Generations

Engine Codes

Engine code	MY	Model	ECU	Notes
APB	1998-2001	North American S4	see below
ASJ	2000?	RS4	F-box
AZR	2001?-2003		Q/K-box
AGB	1997-2001?	European S4	C/D-box	No post cat O2 sensors, Bosch MAF, original intake manifold
AZB	2001?		G/N/P-box
APB	2000-2002	allroad/A6	4Z7..X/L, 4B0..X/K-box	4B0 - A6, 4Z7 - allroad, ME7.1
BEL	2003-2004		4Z7..MX/T, 4B0..AA/R/P/S	4B0 - A6, 4Z7 - allroad, ME7.1.1

• http://www.audizine.com/forum/showthread.php/365283-Which-model-ECM-for-2004-allroad?p=5306106&viewfull=1#post5306106

OEM equipment

MY	Badge	ECU	Build Date	MAF	BPVs	ESP	Transmission	F-hose	Notes
1997-1999		C-Box	09/97-08/99	Bosch	710	no	6-speed	yes	AGB engine code (Not available in North America), Flush door handles, Early door mirrors, Thin door trim, Analog clock in dash, No plenum chamber cover, Reversed battery terminals, Face down spare, Square side repeaters, Washer nozzles located on top of hood, Manually operated seats, Split (2-piece) Xenons with separate side repeaters
2000		A-Box	09/99-05/00						Possibly Al uprights, interchangable with ESP/Hitachi equipped cars but requires engine recode and a Bosch MAF
		B-Box			710A		Tiptronic	no	Possibly Al uprights, interchangable with ESP/Hitachi equipped cars but requires engine recode and a Bosch MAF
2001		H-Box	06/00-09/00	Hitachi	710A	yes	6-speed	yes	Steel uprights, introduction of ESP, interchangable with M-Box but requires cluster recode
		J-Box					Tiptronic	no	Steel uprights, interchangable with L-Box
2001.5		L-Box	09/00-05/01		710B				Revised TBB, updated intake manifold, sport package (w/Al mirrors) avail, Avant avail
		M-Box					6-speed
2002		T-Box	06/01-07/01						Interchangable with M-Box
		AA-Box					Tiptronic		Interchangable with L-Box

Notes

• The build date cutoff for 2001 to 2001.5 is inconsistent and sometimes arbitrary. Both '01 and '01.5 cars have been reported as 09/00 build.
• Manufacturer Year is inconsistent and sometimes arbitrary. See Notes below.
• It is a common misconception that 2001.5 introduced updated oil lines. There is no conclusive evidence of this.
• http://forums.audiworld.com/s4/msgs/802094.phtml
• poll here: http://forums.audiworld.com/s4/msgs/2447926.phtml
• There is some confusion with cars near the 5/00 build mark (none verified)
  1. Some 2001 cars came with Bosch MAFs (and presumably A-Box ECUs).
• There is some confusion with cars near the 09/00 build mark (none verified)
  1. Some are 2001, some are 2001.5
  2. Some 2001.5 came with H-boxes and do not appear to have F-hoses
  3. Some 2001.5 are reported to have mismatching wheel/trunk badges
• Andy Whittaker's UK 1999 S4 seems to have a C box as too does Nilesh "Ram" Ramrattan's MTM Stage IV car (also UK spec).
• The L and AA box information may be incorrect. Please mail me or post a comment in the talk section.
• If the OEM equipment on your car does not fit into this table and you are the original owner, please post a comment in the talk section.
• If the OEM equipment on your car does not fit into this table and you are not the original owner, it is highly likely that some of the parts have been swapped out.

Compatibility with A6 2.7ts

• C5 A6 ecu's work on a S4 using a bench flasher in boot-mode to bypass the IMMO-EEPROM.
• The ECU must maintain the same transmission for which it was designed.

Box	MY	Rev	Notes
4B0 907 551 K	'00	APB ME7.1	6sp
4B0 907 551 P	'01
4B0 907 551 AA
4B0 907 551 AK	'02
4B0 907 551 L	'00		tip
4B0 907 551 Q	'01
4B0 907 551 T
4B0 907 551 AL	'02
4B0 907 551 R	'03	BEL ME7.1.1	Not s4 compatible
4B0 907 551 AA
4B0 907 551 P	'04
4B0 907 551 S

Compatibility with allroad 2.7ts

Box	MY	Rev	Notes
4Z7 907 551	??	APB ME7.1	6mt?
4Z7 907 551 X	'01		?
4Z7 907 551 K	'01		6mt?
4Z7 907 551 L	'01		tip and 6mt?
4Z7 907 551 MX	'??	BEL ME7.1.1	not s4 compatible
4Z7 907 551 S	'03
4Z7 907 551 T	??
4Z7 907 551 AA	'04

North American Production numbers

MY	Sedan	Avant	total
2000	5647	25	5672
2001	4770	1228	5998
2002	642	198	840
Total	12,096	1451	13,547

2002 is build date of 06/01 to 07/01

B5 S4 Avant: Audi Import Figures (U.S. Market Only.)

Model Year	Total Imported	Automatic	6-Spd Manuals
2001	1,257	404	853
2002	283	188	95
Total	1540	592	948

Notes

• Audi did sell some B5/S4 Avants in 2000CY, but they were early '01MY models.
• Audi is not able to differentiate between 2001MY and 2001.5 MY S4 Avants in their U.S. Market Import / Sales records.
• Audi did not produce a 2003MY B5/S4 Avant. However, there were a few "left-over" 2002MY units sold in 2003CY.

Source: Audi's "Product Support Engineering" office in Auburn Hills, Michigan.

AoA has confirmed the following "U.S. Import" figures for "Silver" (Exterior Paint Code 5B5B) B5/S4 Avants:

- B5/S5 Avants in Silver (Total 2001 & 2002 Models): 672 Vehicles.

- B5/S4 Avants in Silver with 6-Spd Manual (Total 2001 & 2002 Models): 399 Vehicles.

- B5/S4 Avants in Silver with 6-Spd Manual (2001 Model Year only): 358 Vehicles.

Of these 358 Silver 2001 B5/S4 Avant 6-Speed Manuals....

...24 were '01 B5/S4 Avant Silver 6-Spd Manuals with "Silver Interiors".

...51 were '01 B5/S4 Avant Silver 6-Spd Manuals with "2-Tone / Black & Silver Interiors".

...283 were '01 B5/S4 Avant Silver 6-Spd manuals with "Black Interiors".

Source: Audi's "Product Support Engineering" office in Auburn Hills, Michigan. (Silverarrow)