GxT Ferret 74 User Manual

Always wear eye protection when testing vehicles. Be extra careful near

water. Follow up with a neutralizing solution of baking soda and then more

water.

one has been disconnected. Contact between the vehicle body metal and

the hot terminal can cause sparks to ignite gas or even weld tools into a

automatic parking brake releases.

Avoid electrical shocks caused by getting close to live ignition wires or

touching the coil TACH terminal. A personʼs reaction near a live engine can

the hazard of igniting gasoline vapor.

GxT, Inc. of Cheboygan Michigan, warrants to the original purchaser that FERRET brand

products are free from defects in materials and workmanship for a period of two years from

date of purchase. Our sole obligation for a product within the above warranties will be to

within the U.S.A., shipping prepaid, if it is sent to our Repair Department shipping prepaid

and accompanied by proof of purchase.

This Warranty does not apply to products which have been altered outside the factory; or

been damaged from accidents, negligence, or abuse; or have been used differently than de-

scribed in the printed instructions. Please note that wear and tear on leads and replacement

of consumable items such as: NOx Sensors, Oxygen Sensors, and paper, is not covered

by warranty.

GxT Inc.ʼs sole liability and buyerʼs exclusive remedy is limited to repair or replacement of the

product as stated in the Limited Product Warranty. THERE ARE NO OTHER WARRANTIES

A PARTICULAR PURPOSE AND GxT, INC. SHALL NOT BE LIABLE FOR INCIDENTAL OR

CONSEQUENTIAL DAMAGES ARISING FROM THE SALE OR USE OF THE PRODUCT.

Some states do not allow limitations on the length of implied warranties nor exclusion or limita-

tions of incidental or consequential damages, so that the above limitations and/or exclusion

This warranty gives you specifi c legal rights and you may also have other rights which may

vary from state to state.

Ground

Test

OPERATORʼS MANUAL

© Copyright 2005, GxT, Inc., All Rights Reserved

The Ferret 74 can be used to quickly and accurately diagnose the operation of

Titania and Zirconia Oxygen Sensors. At any time a rich or lean signal can be

sent to the ECM to monitor the response of the O2 Sensor.

Testing Procedures

to choose between Zirconia, Titania, or Crossings tests.

2. Connect the ground lead to a good engine ground.

3. Connect the test lead to the signal wire that runs from the O2 sensor to

the ECM. The indicators on the 74 will help you connect to the proper

wire. All indicators should be off. Make sure the key is on, or the engine is

5. Read the Rich/Lean status or Crossings per Second on the bargrarph.

extreme electromagnetic fi elds it may step to the next operating mode. Simply

affected.

A single element of the bargraph will illuminate to indicate the voltage of the O2

sensor. An active sensor will display a rapidly moving segment.

Crossings per Second is a direct measurement of the activity level of the O2

Sensor. Crossings are calculated by the number of times per second that the

O2 voltage level crosses .45 volts.

There are four indicators to help you connect to the proper wire. The indicators

are: GND, ECM, HTR, and OPEN.

GND The test lead is connected to ground.

Open The test lead is not connected.

Zirconia The Zirconia test method has been selected

When the Rich Button is pressed, all of the bargraph segments under the Rich

the Lean Button is pressed, all of the bargraph segments under the Lean portion

of the graph will illuminate while a lean signal is sent to the ECM.

When you press the Rich button a Rich signal will be sent to the ECM for 5

seconds. When you press the Lean button a Lean signal will be sent to the

CAUTION: Do not continuously send a Rich or Lean signal to the ECM without

allowing time for the engine to stabilize between signals.

Analysis of Test Results

One of the most important indicators of engine performance is a properly

functioning Oxygen Sensor. A properly functioning fuel control system will have

an oxygen sensor that is rapidly oscillating between a Rich and Lean state.

We measure this as Crossings per Second. Typical crossings per second for

warm engines running at a steady fast idle are in the 1 to 3 range. Low rates

carbureted engines the slowest.

When used with a variety of additional test equipment, the 74 will greatly speed

the diagnosis of drivability problems. Here are some examples.

Scan Tool

The Rich or Lean state measured by the 74 should agree with what is displayed

from the Scan Tool.

of the injector. This confi rms the ECMʼs control of fuel delivery.

Gas Analyzer

Confi rm the Oxygen Sensor is properly measuring the exhaust by comparing

the Rich Lean status with the Gas Analyzer Readings.

Technical Support

Questions or inquiries about service can be answered by contacting GxT, Inc.,

at: Toll Free [phone]. Fax: [phone], Toll Free [phone], or

GxT, Inc., 520 MM Riggs Drive., Cheboygan, MI 49721-1061