SW2 L4-1.9L DOHC VIN 7 (1997)
the terminal won't be damaged.
The second function is to determine if a terminal's contacts have been spread apart, making an open or intermittent open. This is known as a terminal
tightness test. Connector terminals make contact with the pin by means of a tang which is sprung against the pin. If the tang is spread apart by a meter
probe, the tang will not spring back to tightly grip the pin. Test this by inserting the jumper pin and removing it, noting how well the terminal holds the
pin. It should be held well enough that the pin will not fall out of the terminal.
Diagnostic Service Probe
Diagnostic Service Probe
IMPORTANT: Diagnostic service probes are for use on 0.35, 50 and 0.80 mm (22, 20 and 18 gage) wires only.
IMPORTANT: The diagnostic service probes must be left on the wire after use. The probe contains a sealant that will protect the wire from corrosion.
Do not remove the diagnostic service probe after use.
The use of the diagnostic service probe offers many advantages in system diagnostics over the old jumper wire and terminal back-probe methods. The
most important advantage of the diagnostic service probe method of diagnostics is the ability to observe the operation of a circuit without disturbing the
components or connections. This is an important advantage since many circuit failures are vibration or connection related. The diagnostic service probe
is designed to firmly hold multimeter test probes to allow more accurate readings while the circuit is operating. Circuits with bad connectors, grounds or
components are easier to diagnose while they are operating.
Attach the diagnostic service probe to the wire leading to the connector and insert your multimeter into the diagnostic service probe. Put the meter on the
appropriate scale and observe the readings. If the readings do not compare with the expected readings, gently wiggle the wire back and forth in the
connector. If the reading on the meter changes while you are wiggling the wire, the terminal or connector are faulty. Disconnect the connector and
examine the terminals and connector cavities for damage. Check the terminals to see if a known good terminal makes a firm connection. Do this by
inserting a known good male terminal into the female terminal you are testing. The male terminal should be held firmly in place by the female terminal
and should not be loose enough to fall out if the female terminal is held downward. Likewise, test a male terminal by inserting it into a known good
female terminal. The two terminals should fit snugly together and should not separate if the male terminal is held vertically downward.
If the connections are good (both wire connections and the connection to the component), check the ground connection. Attach a diagnostic service
probe to the ground side of the circuit or component. Place a multimeter probe in the diagnostic service probe and the other probe to a known good
ground.
NOTICE: Check the accuracy of the multimeter first by touching the leads together. The meter should read less than 0.10 ohm with the leads touching.
Place the multimeter on the lowest ohmmeter scale. The meter should read less than one ohm, If the meter reads more than one ohm, check the
connections to the ground splice pack (if applicable) or check the ground attachment point. Attach a jumper wire from the ground attachment ring
terminal. Attach it to the ring terminal without moving or disturbing the terminal fastener. This can be done by attaching the jumper wire to the crimp
lead part of the ring terminal. Attach the other end of the jumper wire to a known good ground and watch the multimeter to see if the reading goes below
one ohm. If the reading goes below one ohm, remove the ground screw or nut, clean the connection surfaces and install, If the reading stays above one
ohm, check for an open in the ground wire. Also check for continuity from the component to the diagnostic service probe.
Other uses for the diagnostic service probe:
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Compare voltage readings across connectors, components, or lengths of wire. This allows you to observe the operation of a circuit without the
addition of jumper wires or back-probing connections. The best time to diagnose most circuits is while they are operating.
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Observe changing voltages and compare them to what the PCM is reporting. This can be done by comparing the voltage readings of the PCM
inputs to the reported PCM readings displayed on the portable diagnostic tool (PDT) or the Service Stall System (SSS). This can help detect
damaged or faulty PCM connections, or a faulty PCM.
IMPORTANT: There are differences between the actual voltages from the sensors and the reported voltages by the PCM. This is due to the
