Checking intake manifold temperature sender — VW

AGR ALH AQM ASV AYQ
Special tools, workshop equipment, testers, measuring instruments and auxiliary items required

Hand multimeter V.A.G 1526 or multimeter V.A.G 1715
Fault reader V.A.G 1551 (or vehicle system tester V.A.G 1552) with cable V.A.G 1551/3
Adapter set V.A.G 1594
Test box V.A.G 1598/22
Current flow diagram

Test sequence

Connect fault reader V.A.G 1551 (V.A.G 1552) and select engine electronics control unit with the "Address word" 01. When doing this the engine must be running at idling speed.
(Connecting fault reader and selecting engine electronics control unit => Page
01-4
.)

Rapid data transfer
HELP
Select function XX
Indicated on display:

Press keys 0 and 8 for the function "Read measured value block" and confirm entry with Q key.

Read measured value block
Input display group number XXX
Indicated on display:

Press keys 0, 0 and 7 for "Display group number 7" and confirm entry with Q key.

Read measured value block 7
⇒
15.4 5C
15.9 5C
16.7 5C
Indicated on display:

Check value for intake manifold temperature in display zone 3. The value must be
about ambient temperature.
In case of a fault, a constant intake manifold temperature of 136.8°C will be displayed.
Press the ⇒key.
Press keys 0 and 6 for the "End output" function and confirm input with the Q key.
Switch off ignition.
If no realistic display appears in display zone 3 or a substitute temperature of 136.8 °C is displayed, check intake manifold temperature sender and the wiring to the sender as follows:

Engine codes AGP, AQM, AYQ

Engine codes AGR, ALH, ASV
=> Page
23-72
.

Pull 2-pin connector off intake manifold temperature sender (G72) -arrow-.

Measure resistance between sender contacts.

Specification see diagram

Scale A shows resistance values for temperature range 0...50 °C and scale B the values for temperature range 50...100 °C.

Examples:

30 °C corresponds to a resistance from 1500...2000 ω
80 °C corresponds to a resistance from 275...375 ω

If the specification is not obtained:

Replace intake manifold temperature sender (G72).

Interrogate fault memory, if necessary, repair any faults and then erase fault memory => Page
01-12
, interrogating and erasing fault memory.

If the specification is obtained:

Connect test box V.A.G 1598/22 to control unit wiring harness.

Check wiring between test box and 2-pin connector for open circuit using current flow diagram.
Contact 1+ socket 13
Contact 2+ socket 25
Wire resistance: max. 1.5 ω
Additionally check wires for short to one another, to vehicle earth and to battery positive.
Specification: ∞ω

If no fault is detected in the wiring:

Replace engine control unit
=> Page
23-134
.

Engine codes AGR, ALH, ASV

Pull 4-pin connector from intake manifold temperature sender (G72) with intake manifold pressure sender (G71) -arrow-.

Measure resistance between sender contacts 1 and 2.

Specification see diagram

Scale A shows resistance values for temperature range 0...50 °C and scale B the values for temperature range 50...100 °C.

Examples:

30 °C corresponds to a resistance from 1500...2000 ω
80 °C corresponds to a resistance from 275...375 ω

If the specification is not obtained:

Replace intake manifold temperature sender (G72) with intake manifold pressure sender (G71).
Interrogate fault memory, if necessary, repair any faults and then erase fault memory => Page
01-12
, interrogating and erasing fault memory.

If the specification is obtained:

Connect test box V.A.G 1598/22 to control unit wiring harness.

Check wiring between test box and 4-pin connector for open circuit according to current flow diagram.
Contact 1+ socket 25
Contact 2+ socket 13
Wire resistance: max. 1.5 ω
Additionally check wires for short to one another, to vehicle earth and to battery positive.
Specification: ∞ω

If no fault is detected in the wiring:

Replace engine control unit
=> Page
23-134
.