A/C "Cut-Off" During Light Acceleration (64 02 00)

Publication date: 2000-06-01
Reference number: 64 02 00

A/C "CUT-OFF" DURING LIGHT ACCELERATION

TECHNICAL SERVICE BULLETIN

Reference Number(s): 64 02 00, Date of Issue: June, 2000

BMW:	E38 740iL, 740i produced 9/98 - 1/00; E39 540i, 540iA produced 9/98 - 1/00
GROUP:	64 - Heating and Air Conditioning

NOTE: This bulletin is also issued in Group 12 (Engine Electrical), S.I. 12 05 00, the contents of which are identical.

SUBJECT

A/C "Cut-Off" During Light Acceleration - E38, E39 with M62TU

SITUATION

Customer complaint that the A/C is blowing warm air when accelerating lightly from a stop. The A/C functions properly during all other driving conditions.

CAUSE

DME/ECM calibration

CORRECTION

On a customer complaint basis only, reprogram the DME/ECM with CD 21.0 or higher.

PROCEDURE

After verifying the complaint:

Check the DME control unit numbers.

If the following numbers are listed, then no reprogramming is required, but further A/C diagnosis must be performed to repair the customer complaint:

CONTROL UNIT NUMBERS

Basic Control Unit	Vehicle	Programmed Control Unit
7506366	540i	7506506*
7506366	540iA	7506514*
7506366	540iA Sport	7506516*
7506366	540iAT	7506524*
7506366	740i/iL	7506554*
7506366	740iL Sport	7506556*
*Control unit numbers may change when new DIS software is released.

If the numbers listed above are not displayed program the DME and then verify that the control unit numbers have been correctly programmed. The numbers listed above will be displayed after reprogramming with CD21.0.
The new calibration will raise the A/C compressor "engine load cut-off" to 70%. The A/C compressor will still cycle off if the engine load is calculated to be 70% or greater. This A/C compressor "cut-of " will still occur, when the vehicle is accelerated hard (approximately 40 - 50 % throttle application) from a full stop, to allow for maximum engine power.

WARRANTY INFORMATION

Covered under the terms of the BMW New Vehicle Limited Warranty.

Check Control Unit #. No programming required.

WARRANTY INFORMATION

Model	Defect Code	Labor Operation	Labor Allowance
E38/E39	12 14 90 09 00	Main Work: 00 52 178	3 FRU
E38/E39	12 14 90 09 00	Associated Work: +00 52 775	2 FRU

Check Control Unit # and Reprogram DME

WARRANTY INFORMATION

Model	Defect Code	Labor Operation	Labor Allowance
E38	12 14 90 09 00	Main Work: 00 52 179	8 FRU
E38	12 14 90 09 00	Associated Work: +00 52 776	6 FRU
E39	12 14 90 09 00	Main Work: 00 52 179	9 FRU
E39	12 14 90 09 00	Associated Work: +00 52 776	7 FRU

The following explanations will spell out the correct use of the work times.

Main Work: Use this labor operation number when the only repair performed is the listed warranty repair.

Associated Work: Use this labor operation number when other repairs or services are performed along with the listed warranty repair.

Under no circumstances should both labor operation numbers be claimed. Attempts to claim both times will result in an unnecessary delay in claim processing and payment.