GM Service Manual Online
For 1990-2009 cars only

When the gear selector lever is moved to the REVERSE (R) position (from the PARK position) the following changes occur in the transmission's hydraulic and electrical systems.

PRESSURE REGULATION

Manual Valve

With the manual valve in the REVERSE position, line (2) pressure is directed into the reverse (22) fluid circuit.

Primary Pressure Regulator Valve

Reverse (22) fluid pressure, at the primary regulator valve plunger, boosts line (2) pressure for the additional torque requirements in REVERSE. Throttle signal (10) fluid pressure from the line pressure control solenoid valve (SLT) acting on the primary regulator valve plunger also helps determine line (2) pressure in REVERSE depending on throttle position and other TCM input signals.

LOW AND REVERSE CLUTCH (B3) ASSEMBLY APPLIES

#7 Accumulator Check Valve Assembly

Reverse (22) fluid pressure is routed to the #7 accumulator check valve assembly where it passes into the reverse clutch (23) circuit. Reverse (22) fluid pressure moves the check valve against spring force in order to cushion the apply of the low and reverse clutch.

M1 Shift Valve

Reverse clutch (23) fluid passes through the M1 shift valve into the low and reverse clutch (24) fluid circuit.

Low and Reverse Clutch (B3) Assembly

Low and reverse clutch (24) fluid is routed to the low and reverse clutch piston to apply the low and reverse clutch plates.

DIRECT CLUTCH (C2) ASSEMBLY APPLIES

Reverse Shift Solenoid (SS) Valve Assembly (S5)

The normally closed reverse SS valve assembly is energized, allowing fluid pressure in the S5 signal (18) fluid circuit to exhaust through the solenoid.

#6 Reverse Shift Ball Check Valve

Reverse (22) fluid seats the reverse shift ball check valve against the drive (19) fluid passage and enters the drive or reverse (20) fluid passage.

Shift Pressure Relay Valve

S5 signal (18) fluid is exhausted from the shift pressure relay valve and spring force moves the valve to the released position to allow drive or reverse (20) fluid to enter the direct clutch feed 1 (27) fluid circuit.

M1 Shift Valve

Direct clutch feed 1 (27) fluid passes through the M1 shift valve into the direct clutch feed 2 (28) fluid circuit.

M2 Shift Valve

Direct clutch feed 2 (28) fluid passes through the M2 shift valve into the direct clutch (29) fluid circuit.

#1 Accumulator Check Valve Assembly

Direct clutch (29) fluid pressure is routed to the #1 accumulator check valve assembly and moves the check valve against spring force in order to cushion the apply of the direct clutch.

Direct Clutch (C2) Assembly

Direct clutch (29) fluid is routed to the direct clutch piston to apply the direct clutch plates.

1-2, 2-3, Reverse Shift Solenoid (SS) Valve Assembly (S3)

The normally closed 1-2, 2-3, reverse SS valve assembly is energized. However, because there is no fluid supplied to the circuit, the 1-2, 2-3, reverse SS valve assembly has no effect in REVERSE.

PASSAGES

  1. SUCTION
  2. LINE
  3. CONVERTER FEED
  4. RELEASE
  5. APPLY
  6. EXHAUST ENABLE
  7. COOLER
  8. LUBE
  9. SOLENOID MODULATOR
  10. THROTTLE SIGNAL (SLT)
  11. SHIFT CONTROL (SLS)
  12. LOCK UP CONTROL (SLU)
  13. TCC SIGNAL
  14. S1 SIGNAL
  15. S2 SIGNAL
  16. S3 SIGNAL
  17. S4 SIGNAL
  18. S5 SIGNAL
  19. DRIVE
  20. DRIVE OR REVERSE
  21. REGULATED DRIVE OR REVERSE
  22. REVERSE
  23. REVERSE CLUTCH
  24. LOW AND REVERSE CLUTCH
  25. REVERSE CONTROL
  26. FORWARD CLUTCH
  27. DIRECT CLUTCH FEED 1
  28. DIRECT CLUTCH FEED 2
  29. DIRECT CLUTCH
  30. B2 CONTROL 1
  31. B2 CONTROL 2
  32. SECOND CLUTCH
  33. B1 CONTROL 1
  34. B1 CONTROL 2
  35. B1 CONTROL 3
  36. SECOND COAST CLUTCH
  37. B5 CONTROL 1
  38. B5 CONTROL 2
  39. 1-2 REVERSE (B5) CLUTCH
  40. 4-5 CLUTCH
  41. B4 CONTROL
  42. B4 RELEASE
  43. SERVO RELEASE
  44. SERVO FEED
  45. SERVO APPLY
  46. 3RD GEAR BAND APPLY
  47. PN12345
  48. PRN15
  49. 234NCON
  50. 345 ENABLE
  51. 45 ENABLE
  52. REVERSE INHIBIT
  53. VENT
  54. EXHAUST
  55. SUMP
  56. VOID
  57. TORQUE CONVERTER SEAL DRAINBACK

Reverse


Object Number: 824518  Size: FS