When the gear selector lever is moved to the DRIVE Range (D) position from the NEUTRAL (N) position, the following hydraulic and electrical system changes occur to shift the transmission into Drive Range - First Gear.

In the DRIVE position, the manual valve routes line (2) pressure into the drive (19) fluid circuit. Drive (19) fluid is routed to the neutral relay valve, the C1 control valve, the B1 control valve, the reverse shift ball check valve (#6), the B2 control valve, the U1 shift valve, the U2 shift valve, the 2-3, 3-4 shift solenoid valve assembly (S2), and the 1-2, 2-3, reverse shift solenoid valve assembly (S3).

C1 Control Valve

Drive (19) fluid pressure is regulated through the C1 control valve into the forward clutch (26) fluid circuit.

Neutral Relay Valve

Drive (19) fluid pressure also passes through the neutral relay valve into the forward clutch (26) fluid circuit.

#12 Ball Check Valve

Located in the front control valve body assembly, drive (19) fluid pressure seats the #12 ball check valve against the forward clutch fluid passage.

#8 Accumulator Check Valve Assembly

Forward clutch (26) fluid pressure is routed to the #8 accumulator check valve assembly and moves the check valve against spring force in order to help cushion the apply of the forward clutch.

Forward Clutch (C1) Assembly

Forward clutch (26) fluid is routed to the forward clutch piston to apply the forward clutch plates.

Forward Clutch (C1) Accumulator

Forward clutch (26) fluid is also directed to the forward clutch accumulator assembly. Forward clutch (26) fluid pressure moves the forward clutch accumulator piston against spring force to cushion the apply of the forward clutch.

Reverse, 1st Shift Solenoid (SS) Valve Assembly (S1)

The reverse, 1st SS valve assembly is energized, causing fluid pressure to build-up in the S1 signal (14) fluid circuit.

U1 Shift Valve

S1 signal (14) fluid is routed to the U1 shift valve and passes through the valve into the reverse inhibit (52) fluid circuit.

M1 Shift Valve

Reverse inhibit (52) fluid is routed to the M1 shift valve and applies the valve against spring force.

B2 Control Valve

Drive (19) fluid pressure is regulated through the B2 control valve into the B2 control 1 (30) fluid circuit. B2 control 1 (30) fluid pressure is routed through the U1 shift valve into the B2 control 2 (31) fluid circuit and on to the M1 shift valve where it is blocked by the valve in preparation for an upshift to second gear.

#6 Reverse Shift Ball Check Valve

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

Shift Pressure Control Valve

The shift pressure control valve regulates drive or reverse (20) fluid pressure into the regulated drive or reverse (21) fluid circuit. Regulated drive or reverse fluid (21) is routed to shift pressure relay valve, enters the B1 control 2 (34) fluid circuit and continues on to the M1 shift valve where it is blocked by the valve in preparation for an upshift to second gear.

Important: Power flow for Intermediate Range - First Gear is exactly the same as Drive Range - First Gear.

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