low, old or burnt fluid | Fluid level and condition on the dipstick or check plug; leaks underneath | $20–$100 top up; $150–$300 fluid service |
| Wiring or connector at the transmission or TCM | TCM circuit code, corrosion or oil in the connector, chafed harness | $100–$250 |
| Shift or pressure control solenoid | Solenoid code in the TCM (P075x, P076x and similar), shift quality | $300–$1,200 solenoid or valve body |
| Speed sensor or range sensor | Input/output speed sensor code such as P0715 or P0720, erratic speedometer | $150–$400 |
| Software or a known bulletin condition | A bulletin for your car, or a code that clears and doesn’t return after an update | $100–$200 |
| Transmission control module | TCM communication or internal fault codes, verified power and grounds | $500–$1,500 including programming |
| Internal damage (clutches, torque converter) | Gear ratio codes like P0730, slipping, metal in the fluid | $3,000–$5,500 rebuild or replacement |
What to check first
- Read the TCM code. A basic reader may show only P0700. A shop scan tool, or a better app-based reader, can read the transmission module directly. Write the code down before anyone clears it.
- Check the fluid. Level, color and smell. Red or pink and clean is good; brown, black or burnt-smelling is not. If you see red drips, the red fluid leak guide helps.
- Look for a bulletin on your exact car and model year before buying parts.
- Inspect wiring and connectors at the transmission and the TCM.
- Then test the part the TCM code names: solenoid, sensor or module.
- Don’t clear it and drive as a fix; the TCM will set it again.
Bulletins show a pattern, led by GM. For 2023–2025 Silverado 1500, Sierra 1500 and CT5 and 2023–2024 CT4, GM gives a procedure to check whether P0700 with P18AE returns and clear it; others cover 2020–2023 heavy-duty Silverado and Sierra and 2024 Colorado and Canyon with specific repairs. Honda has one tying P0700 to a mild engine misfire on 2023 CR-V and Accord hybrids.
What it costs
The cheap outcome is a fluid top-up or a software update, $100 to $300 including the scan. The common outcome is wiring, a sensor or a solenoid at $100 to $1,200. The expensive outcome is internal damage and a rebuilt or replacement transmission at $3,000 to $5,500. Paying for a proper transmission scan first is how you avoid being sold the expensive answer. If you want help reading the TCM code you got, ask our AI mechanic.
Related codes
P0700 almost always comes with at least one transmission code: a solenoid code like P0750, a torque converter clutch code like P0741 or P0740, or a speed sensor code. If it jerks when shifting, see car jerks while driving. 266 complaints filed with NHTSA mention P0700; the Chevrolet Silverado 1500 (29), GMC Sierra 1500 (16) and GMC Acadia (12) lead. A complaint is an owner report, not a confirmed cause.
What owners report to NHTSA
266 complaints filed with NHTSA mention P0700, 208 of them since 2015, across 90 different models. The component owners most often filed it under: power train.
Most-reported models
| Vehicle | Complaints | Model years reported |
|---|---|---|
| CHEVROLET SILVERADO 1500 | 29 | 2016, 2020, 2021, 2022, 2024 |
| GMC SIERRA 1500 | 16 | 2015, 2016, 2017, 2022, 2023 |
| GMC ACADIA | 12 | 2007, 2008, 2020, 2021 |
| CHEVROLET EQUINOX | 11 | 2005, 2009, 2010, 2011, 2012 |
| CHEVROLET MALIBU | 9 | 2010, 2011, 2012, 2014, 2019 |
| SUZUKI FORENZA | 8 | 2005, 2006, 2007, 2008 |
| JEEP GRAND CHEROKEE | 6 | 2004, 2005, 2006 |
| CHEVROLET TRAVERSE | 6 | 2013, 2015, 2018, 2022, 2023 |
| CHEVROLET TAHOE | 6 | 2017, 2021, 2022 |
| SATURN VUE | 5 | 2003, 2008 |
Manufacturer service bulletins that name P0700
23 technical service bulletins and manufacturer communications filed with NHTSA mention P0700, from 9 makes. A bulletin means the manufacturer has documented a known cause or a fix procedure for that model. Examples:
- CADILLAC CT5 (2023, 2024, 2025), bulletin 11008967: This bulletin provides a procedure to perform a diagnostic check to verify if DTCs P18AE and/or P0700 Set returns when reset and to clear the codes and validate code does not set again.
- GMC SIERRA 1500 (2023, 2024, 2025), bulletin 11008967: This bulletin provides a procedure to perform a diagnostic check to verify if DTCs P18AE and/or P0700 Set returns when reset and to clear the codes and validate code does not set again.
- CHEVROLET SILVERADO 1500 (2023, 2024, 2025), bulletin 11008967: This bulletin provides a procedure to perform a diagnostic check to verify if DTCs P18AE and/or P0700 Set returns when reset and to clear the codes and validate code does not set again.
- CADILLAC CT4 (2023, 2024), bulletin 10246491: This bulletin provides a procedure to perform a diagnostic check to verify if DTCs P18AE and/or P0700 Set returns when reset and to clear the codes and validate code does not set again.
- GMC SIERRA 2500 (2020, 2021, 2022, 2023), bulletin 11005254: This technical bulletin provides repair information to correct a customer concern of Malfunction Indicator Lamp Illuminated, Stall, or No Start with DTC P2534, U3023, P0700, P129D, P10DB (w/ L5P Diesel), P103B, P17E0.
- CHEVROLET SILVERADO 3500 (2020, 2021, 2022, 2023), bulletin 11005254: This technical bulletin provides repair information to correct a customer concern of Malfunction Indicator Lamp Illuminated, Stall, or No Start with DTC P2534, U3023, P0700, P129D, P10DB (w/ L5P Diesel), P103B, P17E0.
Sources: NHTSA Office of Defects Investigation complaint database and manufacturer communications file, snapshots September 2026. A complaint or bulletin that mentions a code is a report about that vehicle, not a statement that the code has one cause.
Frequently asked questions
What does P0700 mean on my car?
It means the transmission computer has stored a fault of its own and asked for the check engine light. P0700 does not say what the fault is. Have the transmission module read with a scan tool that supports it; the code stored there, such as a shift solenoid or speed sensor code, is the one to diagnose.
Can I drive with a P0700 code?
Usually for short trips, gently. Many cars go into limp mode and hold one gear to protect the transmission, so acceleration and highway speed suffer. If the transmission slips, flares in rpm, won't engage, or smells burnt, stop driving it and get it towed.
Will clearing P0700 fix the problem?
No. Clearing it turns off the light, but the transmission module sets it again as soon as it sees the same fault. Some manufacturer bulletins do call for a check-and-clear procedure, but only after the underlying code has been looked at.
Does P0700 mean I need a new transmission?
Not usually. Low fluid, a wiring fault, a solenoid or a software update are more common answers than a rebuild. A rebuild only comes up once the transmission code, the fluid and a test drive point to internal damage.