Flash: 845RE Transmission Shift Enhancements

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NUMBER: 21-036-16
GROUP: Transmission and Transfer Case
DATE: November 19, 2016

THIS BULLETIN SUPERSEDES SERVICE BULLETIN 21-025-15 REV. A, DATED AUGUST 05, 2015, WHICH SHOULD BE REMOVED FROM YOUR FILES. ALL REVISIONS ARE HIGHLIGHTED WITH **ASTERISKS** AND INCLUDE ADDITION OF IMPROVEMENT AND LABOR OP.

FOR HELP WITH USING wiTECH FOR ECU FLASH REPROGRAMMING, CLICK ON THE APPLICATION’S “HELP” TAB.

THE wiTECH SOFTWARE IS REQUIRED TO BE AT THE LATEST RELEASE BEFORE PERFORMING THIS PROCEDURE.

SUBJECT:

Flash: 845RE Transmission Shift Enhancements

OVERVIEW:

This bulletin involves reprogramming the Transmission Control Module (TCM) with the latest available software.

MODELS:

NOTE: This bulletin applies to vehicles within the following markets/countries: NAFTA, EMEA, APAC and LATAM.

NOTE: This bulletin applies to vehicles equipped with a 3.6L Engine (Sales Code ERB) and a 845RE 8 Speed Automatic Transmission (Sales Code DFL).

SYMPTOM/CONDITION:

A small number of customers may experience one or more of the following Symptom/Condition(s) and/or a Malfunction Indicator Lamp (MIL) due to an erroneous Diagnostic Trouble Code (DTC):

P1DCD – TCM monitoring processor performance multiple clutches locked up.
P1B13 – Park-By-Wire unintended out of park position.
P0734 – Gear 4 Shift Incorrect Ratio set in the TCM memory.

In addition, customers may experience the following conditions:

Bump sensation felt during engine start/stop transition on light throttle acceleration (Stop-Start Multiple VSM System Sales Code XBU equipped vehicles only).
Less than desired overall downshifts during normal driving.
Less than desired downshifts during passing maneuvers.
Less than desired upshift quality in lower gears.

The following improvements are included in this update:

**Engine start/stop calibration update to allow Park and Neutral to be considered valid stop positions (Stop-Start Multiple VSM System Sales Code XBU equipped vehicles only).**

DIAGNOSIS:

Using a Scan Tool (wiTECH) with the appropriate Diagnostic Procedures available in TechCONNECT, verify all related systems are functioning as designed. If DTCs or symptom conditions, other than the ones listed above are present, record the issues on the repair order and repair as necessary before proceeding further with this bulletin.

If the customer describes the symptom/condition listed above or if the technician finds the DTC, perform the Repair Procedure.

REPAIR PROCEDURE:

NOTE: Install a battery charger to ensure battery voltage does not drop below 13.2 volts. Do not allow the charging voltage to climb above 13.5 volts during the flash process.

NOTE: If this flash process is interrupted/aborted, the flash should be restarted.

Reprogram the TCM with the latest software. Detailed instructions for flashing control modules using the wiTECH Diagnostic Application are available by selecting the application’s “HELP” tab.
Clear any DTCs that may have been set in any module due to reprogramming. The wiTECH application will automatically present all DTCs after the flash and allow them to be cleared.

NOTE: Do not clear the shift adaptives in the TCM’s memory. This action may cause the transmission to not shift smoothly until the adaptives are re-learned.

POLICY:

Reimbursable within the provisions of the warranty.

TIME ALLOWANCE:

Labor Operation No:	Description	Skill Category	Amount
18-19-05-EB	Module, Transmission Control (TCM) – Reprogram (1 – Semi Skilled)	2 – Automatic Transmission	0.2 Hrs

NOTE: The expected completion time for the flash download portion of this procedure is approximately 1 minute. Actual flash download times may be affected by vehicle connection and network capabilities.

FAILURE CODE:

The dealer must choose which failure code to use. If the customer came in with an issue and the dealer found updated software to correct that issue, use failure code CC, for all other use failure code RF.

If the customer’s concern matches the SYMPTOM/CONDITION identified in the Service Bulletin, failure code CC is to be used.
If an available flash is completed while addressing a different customer concern, failure code RF is to be used.