Engine Speed Sensor -G28-, Checking

Function

The Engine Speed Sensor -G28- detects RPM and reference marks from a tooth wheel on the Crankshaft, without an engine speed signal, the engine will not start. If the engine speed signal fails while the engine is running, the engine will stop immediately.

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 Auto. Transmission, ensure Selector Lever position is in "P".
Vehicles with Man. Transmission, ensure Shifter Lever position is in "N" with Parking Brake applied.
Coolant Temperature: ≥ 80 °C.
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 ENGINE SPEED SENSOR -G28-, CHECKING => 2 NO: Gather more Information from customer about the complaint
2	CONNECT: Scan Tool. START or CRANK: Engine CHECK: Engine RPM: SPECIFIED VALUE: Cranking or Idle RPM -- Was value obtained?	YES: Go to Step 3 ENGINE SPEED SENSOR -G28-, CHECKING => 3 NO: Go to Step 4 ENGINE SPEED SENSOR -G28-, CHECKING => 4
3	CONDITION: May be intermittent PERFORM: Visual Inspection of wiring and component CHECK: wiring for open, high resistance, short or electrical connector for damage, corrosion, loose or broken terminals REPAIR: faulty wiring or connector	GO TO: Step 7 in ENGINE SPEED SENSOR -G28-, CHECKING
4	DISCONNECT: Engine Speed Sensor -G28- electrical connector IGNITION: ON CHECK: Engine Speed Sensor -G28- wiring connector pins 1 to 3 for voltage SPECIFIED VALUE: About 5.0 V IGNITION: OFF -- Was value obtained?	YES: Go to Step 5 ENGINE SPEED SENSOR -G28-, CHECKING => 5 NO: Go to Step 6 ENGINE SPEED SENSOR -G28-, CHECKING => 6
5	REMOVE: Engine Control Module - J623-. Refer to appropriate service information. CHECK: Engine Speed Sensor -G28- electrical connector terminal 2 to the Engine Control Module - J623- electrical connector T105 / 18. SPECIFIED VALUE: 0.5 Ω (± 0.3 Ω) -- Was value obtained?	YES: REMOVE: Engine Speed Sensor -G28-. Refer to appropriate repair information. CHECK: sensor wheel for proper seating, damage and/or run - out. Refer to appropriate repair information. Sensor wheel OK REPLACE: Engine Speed Sensor -G28-. Refer to appropriate repair information. GO TO: Step 7 in ENGINE SPEED SENSOR -G28-, CHECKING NO: CHECK: wiring for open, high resistance, short or electrical connector for damage, corrosion, loose or broken terminals REPAIR: faulty wiring or connector GO TO: Step 7 in ENGINE SPEED SENSOR -G28-, CHECKING
6	REMOVE: Engine Control Module - J623-. Refer to appropriate service information. CHECK: Engine Speed Sensor -G28- electrical connector terminal 1 to the Engine Control Module - J623- electrical connector T105 / 21. CHECK: Engine Speed Sensor -G28- electrical connector terminal 3 to the Engine Control Module - J623- electrical connector T105 / 19. SPECIFIED VALUE: 0.5 Ω (± 0.3 Ω) -- Was value obtained?	YES: REPLACE Engine Control Module -J623- Refer to appropriate repair information GO TO: Step 7 in ENGINE SPEED SENSOR -G28-, CHECKING NO: CHECK: wiring for open, high resistance, short or electrical connector for damage, corrosion, loose or broken terminals REPAIR: faulty wiring or connector GO TO: Step 7 in ENGINE SPEED SENSOR -G28-, CHECKING
7	Final Procedure Perform a road test to verify repair. Do any DTC's return:	YES: Check the DTC memory. Refer to DIAGNOSTIC MODE 03 - READ DTC MEMORY . Perform the diagnostic procedure for that DTC. NO: Repair is complete, Generate readiness code. Refer to READINESS CODE . Return vehicle to Customer