Transmission Temperature Sensor

Transmission Temperature Sensor

The temperature of the Automatic Transmission Fluid (ATF) is measured by the Negative Temperature Coefficient (NTC) transmission temperature sensor. The EAT ECU (C1835) provides a feed to the temperature sensor (C0244) on a BR wire. By measuring the voltage returned on a WR wire, the EAT ECU can determine ATF temperature.

Inhibitor Switch

The inhibitor switch is mounted on the LH side of the transmission, and enables the EAT ECU to monitor the position of the manual selector spool valve and the selected drive program. The EAT ECU (C1835) provides an ignition feed to the inhibitor switch (C0244) on a YB wire. When Park or Neutral is selected, the inhibitor switch (C0244) returns a feed back to the EAT ECU (C1835) on an O wire. When Drive is selected, the inhibitor switch (C0244) returns a feed back to the EAT ECU (C1835) on a B wire.

When shift solenoid A is energised, the inhibitor switch (C0244) returns a feed back to the EAT ECU (C1835) on a PW wire. When shift solenoid B is energised, the inhibitor switch (C0244) returns a feed back to the EAT ECU (C1835) on a YB wire. When shift solenoid C is energised, the inhibitor switch (C0244) returns a feed back to the EAT ECU (C1835) on a TB wire.

NOTE: Wire colour TB is transparent with a black tracer.

Shift Interlock Solenoid

To lock the selector lever assembly, the EAT ECU (C0193) provides a feed to the shift interlock solenoid (C0673) on a BP wire. An earth path is provided by the EAT ECU (C0193) on an NP wire.

Steptronic

When manual (Steptronic) mode is selected, the EAT ECU selects gears according to inputs received from the Steptronic switch. The EAT ECU (C0193) provides two feeds to the Steptronic switch (C1664); one on a UY wire, one on a US wire. If a downshift is requested via the selector lever, a momentary earth is created. Current on the UY wire is allowed to flow across the switch to earth on an NB wire. Sensing this, the EAT ECU downshifts 1 gear.

If an upshift is requested via the selector lever, a momentary earth is created. Current on the US wire is now allowed to flow across the switch to earth on an NB wire. Sensing this, the EAT ECU upshifts 1 gear.