A/T - 4L80-E/4L80-EHD Service Manual Updates

BULLETIN NO.: 9174L80-E-02

CORP. REF. NO.: 177107R

DATE: Feb., 1991

TRANSMISSION APPLICATIONS:
1991 HYDRA-MATIC 4L80-E/4L80-EHD
(MT1)

TRANSMISSION MODELS:
All Models

SUBJECT:
SERVICE MANUAL UPDATES
(Section 7A Transmission Diagnosis Charts Updated)

VEHICLE APPLICATIONS:
1991 C, K AND P-Trucks G-Van R and V Trucks

Bulletin Covers:

HYDRA-MATIC 4L80-E EHD Transmission updates occuring after Service Manual printing.

LIGHT DUTY TRUCK SERVICE MANUAL UPDATES:




Automatic Transmission/Diagnosis Information.
Range Reference Chart has been revised. (Figure 1)




Wiring Diagram has been revised. (Figure 2)

Remove notice under Torque Converter Clutch (TCC) Diagnosis:

NOTICE SAYS: Do not bench test the TCC Solenoid Using an automotive type battery. Accidentally crossed wires will damage the internal diode of the Solenoid.

(This notice does not apply to the 4L80-E Transmission)