P0798 code meaning
Pressure Control Solenoid C Electrical
Powertrain system Generic code P07xx codes Check engine light
What P0798 means
Pressure control solenoids are current-controlled proportional valves, and what B and C mean depends on the design: on GM's clutch-to-clutch automatics they are the pressure valves of clutches 2 and 3, on GM's CVT B is primary pulley pressure and C line pressure, on Jatco CVTs B is the secondary pressure valve, on Saab's AF40 B and C are clutch valves SLC1/SLC2. P0798 is the electrical code for valve C. Only Saab's 9-5 (2010–11) with Aisin AF40 uses it: a deviation between commanded and feedback current of clutch valve SLC2 (normal range 0.1–1.1 A), with the circuit codes P0969–P0971 alongside, rated after two trips. The module switches all solenoids off and keeps only second gear and reverse, without adaption. GM and Ford use the circuit codes P0968–P0971 instead.
P0798 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyMedium
- Typical labor1 to 5 hours
- Clears after repairAfter a drive cycle
Symptoms of P0798
- Limp mode (second gear and reverse only)
- Harsh shifts
- Transmission warning or check engine light
Common causes of P0798
- Most likelyClutch valve SLC2 coil faulty
- PossibleWire or connector open or shorted
- Less likelyTransmission module damaged (e.g. after a short)
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Pressure control solenoidTransmission valve bodyTransmission clutchesTransmission control module
What each part of P0798 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. |
| 98 | The exact fault in that area. |
What to do next
- Note P0798 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 P0798
What does P0798 mean?
P0798 means "Pressure Control Solenoid C Electrical". Pressure control solenoids are current-controlled proportional valves, and what B and C mean depends on the design: on GM's clutch-to-clutch automatics they are the pressure valves of clutches 2 and 3, on GM's CVT B is primary pulley pressure and C line pressure, on Jatco CVTs B is the secondary pressure valve, on Saab's AF40 B and C are clutch valves SLC1/SLC2. It is a generic code, so it means the same on every make.
Is it safe to drive with P0798?
Drive gently and only to a workshop. With P0798 the car can go into limp mode (reduced power) to protect itself.
Will P0798 fail an emissions test?
Yes, it can. P0798 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 P0798 to fix?
Difficulty: medium. A typical repair takes 1 to 5 hours of work. This is a job for a workshop.
Will P0798 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.