CONTROL GP-TRANSMISSION 2983860 - Caterpillar

Service Procedure E
Magnetic Pickup Check
1. Connect a 6V7070 Multimeter (or a voltmeter of same accuracy) to electronic speed switch common terminal (ESS-3) and signal terminal (ESS-4). Set the meter voltage scale to a scale greater than 1.5 VAC. Start the engine and run at idle rpm or 600 rpm (whichever is greater).If the measured voltage is 1.5 VAC or more, the operation of the magnetic pickup is correct. If measured voltage is less than 1.5 VAC, go to Step 2.
The magnetic pickup is an important part of the ETR Shutoff Protection System. It is required for crank terminate, overspeed and governing. Be ready to take action when the magnetic pickup is disconnected.
2. Stop the engine. Disconnect the wiring from the magnetic pickup at the plug-in connector and connect the voltmeter to magnetic pickup connector terminals. Start the engine and run at idle rpm or 600 rpm (whichever is greater).If the measured voltage is 1.5 VAC or more, repair or replace the wiring between the magnetic pickup and the electronic speed switch. If the measured voltage is less than 1.5 VAC, go to Step 3.
Magnetic Pickup (Typical Illustration)
(1) Clearance dimension. (2) Locknut.3. Remove the magnetic pickup from the engine flywheel housing and turn the flywheel until a gear tooth is directly in the center of the threaded opening for the magnetic pickup. Install the magnetic pickup again in the threads of the flywheel housing.4. Turn (by hand) in a clockwise direction until the end of the magnetic pickup just makes contact with the gear tooth. Now turn the magnetic pickup back out 1/2 turn (180 degrees in the counterclockwise direction) to get the correct air gap [clearance dimension (1)]. Now tighten locknut (2) to a torque of 45 7 N m (33 5 lb ft). Do not let the magnetic pickup turn while locknut (2) is tightened.Do Step 2 again. If voltage is still less than 1.5 VAC, replace the magnetic pickup.Time Delay Relay
On/Off Time Delay (Relay)
On/Off Time Delay (Relay)Performance Check
A. Items Required For Check: 1. Battery or any DC source of 8 to 40 volts.2. Voltmeter (6V7070 Multimeter or one of same accuracy).3. Stop watch.B. Bench Or Installed Test.Connect or verify source voltage to relay terminals 8 (-) and 4 (+) [if bench testing, also connect positive (+) voltage to relay terminal 6]. All connections must be maintained until tests are complete. There will be voltage when the relay is closed. When relay is open, there will be no voltage [voltage may be positive (+) or negative (-) when relay is tested on engine; when bench testing, voltage will always be positive (+)].1. Use the voltmeter to verify chart that follows: 2. (a) Apply positive (+) source voltage to terminal 1 and immediately verify the chart that follows (do not leave voltage on terminal 1 for more than 60 seconds): (b) Remove positive (+) source voltage from terminal 1. Use a stop watch and check the time from the moment of removal to verify chart