Powertrain, generic · Transmission

P0796 Pressure Control Solenoid C Performance/Stuck Off

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
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. P0796 means valve C is electrically fine but pressure stays too low. GM's 6-speed flags 400 rpm slip in steady fourth gear with an intrusive test (4-5-6 clutch), the 8-speed 400 rpm for 1.5 s three times (clutch 3), the 9-speed clutch 3 slip over 200 rpm for 3 s, the CVT a line pressure deviation – all after one trip. GM noted false settings on 2017 8-speeds; a 9-speed bulletin calls for clutch inspection and a new valve body. Slipping, missing upper gears and limp mode follow.

Likely causes

Clutch, return spring or piston seal of the assigned clutch faulty
Valve body or pressure valve dirty or worn
Fluid level low, fluid worn, filter clogged
Software false setting

Symptoms

  • Slipping or missing upper gears
  • Limp mode
  • Check engine light

Repair estimate

DifficultyHardWorkshop job
Parts and labour€300–5,000
Time1–14 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

P0795P0797P0798P0776P0746P0969

References: gsi.ext.gm.com, gsi.ext.gm.com, gsi.ext.gm.com, gsi.ext.gm.com.