Oil Pressure Switch - Information: Overview
Number: REISSUE 83-96Section: 7A (VIIc)
Date: Dec., 1983
Subject: OIL PRESSURE SWITCH INFORMATION
Model and Year: ALL THM 700-R4
TO: ALL CHEVROLET DEALERS
This bulletin is reissued to cover part number changes, part number identification color code revisions, and graphic illustration revisions. Bulletin 83-96 dated October, 1983 should be destroyed.
FIGURE 1 - FOUR SWITCH LOCATIONS:
The THM 700-R4 transmission has four (4) oil pressure switch locations in the control valve assembly (see Figure 1).
Depending on vehicle type, various oil pressure switches will be used in these locations. When no switch is used, a 1/8 inch NPT pipe plug, P/N 444612, is installed in place of the switch.
On vehicles built without an electronic control module (ECM) these switches control the torque converter clutch
operation and exhaust gas recirculation (EGR) bleed system. On ECM equipped vehicles these switches help supply information to the ECM about the transmission operation. The ECM also controls various functions including fuel mixture, engine timing, engine idle, and torque converter clutch (TCC) operation. If switches are wrong, mislocated, or malfunction, various electrical and mechanical problems may result, i.e., blown fuses, instrument panel lights remaining on without apparent reason, or improper engine operation.