A/T - Resistance Test For Shift Solenoids

91chevy01

Number: 91-124-7A


Section: 7A


Date: November 1990


Corporate Bulletin No.: 077146


Subject: SOLENOID(S) RESISTANCE TEST FOR SHIFT SOLENOIDS - A AND B, TCC SOLENOID, TCC PWM SOLENOID


Model and Year: 1991 LUMINA WITH 4T60-E AUTOMATIC TRANSMISSION


TO: ALL CHEVROLET DEALERS

BULLETIN COVERS:


Resistance test values of solenoids on a vehicle equipped with a HYDRA-MATIC 4T60-E transaxle.

2.4L DOHC ELECTRICAL CIRCUIT:

4.9L PFI & 3800 TPI (RPO L27/VINL) ELECTRICAL CIRCUIT:

SERVICE PROCEDURE: (Figure 1)


Reference the resistance values below when testing solenoids with the Transaxle Test Box J 38791, following all instructions and notices included with the tool.

RESISTANCE RESISTANCE

@ 20 degrees C. @ 88 degrees C.

SOLENOID (68 degrees F.) (190 degrees F.)

Shift Solenoids A and B *20-30 Ohms *23-50 Ohms

TCC ([1][2]Torque Converter Clutch) *20-30 Ohms *23-50 Ohms

Solenoid

TCC PWM (Pulse Width Modulated) *10-15 Ohms *11-25 Ohms
(1991 Twin DOHC 3.4L HYDRA-MATIC 4T60-E W-car models do not have a PWM solenoid)

* These resistance values are measured at specified temperatures, and the resistance values could be greater at higher temperatures and reduced at lower temperatures.

SERVICE MANUAL REFERENCE:

Refer to 1991 Service Manual On-Car section for proper disassembly and assembly procedures.


SERVICE NOTES:


NOTICE: If energizing the TCC solenoid without using the Transaxle Test Box J 38791, ensure that the positive lead is connected to the "A" terminal and the negative lead to the "D" terminal. If the leads are reversed, the TCC solenoid diode will be damaged by the reverse polarity. A damaged TCC diode will allow the brake switch to be damaged by high voltage arcing, when the brake switch is depressed.