High Pressure Sensor - G65 -

High Pressure Sensor -G65-, Checking

NOTE:
- The presence of -G65- is engine dependant. Where -G65- is not used, A/C pressure switch -F129- is used instead.
- Where -G65- is used, it's wiring circuit varies according to engine application (E.g.: some are connected to the ECM, some are not).
- Always confirm system use of either -065- or -F129- and applicable wiring circuit using applicable "Engine" and "Air conditioning" wiring diagrams.







Special tools and equipment required
- VAG 1767 Ignition tester
- VAG 1594/A (or C) Connector test set
- VAG 1598 A Test box
- Applicable wiring diagram
- In cases where refrigerant system may need to be recharged, use kent Moore ACR4 (or equivalent) (VAG 1885 illustrated).
- Where necessary: VAG 1551/1552 Scan Tool
- Optional: VAS 5051 Vehicle Diagnostic Testing and Information System







Test conditions
- Workshop temperature: 20-30 °C (68-86 °F)
- Engine at Workshop temperature.

Making connections


NOTE:
- The following test procedure is only possible on vehicles where the - G65- square wave signal to the coolant fan control module -J2293- is also transmitted to the Motronic Engine Control Module (ECM). Con firm -G65- circuit using wiring diagram.
- On vehicles where -G65- is NOT connected to the ECM, connect green clip from VAG 1767 directly to -G65- pin 2 using appropriate VAG 1594 adapter cable -7-. Proceed directly to checking
- Disconnect engine harness electrical connector from Engine Control Module (ECM) -3-.
- Locate correct test box VAG 1 598A -4- and adapter according to pin assignments of ECM -3- and connect test box to engine wiring connector/harness -2-.
- Connect black clip from VAG 1767 to Ground (GND) -5-.
- Determine applicable - G65- signal input pin assignment to ECM using wiring diagram. Example: T121/61


NOTE:
- As -G65- function primarily controls coolant fan and A/C clutch operation, the engine wiring diagrams may indicate the - G65- signal connection as being "Coolant fan control module connection".
- ECM terminal number assignments correspond with those on test box VAG 1598A.
- Connect green clip from VAG 1767 to the corresponding numbered position on test box VAG 1598A connected to -G65- pin -2- using appropriate VAG 1594 adapter cable - 7-. Example: 61


Checking
- Switch ignition on.
- Press button (arrow) for Duty Cycle measurement (modulation ratio) on ignition tester VAG 1767.

Test results, evaluating







NOTE: If a malfunction cannot be located, check DTC memory of Engine Control Module (ECM) and the Transmission Control Module (TCM) using VAG 1551/1552 Scan Tool. When doing so, note that DTCs related to high pressure sensor -G65- functions may be called-out as "A/C pressure switch -F129".