Vacuum Sensor - G608-, Checking

General Description

The Vacuum Sensor -G608- is installed in the line running to the brake servo unit. When the ignition is switched on, the pressure sensor is supplied with a voltage of 5 V. Inside the pressure sensor, there is a diaphragm with strain gauges. If the pressure within the sensor changes, the electrical resistance of the strain gauges also changes. This produces a voltage signal by means of an amplifier in the pressure sensor.

Special tools and workshop equipment required

Multimeter.
Wiring Diagram.
Scan Tool.

Test requirements

Fuses OK.
Battery voltage OK.
Switch OFF all electrical and electronic accessories.
Vehicles with automatic transmission, ensure the selector lever position is in "P".
Vehicles with manual transmission, ensure the shifter lever position is in "N" with the parking brake applied.
Observe all safety precautions: SAFETY PRECAUTIONS .
View clean working conditions: CLEAN WORKING CONDITIONS .

Test Procedure

Step	Procedure	Result / Action to Take
1	PERFORM: Preliminary Check to verify the customers complaint. Refer to PRELIMINARY CHECK . -- Was Complaint verified?	-- YES: GO TO: Step 2 Vacuum Sensor - G608-, CHECKING - 2 . -- NO: GATHER more information from customer about the complaint.
2	IGNITION: OFF. DISCONNECT: Vacuum Sensor -G608- harness connector. IGNITION: ON. CHECK: Vacuum Sensor -G608- harness connector terminals 1 to 2 for voltage. IGNITION: OFF. SPECIFIED VALUE: About 5.0 V. -- Was Value obtained?	-- YES: GO TO: Step 3 Vacuum Sensor - G608-, CHECKING - 3 . -- NO: GO TO: Step 4 Vacuum Sensor - G608-, CHECKING - 4 .
3	REMOVE: ABS Control Module -J104-. Refer to appropriate Service Information. CHECK: Vacuum Sensor -G608- harness connector terminal 3 to the ABS Control Module -J104- harness connector T46b / 38 for resistance. SPECIFIED VALUE: 0.5 Ω (± 0.3 Ω). -- Was Value obtained?	-- YES: REPLACE: Vacuum Sensor -G608-. Refer to appropriate Service Information. GO TO: Step 5 Vacuum Sensor - G608-, CHECKING - 5 . -- NO: PERFORM: Visual Inspection of wiring and component. CHECK: Wiring for open, high resistance, short or harness connector for damage, corrosion, loose or broken terminals. REPAIR: Faulty wiring or connector. GO TO: Step 5 Vacuum Sensor - G608-, CHECKING - 5 .
4	REMOVE: ABS Control Module -J104-. Refer to appropriate Service Information. CHECK: Vacuum Sensor -G608- harness connector terminal 1 to the ABS Control Module -J104- harness connector T46b / 44 for resistance. CHECK: Vacuum Sensor -G608- harness connector terminal 2 to the ABS Control Module -J104- harness connector T46b / 45 for resistance. SPECIFIED VALUE: 0.5 Ω (± 0.3 Ω). -- Were Values obtained?	-- YES: GO TO: Step 5 Vacuum Sensor - G608-, CHECKING - 5 . -- NO: PERFORM: Visual Inspection of wiring and component. CHECK: Wiring for open, high resistance, short or harness connector for damage, corrosion, loose or broken terminals. REPAIR: Faulty wiring or connector. GO TO: Step 5 Vacuum Sensor - G608-, CHECKING - 5 .
5	Final Procedure Perform a road test to verify repair. -- Does the original DTC return?	-- YES: CHECK: ABS Control Module -J104- harness connector for any damaged, pushed-out pins. REPAIR: As necessary. If all electrical connections are OK: REPLACE: ABS Control Module -J104-. Refer to appropriate Service Information. Clear the DTC's. Refer to DIAGNOSTIC MODE 04 -- ERASE DTC MEMORY -->. Repair is complete. Generate Readiness Code. Refer to READINESS CODE . Return vehicle to Customer. -- NO: Perform the diagnostic procedure for any DTC's. If no DTC's return, the repair is complete. Return vehicle to customer.