P0727 code meaning
Engine Speed Input Circuit No Signal
Powertrain system Generic code P07xx codes Check engine light
What P0727 means
The transmission module needs engine speed for converter slip, shift quality and to check the turbine speed. Today it almost always arrives over CAN from the engine module with a validity flag; only GM's 2007 Allison 1000 tables show a separate engine speed sensor read by the transmission module. P0727 means the engine speed signal is missing although the transmission is turning. The Allison 1000 flags under 61 rpm for 4 s with turbine speed of 400 rpm or more, after two trips; Saab's 9-3 of 2000 input speed above 2000 rpm for more than 5 s without engine speed; a 2006 GM table the CAN engine speed failing to answer. The module then works without converter slip information, usually locks out the converter clutch and may enter limp mode.
P0727 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyMedium, DIY possible
- Typical labor0.5 to 2 hours
- Clears after repairAfter a drive cycle
Symptoms of P0727
- Transmission warning lamp, possibly check engine light
- Torque converter clutch locked out
- Harsh shifts or limp mode
- Often an engine code (crankshaft sensor) as well
Common causes of P0727
- Most likelyEngine speed wire or connector open, or own sensor (Allison) faulty
- PossibleCAN communication between engine and transmission module disturbed
- PossibleCrankshaft sensor fault in the engine module
- Less likelyTransmission module faulty
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Engine speed signalCAN busTransmission control module
What each part of P0727 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 7 | Area: transmission. |
| 27 | The exact fault in that area. |
What to do next
- Note P0727 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P0727
What does P0727 mean?
P0727 means "Engine Speed Input Circuit No Signal". The transmission module needs engine speed for converter slip, shift quality and to check the turbine speed. It is a generic code, so it means the same on every make.
Is it safe to drive with P0727?
Drive gently and only to a workshop. With P0727 the car can go into limp mode (reduced power) to protect itself.
Will P0727 fail an emissions test?
Yes, it can. P0727 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P0727 to fix?
Difficulty: medium. A typical repair takes 0.5 to 2 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will P0727 clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.