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Home >> Chrysler >> 2011 >> 300 C, 4WD >> Repair and Diagnosis >> External Pages >> Different car >> Section 853 (DTCS P0871 To U1449 - 65RFE Automatic Transmission - 1500) >> Diagnosis And Testing >> P0988-4C Pressure Switch Rationality >> Theory Of Operation

Theory Of Operation

WARNING: This page is about a different car, the 2015 RAM 1500. However, it is still accessible from the selected car via links, so may be relevant.

The Transmission System uses five pressure switches to monitor the fluid pressure in the L/R, 2C, 4C, UD and OD clutch circuits. The pressure switches are continuously monitored for the correct states in each gear as shown in the PRESSURE SWITCH VS GEAR TABLE .

PRESSURE SWITCH VS GEAR TABLE

GEAR L/R 2C 4C UD OD
REVERSE  OPEN OPEN OPEN OPEN OPEN
P/N  CLOSED** OPEN OPEN OPEN OPEN
1ST  CLOSED* OPEN OPEN CLOSED OPEN
2ND  OPEN CLOSED OPEN CLOSED OPEN
2ND PRIME  OPEN OPEN CLOSED CLOSED OPEN
3RD  OPEN OPEN OPEN CLOSED CLOSED
4TH  OPEN OPEN CLOSED OPEN CLOSED
5TH  OPEN CLOSED OPEN OPEN CLOSED
*L/R is closed if output speed is below 100 RPM in Drive and Manual 2. L/R is closed in Manual 1.
**May be open when rolling in Neutral or at low oil temperatures.