A/T - DTC 37 Erroneously Set in TCM Memory

BULLETIN NUMBER
SB93-05-020

ISSUE DATE
November 1993

GROUP
TRANSMISSION

TECH-1 USAGE (4L30-E A/T CODE 37)

AFFECTED VEHICLES

1994 Trooper (UX) and Rodeo (UC) models equipped with automatic transmission.

SERVICE INFORMATION

On affected vehicles, when connecting the Tech-1 scan tool to the ALDL connector, a "no fault" diagnostic trouble code 37 may be set in the transmission control module (TCM). This may occur due to interruption of the serial data transfer when connecting the Tech-1 between the TCM and ECM. In this condition situation, code 37 does not indicate a failure and does not require further diagnosis or repair. Clear the code from TCM memory as described in the appropriate Workshop Manual. Then continue with Tech-1 diagnostics for other trouble codes set in the TCM.

A failure of the A/T torque management ALDL circuit will also set code 37. In this situation, an actual failure of the torque management circuit is indicated, and A/T will be in backup mode (manual shifting only). In this condition, refer to the appropriate Workshop Manual for A/T diagnostic procedures for code 37.