A/T - Cold Delay Shift

NO.
TSB-92-23-006 Revision

DATE
November, 1992


MODEL
1992-93 Diamante,
1992-93 Expo, Expo LRV,
1992-93 3000GT



SUBJECT:

COLD DELAY SHIFT



This bulletin supersedes TSB-92-23-006, dated August 1992, which should be discarded. The revisions include: models affected, the computer and sensor involved in upshift delay, addition of temperature specification, and deletes reference to the owners manual.

PURPOSE

This bulletin describes the 1992-93 Diamante, 1992-93 Expo/Expo LRV, and 1992-93 3000 GT automatic transaxle operation during "cold" vehicle starts and "cold" operation. The Transaxle Control Module (TCM) is programmed to delay up-shifts (shift points) for approximately 2 minutes after the vehicle is started "cold". Delaying up-shifts allows the engine and catalytic converter to warm up faster thereby lowering emissions during "cold" operation.

If you should encounter a customer who complains "The trans does not shift at the same speeds when "cold" as it does warm." please explain to the customer the purpose of the delayed up-shift, and that is a normal operating characteristic of the transaxle.

DETAILS

Every time the engine is started, the TCM checks the Automatic Transaxle Fluid Oil Temperature Sensor information. If the sensor indicates a "cold" transaxle (below 350 C (95~F)), the TCM is programmed to delay the transaxle's up-shift points for a period of approximately 2 minutes. After approximately 2 minutes, the Transaxle's shift points will return to normal.