P0989 code meaning
Transmission Fluid Pressure Sensor/Switch E Circuit Low
What P0989 means
Pressure switch E reads low, meaning no pressure, when it should show pressure. GM's 6T70/6T75 family uses E for switch 5 on the R1/4-5-6 clutch regulator valve; the normally closed switch sees pressure while both the low/reverse and the 4-5-6 clutch are released. The module counts clutch releases after which the signal stays low, checked with commanded clutch pressure at 50 kPa or less: 18 counts in GM's 2011 tables and on the Saab 9-4X, 17 in the 2016 table. It is a Type C or Special No Trip code without MIL, and the adaptations of both clutches are frozen. Sonnax lists P0989 among typical switch failures in this valve body module. P0990 is the stuck-high counterpart; switches A to D use P0840 to P0878.
P0989 at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modePossible
- Repair difficultyHard
- Typical labor1.5 to 5 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P0989
- No warning light, code stored only
- Shifts into 4th to 6th or reverse gradually less smooth
- Occasional limp mode if the fault persists
Common causes of P0989
- Most likelyDamaged or delaminated film in switch 5 of the valve body module
- PossibleDebris keeping pressure away from the switch
- PossibleR1/4-5-6 clutch regulator valve sticking
- Less likelyLow fluid level
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Tfp sensor eWiring harnessTCM
What each part of P0989 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 9 | Area: transmission. |
| 89 | The exact fault in that area. |
What to do next
- Note P0989 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 P0989
What does P0989 mean?
P0989 means "Transmission Fluid Pressure Sensor/Switch E Circuit Low". Pressure switch E reads low, meaning no pressure, when it should show pressure. It is a generic code, so it means the same on every make.
Is it safe to drive with P0989?
Drive gently and only to a workshop. With P0989 the car can go into limp mode (reduced power) to protect itself.
Will P0989 fail an emissions test?
P0989 is not an emissions code, so on its own it usually does not fail an emissions test. Other stored codes or a lit check engine light still can.
How hard is P0989 to fix?
Difficulty: hard. A typical repair takes 1.5 to 5 hours of work. This is a job for a workshop.
Will P0989 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.