Vehicle Damage Warnings
Vehicle Preparation for TestingMake sure the vehicle being tested has a fully charged battery. If it does not, false diagnostic codes or error messages may occur.
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 should be serviced.
Disconnecting PCM Connectors
Whenever any connector on the PCM is disconnected, the ignition switch must be in the "OFF" position for a minimum of 5 seconds before connector removal.
It has been found under certain key "ON" or momentary key "OFF" conditions, when the black connector is unplugged, the PCM may attempt to write information to the EEPROM processor within the PCM. Sometimes this inadvertent write will set the target charging voltage to 0 (zero) volts. The result will prevent the charging system from charging the battery.
If this occurs, the only correction is PCM replacement.
DRBIII Safety 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.
Follow the vehicle manufacturer's service specifications at all times.
- Do not use the DRB if it has been damaged.
- Do not use the test leads if the insulation is damaged or if metal is exposed.
- To avoid electrical shock, do not touch the test leads, tips, or the circuit being tested.
- Choose the proper range and function for the measurement. Do not try voltage or current measurements that may exceed the rated capacity.
- Do not exceed the limits shown in the table below:
FUNCTION INPUT LIMIT
Volts 0 - 500 peak volts A/C
0 - 500 volts DC
Ohms (resistance)* 0 - 1.12 megohms
Frequency Measured 0 - 10 kHz
Frequency Generated 0 - 10 kHz
Temperature -58 - 110°F
-50 - 60°C
* Ohms cannot be measured if voltage is present.
* Ohms can be measured only in a non-powered circuit.
^ Voltage between any terminal and ground must not exceed 500v DC or 500v peak AC. Use caution when measuring voltage above 25v DC or 25v AC.
^ The circuit being tested must be protected by a 10A fuse or circuit breaker.
^ Use the low current shunt to measure circuits up to 10A. Use the high current clamp to measure circuits exceeding 10A.
^ When 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.
^ When measuring current, connect the meter in series with the load.
^ Disconnect the live test lead before disconnecting the common test lead.
^ When using the meter function, keep the DRB away from spark plug or coil wires to avoid measuring error from outside interference.
Road Test Warnings
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.
Vehicle Damage Cautions
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, a second code could be set, making diagnosis of the original problem more difficult.
Electronic Pinion Factor Warning
The pinion factor must be set for all new transmission control modules. If the pinion factor is not set or if it is set incorrectly, any speed-related accessories will not operate or will operate inaccurately. This includes the speedometer, speed control, rolling door locks, and other devices that are operated by the powertrain and body control modules.