Engine Knock; Knock Sensor Test Procedure - Actron CP9087 Service Manual

Knock Sensor Test Procedure

Sensor may be tested on or off vehicle.
Warning: Observe all safety precautions (see page ii) if testing sensor on vehicle.
HIGH
LOW
POWER OFF
RANGE
VOLTS
OHMS
FREQUENCY
FUNCTION
TEST
1) Verify ignition key is OFF.
2) Check Tester battery (refer to page 1-4).
3) Disconnect wiring harness from sensor - Inspect for
damage.
4) Connect test leads to sensor.
One-wire connector:
• YELLOW test lead to signal pin (top of sensor).
• BLACK test lead to body of sensor (off-car) or nearby
ground (on-car).
Two-wire connector:
• YELLOW test lead to either sensor pin.
• BLACK test lead to remaining sensor pin.
5) Set RANGE switch to LOW.
6) Set FUNCTION switch to VOLTS.
7) Operate sensor - Watch TEST light for results.
(Note: Ignore any RICH/LEAN light flashes.)
On-car test: Lightly tap surface near sensor using a
socket extension (or similar tool) and a light hammer.
Do not tap directly on sensor!
Off-car test: Grasp sensor firmly. Gently tap sensor tip
with a light hammer.
– Good sensor: TEST lights flash upward from the
bottom of the TEST light column during a tap. (Only a
few lights may flash. This is O.K.) Range of TEST light
movement varies with sensor type and tapping force.
– Bad sensor: TEST lights do not flash during a tap.
8) Testing is complete.

Engine KNOCK

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