CMP Sensor 1, G40 & Sensor 2, G163 Checking

Camshaft Position (CMP) Sensor - G40 and Camshaft Position (CMP) Sensor 2 -G163, Checking

The Camshaft Position (CMP) sensor -G40 indicates the ignition position for Cylinder 1.

If the Hall sensor fails to function, the knock control is switched off and the ignition timing is retarded slightly because cylinder assignment is no longer possible.

Even without a signal from the Hall sensor the engine will continue to run and can also be restarted

- If a malfunction is detected the engine control module produces one spark per crankshaft revolution for each cylinder.
- When the injection system is one revolution out of phase it does not have any noticeable effect on the fuel injection. If this happens, the fuel is injected upstream of the closed inlet valve instead of while the inlet valve is open. This has only a minor influence on the quality of the air/fuel mixture.


NOTE:
- The camshaft position (cmp) sensor -G40 is located at the rear of the left-hand cylinder head (bank 2).
- The camshaft position (cmp) sensor 2- G163 is located at the front of the right-hand cylinder head (bank 1).



Checking activation of Hall sensor (camshaft position sensor)

Use test leads VAG1594 connector test kit when carrying out the following tests.
- Push back rubber grommet on relevant Hall sensor connector.







- Connect VAG1527 diode test lamp to terminals 1 and 2 of hall sensor connector from behind (without disconnecting connector from hall sensor).


NOTE: The connector terminals are numbered on the back of the connector.


- Operate starter for few seconds.

The diode test lamp should blink briefly once every two engine revolutions.


NOTE: Diode test lamps with a low current draw continue to glow faintly between impulses from the engine control module (rather than going out completely) and become much brighter when receiving an impulse.


If the diode test lamp does not flash, test the voltage supply.

Checking voltage supply for Hall sensor
- Disconnect harness connector from relevant Hall sensor.
- Switch ignition on.







- Connect multimeter (Fluke 83 or equivalent) (voltage measurement range) between engine Ground (GND) and socket 1 of connector.

Specification: approx. 5 V

Checking signal wire for Hall sensor
- Switch ignition on.







- Connect multimeter (Fluke 83 or equivalent) (voltage measurement range) between engine Ground (GND) and socket 2 of relevant connector.

Specification: approx. battery voltage

Checking Ground (GND) wire for Hall sensor:
- Connect multimeter (Fluke 83 or equivalent) (resistance measurement range) between socket 3 on connector and engine Ground (GND).

Specification: Continuity

Resistance in wiring: max. 1.5 Ohms

If all the readouts match the specifications but the diode test lamp does not flash







(measurement taken between terminals 1 and 2 without unplugging connector and while operating starter):

- Replace relevant Hall sensor.

If the readouts do not match the specification, check the wiring.

Checking wiring between Hall sensor and engine control module
- Connect VAG1598/31 test box to wiring harness for engine control module. Do not connect to the engine control module itself. Refer to "Scan Tool Testing/Scan Tool Connecting and Initial Checks/Connecting VAG1598/31 Test Box" Testing and Inspection







- Check wiring connection from Hall sensor to engine control module for open circuit and/or short circuit to B+ or Ground (GND).







Resistance in wiring: max. 1.5 ohm

- Repair any open/short circuit as necessary.
- If all the test results so far have been OK but a malfunction related to the camshaft sensor (Hall sensor) is displayed again after erasing the DTC memory as a test measure, the cause may be as follows:
- Rotor ring for Hall sensor misaligned; test phase position.

Checking phase position of Hall sensor
- Connect vehicle diagnostic, testing and information system VAS5051 or VAG1551 scan tool and select engine electronics control module by entering address word "01". When doing this the engine must be idling. Refer to "Scan Tool Testing/Scan Tool Connecting and Initial Checks/Connecting VAS5051 or VAG1551" Testing and Inspection

Indicated on display


Rapid data transfer HELP
Select function XX


- Press buttons -0- and -8- to select function "Read Measuring Value Block" and confirm entry with -Q- button.


Indicated on display:


Read Measuring Value Block
Input display group number XXX


- Press buttons -0-, -9- and -3- to select "Display Group 093" and confirm entry with - Q- button.


Indicated on display


Read Measuring Value Block 93 ->
1 2 3 4







- Check specified display values for Hall sensors.