GM Service Manual Online
For 1990-2009 cars only

When the gear selector lever is moved to the NEUTRAL (N) position, the hydraulic and electrical system operation is identical to PARK (P) range. However, if NEUTRAL is selected after the vehicle was operating in REVERSE (R), the following changes would occur in the hydraulic system.

LOW AND REVERSE CLUTCH RELEASES

Manual Valve

The manual valve is moved to the NEUTRAL position and blocks line (2) pressure from entering the reverse (22) fluid circuit. The reverse (22) fluid circuit is opened to an exhaust at the manual valve.

Low and Reverse Clutch (B3) Assembly

Low and reverse clutch (24) fluid exhausts from the low and reverse clutch assembly allowing the low and reverse clutch to release.

M1 Shift Valve

Exhausting low and reverse clutch (24) fluid is routed into the reverse clutch (23) circuit at the M1 shift valve, the reverse (22) circuit at the #7 accumulator check valve assembly, and on to the manual valve where it exhausts.

Primary Pressure Regulator Valve

Reverse (22) fluid pressure also exhausts from the primary regulator valve plunger, allowing line (2) pressure to return to the normal operating range as in PARK, NEUTRAL and DRIVE gear ranges.

DIRECT CLUTCH (C2) ASSEMBLY RELEASES

Reverse Shift Solenoid (SS) Valve Assembly (S5)

The reverse SS valve assembly is de-energized, causing fluid pressure to build-up in the S5 signal (18) fluid circuit.

Shift Pressure Relay Valve

S5 signal (18) fluid is routed to the shift pressure relay valve and applies the valve against spring force.

Direct Clutch (C2) Assembly

Direct clutch (29) fluid exhausts from direct clutch assembly to the M2 shift valve allowing the direct clutch assembly to release.

M2 Shift Valve

Exhausting direct clutch (29) fluid passes through the M2 shift valve into the direct clutch feed 2 (28) fluid circuit and on to the M1 shift valve.

M1 Shift Valve

At the M1 shift valve exhausting direct clutch fluid passes from the direct clutch feed 2 (28) fluid circuit into the direct clutch feed 1 (27) fluid circuit and continues on to the shift pressure relay valve.

Shift Pressure Relay Valve

Exhausting direct clutch feed 1 (27) fluid passes through the shift pressure relay valve and enters the regulated drive or reverse (21) circuit.

Shift Pressure Control Valve

Exhausting regulated drive or reverse  (21) fluid passes through the shift pressure control valve and enters the drive or reverse (20) circuit.

#6 Reverse Shift Ball Check Valve

Exhausting drive or reverse (20) fluid seats the reverse shift ball check valve against the drive (19) fluid passage, enters the reverse (22) fluid passage and continues on to an exhaust at the manual valve.

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

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

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

Neutral - Engine Running


Object Number: 824521  Size: FS