1999 AUDI A4 check engine

24-66

Engine operating conditions (engine
electronics), checking


Note:
This test checks whether the Motronic Engine
Control Module (ECM) -J220- recognizes the
engine operating conditions.

Required special tools and test equipment

VAG1551 or VAG1552 scan tool with
VAG1551/3 adapter

Test requirements
Engine oil temperature at least 80 C (176
F)

Checking

- Connect VAG1551 or VAG1552 scan tool and
press buttons -0- and -1- to insert "Engine
Electronics" address word 01 (with engine
running at idle) page 01
-8 .
Rapid data transfer
HELP
Select function XX

Indicated on display
- Press buttons -0- and -8- to select "Read Measuring Value Block"
function 08, and press -Q- button to confirm input.
Pa
ge 85 of 166 Motronic Multi
port Fuel In
jection
(MFI
) and i
gnition s
ystem
11/23/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU03.24.1

24-67

- Check engine operating conditions (display field
4):

Display fields

1 2 3 4
Display group 5: Engine electronics-operating conditions
Display xxx RPM xx.xx ms xxx km/h Idle
Part throt
Full throt 1)
Decel
Enrich
Indicates Engine speed
(in 40 RPM steps) Engine load Vehicle speed Operational condition
Range 0 - 6800 RPM 0.00 - 12.75 ms --- ---
Specified value 620 - 740 RPM
(all-wheel drive)
or
740 - 860 RPM
(front-wheel drive) 1.00 - 2.50 ms 0 km/h Idle: "Idle"
Pa
ge 87 of 166 Motronic Multi
port Fuel In
jection
(MFI
) and i
gnition s
ystem
11/23/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU03.24.1

24-71
Evaluation of display group 2, display field 2 Display group:
2


Display field:
2
Possible malfunction cause
Corrective action
less than 1.00
ms
Smaller values can only occur while driving during
deceleration
more than 2.50
ms Shift lever in drive range (auto. transmission)
Engine is affected by additional consumers- Move shift lever into P or N
- Eliminate load (A/C, power steering, generator)

Poor idle (does not run on all cylinders)- Check and spark plugs page 28
-21
(checking
ignition coils)
- Check fuel injectors page 24
-102


Throttle valve control module -J338- faulty- Check throttle valve control module page 24
-
128

Pa
ge 93 of 166 Motronic Multi
port Fuel In
jection
(MFI
) and i
gnition s
ystem
11/23/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU03.24.1

24-72
Evaluation of display group 2, display field 4 Display
group: 2


Display field:
4
Possible malfunction cause
Corrective action
less than 2.8
g/s
Large amount of false air between intake air duct and
Mass Air Flow (MAF) sensor - Check intake air system for leaks (false
air) page 24
-126

larger than 5.6
g/s
Shift lever in drive range (auto. transmission)
Engine affected by additional consumers- Move shift lever into P or N
- Eliminate load (A/C, power steering,
generator)

Open circuits in wire 1 or 2 between MAF sensor and
ECM - Check voltage supply page 24
-73


Open circuit in wire 3 between MAF sensor and relay
panel - Check wiring page 24
-73
Pa
ge 94 of 166 Motronic Multi
port Fuel In
jection
(MFI
) and i
gnition s
ystem
11/23/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU03.24.1

24-75

Engine Coolant Temperature (ECT)
sensor, checking


Required special tools and test equipment

VAG1551 or VAG1552 Scan Tool (ST) with
VAG1551/3 adapter cable
VAG1598/22 test box
Multimeter US1119 (Fluke 83 or equivalent)
VW1594 connector test kit
Wiring diagram

Test requirements
Engine cold
Pa
ge 98 of 166 Motronic Multi
port Fuel In
jection
(MFI
) and i
gnition s
ystem
11/23/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU03.24.1

24-76

Checking

- Connect VAG1551 or VAG1552 scan tool and
press buttons -0- and -1- to insert "Engine
Electronics" address word 01 (with ignition
switched on) page 01
-8 .
Rapid data transfer
HELP
Select function XX

Indicated on display
- Press buttons -0- and -8- to select "Read Measuring Value Block"
function 08, and press -Q- button to confirm input.
Read Measurin
g Value Block
HELP
Input displa
y group number XXX

Indicated on display
- Press buttons -0-, -0- and -4- to input display group number 4 (004),
and press -Q- button to confirm input.
Read Measuring Value Block 4 1 2 3 4

Indicated on display (1-4 = display fields)
Pa
ge 99 of 166 Motronic Multi
port Fuel In
jection
(MFI
) and i
gnition s
ystem
11/23/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU03.24.1

24-77

- Compare display with specified value for engine
coolant temperature sensor (display field 3):

Display fields

1 2 3 4
Display group 4: General engine data
Display xxx RPM xx.xxx V
xxx.x C
xxx.x C
Indicates Engine
speed
(in 40 RPM
steps) Battery Positive
Voltage (B+) Engine coolant temperature Intake air
temperature
Range 0 - 6800
RPM 0.000 - 16.500 V -46.5 to 141.0 -46.5 to 141.0
Specified
value 0 RPM 10.000 - 14.500 V approx. ambient temperature 1), 2) ---

--- --- If specified value is not attained page 24
-79
,
Evaluation of display group 4
---
1) After a long standing period (approx. 12 hours). 2) If indicated temperature deviates significantly from the ambient temperature, check ECT sensor wiring for resistance or
open circuits.
Pa
ge 100 of 166 Motronic Multi
port Fuel In
jection
(MFI
) and i
gnition s
ystem
11/23/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU03.24.1

24-81
If wiring is OK:

- Check ECT sensor resistance across terminal 1 (signal) and terminal 3
(ground).
- Check measured resistance value for appropriate temperature range
using graph below (N24-0157).

Range A: 0-50 C (32-122 F)

Range B: 50-100 C (122-212 F)

Examples:
If resistance is NOT OK:
At 30 C, ECT sensor resistance should be 1500-2000 At 80 C, ECT sensor resistance should be 275-375
- Replace Engine Coolant Temperature (ECT) sensor -G62-.
- Check readiness code page 01
-70
. If Diagnostic Trouble Code
(DTC) memory has been erased, or ECM was disconnected, generate
new readiness code page 01
-73
.
Pa
ge 105 of 166 Motronic Multi
port Fuel In
jection
(MFI
) and i
gnition s
ystem
11/23/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU03.24.1