Powertrain, generic · Transmission

P0798 Pressure Control Solenoid C Electrical

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modePossible

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.

Likely causes

Clutch valve SLC2 coil faulty
Wire or connector open or shorted
Transmission module damaged (e.g. after a short)

Symptoms

  • Limp mode (second gear and reverse only)
  • Harsh shifts
  • Transmission warning or check engine light

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€150–1,500
Time1–5 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

pressure control solenoidtransmission valve bodytransmission clutchestransmission control module

Related codes

P0796P0799P0969P0970P0971P0778

References: saabwisonline.com, law.cornell.edu.