1999 AUDI A4 sensor

28-2

Camshaft Position (CMP) sensor -G40-,
checking


Notes:

Camshaft Position (CMP) sensor -G40- is
located on the rear of the left cylinder head
(bank 2).
Checking -G163- page 28
-5

Component location page 24
-1

Required special tools and test equipment

VAG1598/22 test box
Multimeter US1119 (Fluke 83 or equivalent)
VW1594 connector test kit
Wiring diagrams
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28-3

Checking

- Disconnect 3-pin harness connector from
Camshaft Position (CMP) sensor -G40-.

If voltage is OK: - Connect multimeter US1119 (Fluke 83 or equivalent) to measure
voltage across CMP connector terminals 1 (B+) and 3 (Ground), using
adapters from VW1594 connector test kit.
- Switch ignition on.
- Measure voltage between terminals 1 and 3.
Specified value: 9-14.5 volts
- Switch ignition off.
- Connect VAG1598/22 test box to Motronic ECM harness connector
page 01
-67
.
- Check wiring for open circuit between ECM/test box and 3-pin harness
connector, according to wiring diagram.

Connector terminal 1 to ECM/test box socket 11
Connector terminal 2 to ECM/test box socket 44
Connector terminal 3 to ECM/test box socket 14
Specified value: max. 1.5
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28-4


If wiring is OK (and voltage across terminals 1 and 3 is OK):
If wiring is OK (but still no voltage across terminals 1 and 3): - Check wiring for short circuit between ECM/test box and 3-pin harness
connector, according to wiring diagram.

Connector terminal 3 to ECM/test box socket 44
Connector terminal 3 to ECM/test box socket 11
Connector terminal 2 to ECM/test box socket 11
Specified value:
- Replace Camshaft Position (CMP) sensor -G40-.
- Replace Motronic ECM -J220- page 01
-68
.
- Carry out adaptation of throttle valve control module to ECM page
24
-150
.
- Check readiness code page 01
-70
.
If Diagnostic Trouble Code (DTC) memory has been erased, or ECM
has been disconnected, generate new readiness code page 01
-73
.
Pa
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28-5

Camshaft Position (CMP) sensor 2 -
G163-, checking


Notes:

Camshaft Position (CMP) sensor 2 -G163- is
located on the front of the right cylinder head
(Bank 1).
Checking -G40- page 28
-2

Component location page 24
-1

Required special tools and test equipment

VAG1598/22 test box
Multimeter US1119 (Fluke 83 or equivalent)
VW1594 connector test kit
Wiring diagrams
Pa
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p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
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pair&id=AUDI.B5.FU03.28.1

28-6

Checking

- Disconnect 3-pin harness connector from
Camshaft Position (CMP) sensor 2 -G163-.

If voltage is OK: - Connect multimeter US1119 (Fluke 83 or equivalent) to measure
voltage across CMP connector terminals 1 (B+) and 3 (Ground), using
adapters from VW1594 connector test kit.
- Switch ignition on.
- Measure voltage between terminals 1 and 3.
Specified value: 9-14.5 volts
- Switch ignition off.
- Connect VAG1598/22 test box to Motronic ECM harness connector
page 01
-67
.
- Check wiring for open circuit between ECM/test box and 3-pin harness
connector, according to wiring diagram.

Connector terminal 1 to ECM/test box socket 11
Connector terminal 2 to ECM/test box socket 76
Connector terminal 3 to ECM/test box socket 67
Specified value: max. 1.5
Pa
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p://127.0.0.1:8080/audi/servlet/Dis
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28-7


If wiring is OK (and voltage across terminals 1 and 3 is OK):
If wiring is OK (but still no voltage across terminals 1 and 3): - Check wiring for short circuit between ECM/test box and 3-pin harness
connector, according to wiring diagram.

Connector terminal 3 to ECM/test box socket 76
Connector terminal 3 to ECM/test box socket 11
Connector terminal 2 to ECM/test box socket 11
Specified value:
- Replace Camshaft Position (CMP) sensor 2 -G163-.
- Replace Motronic ECM -J220- page 01
-68
.
- Carry out adaptation of throttle valve control module to ECM page
24
-150
.
- Check readiness code page 01
-70
.
If Diagnostic Trouble Code (DTC) memory has been erased, or ECM
has been disconnected, generate new readiness code page 01
-73
.
Pa
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p://127.0.0.1:8080/audi/servlet/Dis
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pair&id=AUDI.B5.FU03.28.1

28-8

Knock sensor and knock sensor control,
checking


Required special tools and test equipment

VAG1551/1552 Scan Tool (ST) with
VAG1551/3 adapter cable
VAG1598/22 test box
Multimeter US1119 (Fluke 83 or equivalent)
VW1594 connector test kit
Wiring diagrams

Checking

- Connect VAG1551/1552 Scan Tool (ST) 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.
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28-9

- Press buttons corresponding to following display
group numbers and press -Q- button to confirm
input.


022: Display group 22, for cylinders 1 and
2

023: Display group 23, for cylinders 3 and
4

024: Display group 24, for cylinders 5 and
6
Read Measuring Value Block 22 1 2 3 4

Indicated on display (1-4 display groups)
Note:
The test must be carried out during a road test because the knock sensor
system is only active with engine speed greater than 2600 RPM and
engine load greater than 3 ms.
WARNING!
A second technician is required to operate the VAG1551 scan tool
during the road test. Safety precautions page 24
-9 .
- Road test and compare display with specified values for knock sensor
system in display field 1-4.
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