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Home >> Porsche >> 2000 >> Boxster Base, Automatic >> Repair and Diagnosis >> Transmission >> Automatic Trans >> Automatic Transmission Controls, Case - Diagnosis >> Tiptronic diagnosis >> Fault overview >> Test point 7 >> Possible causes, elimination, notes

Possible causes, elimination, notes

If there is a short to B+ on pressure regulator 4, the torque converter clutch will always stay open.

NOTE: The pressure regulators (DRs) are pressure-control solenoid valves. They convert an electrical current to a proportional hydraulic pressure.
  1. Check pressure regulator with wiring. To do this, connect an ohmmeter to the control module connector and measure the resistance:
    1. DR1 = Pin 52 and pin 5
    2. DR2 = Pin 52 and pin 1
    3. DR3 = Pin 52 and pin 29
    4. DR4 = Pin 52 and pin 4

    Nominal value: 5 ... 10 ohm

  2. Check wiring from the control module connector pins 1, 4, 5 and 29 to the 16-pole transmission connector pins 3, 11, 2 and 7 for continuity, short to ground and short to B+.
  3. Check the pressure regulator. To do this, remove the ATF pan, pull off plug connection on the pressure regulator and measure the resistance.

    Nominal value: 5-10 ohm

NOTE: The hydraulic control unit must be removed before the DR4 (modulation pressure) can be tested.
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