TM Automotive LabScope On/Off Button 91 AC Adapter Input (Optional) RS232 Port Channel 1,2, and Common Inputs Help Button Select Buttons Hold Button Reference Button KV Probes Labscope KV Adapter Channel 1 Volts/Div Button Channel 2 Volts/Div Button Trigger Level Button Time/Div Button Trigger Pickup OPERATOR’S MANUAL Test Probes 1
Contents Specifications .......................................................................................................... 3 Front Panel Controls ............................................................................................... 4 Understanding the Display ..................................................................................... 5 External Connections ............................................................................................. 5 Manual Setup ................
Contents Secondary Ignition ................................................................................. Communication Tests - Serial Data....................................................................... Electrical Tests ...................................................................................................... Apply Switch .......................................................................................... Alt Field Ctrl ..........................................................
Front Panel Controls ON/OFF To maximize battery life, the Ferret 91 includes an auto shut off feature. If no buttons are pushed for approximately five minutes (20 minutes at a setting of 60 sec/division), the Ferret 91 will turn off the LCD display and all associated circuitry. To return to live operation, push any button. SELECT Press the SELECT button to access the main menu, and to begin the selection process for setup and measurement.
Understanding the Display Measurement Display Area Channel 1 Voltage Scale _______ _______ Indicates Trigger Position Channel 2 Voltage Scale Waiting for Trigger Signal W Indicates AC Coupling for Channel 1 Indicates AC Coupling for Channel 2 Indicates Channel 2 Filter is On Indicates Channel 1 Filter in On Trigger Slope Trigger Level Horizontal Time/Division External Connections COM Signal ground connection. Common for CH1 and CH2. CH1 Input for CH1 signal.
Manual Setup Use the up/down arrow buttons to move the arrow to the desired menu selection. The current selection for each command is indicated by the reversed video. Press SELECT to highlight the other function. Select OK to begin operation. CH1POS: BOTT CENT The highlighted command positions the ground reference on the bottom or center of the screen. Pressing both the up and down segments of the CH1 key will perform the same operation.
Manual Setup COUPLING2: AC DC Provides same functions for Channel 2 as described for Channel 1 COUPLING. When in AC-coupled mode, a small sinewave appears in the lower right corner of the display. FILTER2: OFF ON Provides same function for Channel 2 as described for Channel 1 FILTER. When FILTER2 is ON, and “F” appears in the lower right corner of the display. CONTRAST: Allows the display contrast to be adjusted through a range of 0 (least contrast) through 10 (highest contrast).
Sensor Tests ABS Wheel Speed Connect COM probe to the sensor “low”, “-”, or ground circuit. Connect CH1 probe to the sensor “high”, “+” or signal output to the ABS control unit. Spin the wheel and look for symmetrical oscillations that increase in amplitude as wheel speed increases. Oxygen Sensor 1V Connect COM probe to the O2 sensor ground circuit or sensor body (NOT the negative battery terminal). Connect the CH1 probe to the O2 sensor signal wire to the PCM. Warm the engine for 2-3 minutes at 2500 RPM.
Sensor Tests Intake Air Temp IAT Connect COM probe to the sensor’s ground circuit, engine block, or negative battery post. Connect the CH1 probe to the sensor’s signal to the PCM. Spray the sensor tip with cooling spray or begin the test at the suspected temperature range and verify the signal’s amplitude is within its limits for the given temperature. Opens will appear as upward spikes to VRef. Shorts will appear as downward spikes to ground.
Sensor Tests Throttle Position Connect COM probe to the sensor’s ground circuit, engine block or negative battery post. Connect the CH1 probe to the sensor’s signal to the PCM. With the key on, engine off, slowly work the throttle from closed position to wide open throttle and back again. There shouldn’t be any breaks, spikes to ground, or dropouts in the waveform’s amplitude. Throttle Position SW Connect COM probe to the Sensor’s ground circuit, engine block, or negative battery post.
Sensor Tests Optical (CKP/CMP) Connect COM probe to the sensor’s ground circuit, engine block, or negative battery post. Connect CH1 probe to the sensor’s signal circuit to the PCM. Crank or start the engine. Let the engine idle, rev the engine, or drive the vehicle to make the driveability or emissions problem occur. Check the waveform for proper shape, frequency, and amplitude. Dual Trace Hall Eff Connect COM probe to the sensor’s ground circuit, engine block, or negative battery post.
Sensor Tests Hall Effect VSS Connect COM probe to the sensor’s ground circuit, engine block, or negative battery post. Connect CH1 probe to the crankshaft sensor’s signal circuit to the PCM. Connect CH1 probe to the sensor signal circuit to the PCM. As the wheels begin to spin, digital pulses should increase in frequency as wheel speed increases. Check the waveform for proper shape, frequency, and amplitude.
Sensor Tests Analog MAF Hot Wire Connect COM probe to the sensor’s ground circuit, engine block, or negative battery post. Connect CH1 probe to the sensor’s signal circuit to the PCM. Crank or start the engine, let the engine idle, rev the engine, or drive the vehicle to make the driveability or emissions problem occur. Check the waveform for proper amplitude at any given air flow rate. Analog MAF Vane Type Connect COM probe to the sensor’s ground circuit, engine block, or negative battery post.
Sensor Tests EGR Pressure/Flow Connect COM probe to the sensor’s ground circuit, engine block, or negative battery post. Connect CH1 probe to the sensor’s signal circuit to the PCM. Crank or start the engine, let the engine idle, rev the engine, or drive the vehicle to make the driveability or emissions problem occur. Check the waveform for proper amplitude at any given air flow rate.
Actuator Tests Throt. Body Inj TBI Connect the COM probe to the engine block, or negative battery post. Connect the CH1 probe to the injector control signal from the PCM (the pulsing side of the fuel injector). Operate the engine as needed to make the driveability or emissions problem occur.
Actuator Tests EGR Ctrl Solenoid Connect the COM probe to the engine block, or negative battery post. Connect the CH1 probe to the solenoid/ valve’s control signal from the PCM (the pulsing side of the solenoid/valve). Start the engine, Rev the engine, or drive the vehicle to make the driveability or emissions problem occur. Check the waveform for proper duty cycle, shape, frequency, and amplitude at any desired EGR flow rate.
Actuator Tests Canister Purge Ctrl Connect the COM probe to the engine block, or negative battery post. Connect the CH1 probe to the solenoid/ valve’s control signal from the PCM (the pulsing side of the solenoid/valve). Start the engine, drive the vehicle and accelerate to activate the canister purge system. Check the waveform for proper duty cycle, shape, frequency, and amplitude required to purge the canister.
Actuator Tests Secondary Ignition Connect LabScope KV Adapter to CH2. Connect Cylinder #1 Pickup to CH1. Connect the Ground Lead on the LabScope KV Adapter to a good engine ground source such as the negative battery post or engine block. Connect the LabScope KV adapter to the Ignition System. Connect the Cylinder #1 Pickup around #1 Sparkplug wire. With the key on, engine running, use the throttle or drive the vehicle to make a misfire or drivability problem occur.
Electrical Tests Apply Switch Connect COM probe to the switch’s ground circuit, engine block, or negative battery post. Connect the CH1 probe to the switch’s signal circuit. Make sure power is switched on in the circuit so that the sensor, device or circuit is operational. The waveform should stay in a predetermined voltage range for a given condition. Alt Field Ctrl Connect COM probe to the regulator ground circuit, engine block, or negative battery post.
Electrical Tests V Drop high current Connect COM probe to negative battery post or portion of circuit closest to battery ground. Connect CH1 probe to ground connector or test point of suspected circuit farthest away from battery negative post (NOTE: probes may be connected in opposite fashion to measure voltage drops in power circuits). Make sure power in circuit, so normal current is flowing through circuit. Check amplitude of signal.. It should generally not exceed 300mV.
Electrical Tests Audio Speaker Test Connect COM probe to the negative speaker circuit. Connect the CH1 probe to the positive speaker circuit. Turn the radio on and watch the DSO display. Amplitude, frequency, and shape will all vary according to the sound being produced. Frequency ranges from 16Hz to 20,000 Hz are normally detectable by the human ear. 12 V DC Switches Connect COM probe to the switch’s or accessory’s ground circuit, engine block, or negative battery post.
RS232 Communications The Ferret 91 is equipped with an RS232 port for easy communication with a variety of computers. WaveFile AutoPro™ is an automotive labscope software accessory and repair information resource. WaveFile AutoPro™ has an extensive library of automotive sensor and actuator waveforms, on-line diagnostic and repair procedures, and interactive computer-based training. It allows the user to transfer waveforms to and from the Ferret 91 with just the touch of a button.
Technical Support & Service Questions or inquiries about service can be answered by contacting Ferret at: (231) 627-5664, Fax: (231) 627-2727, Toll Free (800) 627-5655. When sending an item to the factory address it to: Ferret Instruments, Inc. 1310 Higgins Dr. Cheboygan, MI 49721-1061 Include a note describing the problem. Your local tool dealer may carry some replacement parts and have an alternate service program.
