EngineLightCodes
Powertrain code

P0700 Transmission Control System (MIL Request)

Severity
Fix soon
Typical repair cost
$60–$1,650
Do it yourself
Shop job
Shop time
0.5–6 hours

The transmission computer found a problem and asked the engine computer to turn on the check engine light. P0700 itself doesn't say what's wrong: the real code is stored in the transmission module.

How the engine computer detects it

P0700 is a notice code: the separate transmission control module has stored an emission-related fault of its own and asks the engine module to switch on the check engine light. The actual fault – a sensor, solenoid, ratio or speed sensor code – is stored in the transmission module and must be read with a tool that can address it; simple OBD readers often show only P0700. GM's engine module reads the request message from 3 s after start; Subaru-based systems (Saab 9-2X) light the MIL at once and clear it after three fault-free cycles. Ford's engine modules with integrated transmission control do not use P0700. Any limp mode comes from the transmission fault, not from P0700.

Written from public technical sources and not yet checked by a mechanic. How we write these pages

Symptoms

  • Check engine light, possibly transmission warning
  • Depending on the transmission fault: limp mode, harsh or delayed shifts
  • Often no symptoms if the fault was intermittent
  • Simple OBD reader shows only P0700

Common causes

  1. Actual fault stored in the transmission module (sensor, solenoid, ratio, speed sensor) Most likely
  2. Wrong transmission fluid level or condition causing slip or ratio codes Possible
  3. Harness or connector at the transmission corroded or damaged Possible
  4. Low system voltage or weak battery Less likely
  5. Transmission module or software faulty Less likely

How to diagnose P0700

  1. Read the transmission module codes. Basic code readers can't, so use a scanner that supports your transmission, or ask an auto parts store or shop.
  2. Check the transmission fluid level and condition. Dark, burnt-smelling fluid is a warning sign.
  3. Check battery voltage. Low voltage can make the transmission module set false codes.
  4. Repair according to the specific transmission code, such as a speed sensor, shift solenoid or wiring.

Vehicles that report P0700 most

VehicleYearsReportsMedian miles
Chevrolet Silverado 15002015–20243081k
GMC Sierra 15002014–20251687k
GMC Acadia2007–20211294k
Chevrolet Equinox2005–20131175k
Chevrolet Malibu2010–2023952k
Suzuki Forenza2005–2008887k
Chevrolet Tahoe2017–20227—
Jeep Grand Cherokee2004–2006670k
Chevrolet Traverse2013–20236—
Chevrolet Suburban2015–20236—

Counts of owner complaints to the NHTSA that mention P0700 (275 in total), not failure rates: popular models get more complaints simply because more of them are on the road. Models with fewer than 3 complaints are left out.

Reading the code

P
Powertrain
0
Generic (SAE) code
7
Transmission
00
Specific fault

Questions drivers ask

Can I drive with code P0700?

It depends on the real fault. If the transmission is stuck in one gear or shifting harshly, drive only to a shop. If it shifts normally, get it scanned soon.

Will my car pass an emissions inspection with P0700?

Probably not in states that test vehicles with an OBD-II scan: an emissions-related code that keeps the check engine light on is usually an automatic fail. Rules differ by state and county, so check yours.

Often reported together

Codes that owners mention in the same NHTSA complaints as P0700. They can point to a shared cause, so it's worth checking them together.

This page is general information, not a substitute for a professional diagnosis. Repair costs are rough estimates for parts and labor and vary by vehicle and region.