Safety Warning
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Hydraulic Circuit Identification and Function
2005 Ford Taurus SEL, 4D SedanSECTION Hydraulic Circuit Identification and Function
WARNING: This page is about a different car, the 2010 Mercury Milan and 2010 Ford Fusion. However, it is still accessible from the selected car via links, so may be relevant.
Hydraulic Circuit Identification Chart
HYDRAULIC CIRCUIT IDENTIFICATION CHART
| Circuit Name | Description |
|---|---|
| BYPASS | Pressure from the main pressure regulator valve to the pump assembly suction circuit for line pressure control. |
| C1234 | Regulated line pressure from the 1234 regulator valve supplied to the forward (1, 2, 3, 4) clutch to apply the clutch. |
| C1234 FDBK | C1234 pressure from the 1234 latch valve supplied to the 1234 regulator valve to oppose movement of the valve from VBS C1234 pressure during forward (1, 2, 3, 4) clutch application. |
| C35R | Regulated line pressure from the 35R regulator valve supplied to the direct (3, 5, R) clutch to apply the clutch. |
| C35R FD | Line pressure from the REVERSE circuit supplied to the DRIVE 2/C35R FD shuttle valve by the clutch control bypass valve to supply the 35R regulator valve with line pressure in reverse. |
| C35R FDBK | C35R pressure from the 35R latch valve supplied to the 35R regulator valve to oppose movement of the valve from VBS C35R pressure during direct (3, 5, R) clutch application. |
| C456 | Regulated line pressure from the low reverse/456 regulator valve directed to the Overdrive (O/D) (4, 5, 6) clutch by the clutch control bypass valve. C456 also provides latch pressure for the clutch control bypass valve. |
| CB26 | Regulated line pressure from the 26 regulator valve to the intermediate (2, 6) clutch to apply the clutch in 2nd and 6th gears. |
| CB26 FDBK | CB26 pressure from the 26 latch valve supplied to the 26 regulator valve to oppose movement of the valve from VBS C26 pressure during intermediate (2, 6) clutch application. |
| CBR1 | Regulated line pressure from the low reverse/456 regulator valve directed to the low/reverse clutch by the clutch control bypass valve. |
| CBR1/C456 | Regulated line pressure from the low reverse/456 regulator valve to the clutch control bypass valve. |
| CBR1/C456 FDBK | CBR1/C456 pressure from the low reverse/456 latch valve supplied to the low reverse/456 regulator valve to oppose movement of the valve from VBS CBR1/456 pressure during low/reverse or O/D (4, 5, 6) clutch application. |
| COMP FD | Pressure supplied to the opposite side of the O/D (4, 5, 6) and direct (3, 5, R) clutch apply pistons to oppose centrifugal application of the clutches. |
| CONV FD | Line pressure from the main pressure regulator valve supplied to the Torque Converter Clutch (TCC) control valve for TCC release. |
| COOLER FD | Return pressure from the torque converter during TCC release that is directed to the transmission fluid cooler by the TCC control valve. |
| DRIVE | Line pressure directed to the clutch control bypass valve, 1234 regulator valve and the 26 regulator valve by the manual valve in the DRIVE position. |
| DRIVE 2 | DRIVE pressure directed to the TCC regulator valve and the DRIVE 2/C35R FD shuttle valve by the clutch control bypass valve to supply the 35R regulator valve with line pressure in 3rd and 5th gears. |
| DRIVE 2/C35R FD | DRIVE 2 or C35R FD pressure supplied to the 35R regulator valve from the DRIVE 2/C35R FD shuttle valve during direct (3, 5, R) clutch application. |
| EXH | Fluid exhausted from the valves that drains to the sump area. |
| EXH BF | Unpressurized fluid from the manual valve that fills the unused hydraulic circuits. |
| LINE | Pressure from the pump to the control pressure regulator, solenoid regulator valve, manual valve and low reverse/456 regulator valve. Line pressure is regulated by the main pressure regulator valve. |
| LUBE | Transaxle lubrication circuit (through the input shaft) |
| ON/OFF SIG | Full solenoid output pressure from Shift Solenoid E (SSE) to the clutch control bypass valve and the TCC regulator valve. ON/OFF SIG pressure positions the clutch control bypass valve to apply either the low/reverse clutch or the O/D (4, 5, 6) clutch. |
| REG APPLY | Regulated DRIVE 2 pressure supplied to the TCC control valve by the control pressure regulator for TCC application. |
| REVERSE | Line pressure directed to the clutch control bypass valve by the manual valve in the REVERSE position. |
| SOL FD | Regulated line pressure supplied to the shift, TCC and Line Pressure Control (LPC) solenoids. |
| TCC APPLY | Pressure supplied to the torque converter by the TCC control valve to apply the clutch. TCC APPLY is also the return circuit for the TCC RELEASE circuit. |
| TCC RELEASE | Pressure supplied to the torque converter by the TCC control valve to release the clutch. TCC RELEASE is also the return circuit for the TCC APPLY circuit. |
| VBS C1234 | Variable SOL FD pressure supplied to the 1234 regulator valve and 1234 latch valve by Shift Solenoid A (SSA) to position the valves to apply the forward (1, 2, 3, 4) clutch. |
| VBS C35R | Variable SOL FD pressure supplied to the 35R regulator valve and 35R latch valve by Shift Solenoid B (SSB) to position the valves to apply the direct (3, 5, R) clutch. |
| VBS CB26 | Variable SOL FD pressure supplied to the 26 regulator valve and 26 latch valve by Shift Solenoid C (SSC) to position the valves to apply the intermediate (2, 6) clutch. |
| VBS CBR1/456 | Variable SOL FD pressure supplied to the low reverse/456 regulator valve and low reverse/456 latch valve by Shift Solenoid D (SSD) to position the valves to apply the low/reverse clutch or O/D (4, 5, 6) clutch. |
| VBS LINE | Variable SOL FD pressure supplied to the main pressure regulator valve by the LPC solenoid to control line pressure. |
| VBS TCC | Variable SOL FD pressure supplied to the TCC regulator valve and TCC control valve to position the valves by the TCC solenoid to apply the TCC . |
RENDER: 1.0x
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.