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4.4 SensorsG
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4.4 Sensors (Continued)G
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4.6 Relays
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4.6 Relays (Continued)G
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4.7 Switches
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4.7 Switches (Continued)G
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4.8 Lamps and Indicators
The ªCruiseº lamp is controlled by the Body Control Module. The Diagnostic/Glow Plug lamp is
controlled by the Engine Control Module. The ªAlarm Setº lamp is controlled by the SKIM.
5.0 DISCLAIMERS, SAFETY, WARNINGS
5.1 Disclaimers
All information, illustrations, and specifications contained in this manual are based on the latest
information available at the time of publication. The right is reserved to make changes at any time
without notice.
5.2 Safety
5.2.1 Technician Safety Information
WARNING!!Engines produce carbon monoxide that is odorless, causes slower reaction time,
and can lead to serious injury. When the engine is operating, keep service areas WELL
VENTILATED or attach the vehicle exhaust system to the shop exhaust removal system.
Set the parking brake and block the wheels before testing or repairing the vehicle. It is especially
important to block the wheels on front-wheel drive vehicles; the parking brake does not hold the
drive wheels.
When servicing a vehicle, always wear eye protection, and remove any metal jewelry such as
watchbands or bracelets that might make an inadvertent electrical contact.
When diagnosing a powertrain system problem, it is important to follow approved procedures
where applicable. These procedures can be found in the service manual. Following these
procedures is very important to the safety of individuals performing diagnostic tests.
5.2.2 Vehicle Preparation for Testing
Make sure the vehicle being tested has a fully charged battery. If it does not, false diagnostic
codes or error messages may occur.
5.2.3 Servicing Sub-Assemblies
Some components of the powertrain system are intended to be serviced in assembly only.
Attempting to remove or repair certain system sub-components may result in personal injury
and/or improper system operation. Only those components with approved repair and installation
procedures in the service manual should be serviced.
5.2.4 DRBIIITSafety Information
WARNING: Exceeding the limits of the DRB multimeter is dangerous. It can expose you to
serious or possibly fatal injury. Carefully read and understand the cautions and the
specification limits.
²Follow the vehicle manufacturer's service specifications at all times.
²Do not use the DRB if it has been damaged.
²Do not use the test leads if the insulation is damaged or if metal is exposed.
²To avoid electrical shock, do not touch the test leads, tips, or the circuit being tested.
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²Choose the proper range and function for the measurement. Do not try voltage or current
measurements that may exceed the rated capacity.
²Do not exceed the limits shown in the table below:
FUNCTION INPUT LIMIT
Volts 0 - 500 peak volts AC
0 - 500 volts DC
Ohms (resistance)* 0 - 1.12 megohms
Frequency Measured
Frequency Generated0-10kHz
Temperature -58 - 1100É F
-50 - 600É C
* Ohms cannot be measured if voltage is
present. Ohms can be measured only in a
non-powered circuit.
²Voltage between any terminal and ground must not exceed 500v DC or 500v peak AC.
²Use caution when measuring voltage above 25v DC or 25v AC.
²The circuit being tested must be protected by a 10A fuse or circuit breaker.
²Use the low current shunt to measure circuits up to 10A. Use the high current clamp to
measure circuits exceeding 10A.
²When testing for the presence of voltage or current, make sure the meter is functioning
correctly. Take a reading of a known voltage or current before accepting a zero reading.
²When measuring current, connect the meter in series with the load.
²Disconnect the live test lead before disconnecting the common test lead.
5.3 Warnings
5.3.1 Vehicle Damage Warnings
Before disconnecting any control module, make sure the ignition is ``off''. Failure to do so could
damage the module.
When testing voltage or continuity at any control module, use the terminal side (not the wire end)
of the connector. Do not probe a wire through the insulation; this will damage it and eventually
cause it to fail because of corrosion.
Be careful when performing electrical tests so as to prevent accidental shorting of terminals. Such
mistakes can damage fuses or components. Also, other codes could be set, making diagnosis of
the original problem more difficult.
5.3.2 Road Testing a Complaint Vehicle
Some complaints will require a test drive as part of the repair verification procedure. The purpose
of the test drive is to try to duplicate the diagnostic code or symptom condition.
CAUTION: Before road testing a vehicle, be sure that all components are reassembled.
During the test drive, do not try to read the DRB screen while in motion. Do not hang the
DRB from the rear view mirror or operate it yourself. Have an assistant available to operate
the DRB.
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