Sierra Classic 2500 4WD V8-6.0L (2007)
may be recorded in each snapshot. The Scan Tool has the ability to store 2 snapshots. The ability to record 2 snapshots allows comparing hot versus cold
and good versus bad vehicle scenarios. The snapshots are stored on a first-in, first-out basis. If a third snapshot is taken, the first snapshot stored in the
memory will be lost.
Snapshots can be 1 of 2 types:
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Snapshot - taken from the Snapshot menu choice
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Quick Snapshot - taken from the Data Display soft key choice, does not contain DTC information
When a snapshot is taken, it is recorded on the memory card and may contain as many as 1200 frames of information. Because the snapshot is recorded
onto the memory card, snapshots are not lost if the Scan Tool is powered down.
The snapshot replay screen has a plot soft key that can be of great value for intermittent diagnosis. The snapshot plot feature can help you to quickly
determine if a sensor is outside of its expected values by plotting 3 parameters at a time. The data will be displayed both graphically and numerically
showing the minimum and maximum values for all frames captured. This is helpful, especially if the fault occurs only once and does not set a DTC.
Testing for a Short to Voltage
TESTING FOR A SHORT TO VOLTAGE
NOTE: Refer to Test Probe Notice.
The following procedure tests for a short to voltage in a circuit.
1. Set the rotary dial of the DMM to the V (DC) position.
2. Connect the positive lead of the DMM to one end of the circuit to be tested.
3. Connect the negative lead of the DMM to a good ground.
4. Turn ON the ignition and operate all accessories.
5. If the voltage measured is greater than 1 volt, there is a short to voltage in the circuit.
Testing for Continuity
TESTING FOR CONTINUITY
NOTE: Refer to Test Probe Notice.
The following procedures verify good continuity in a circuit.
With a DMM
1. Set the rotary dial of the DMM to the ohm position.
2. Disconnect the power feed (i.e. fuse, control module) from the suspect circuit.
3. Disconnect the load.
4. Press the MIN MAX button on the DMM.
5. Connect one lead of the DMM to one end of the circuit to be tested.
6. Connect the other lead of the DMM to the other end of the circuit.
7. If the DMM displays low or no resistance and a tone is heard, the circuit has good continuity.
With a Test Lamp
IMPORTANT: Only use the test lamp procedure on low impedance power and ground circuits.
1. Remove the power feed (i.e. fuse, control module) from the suspect circuit.
2. Disconnect the load.
3. Connect one lead of the test lamp to one end of the circuit to be tested.
4. Connect the other lead of the test lamp to battery positive voltage.
5. Connect the other end of the circuit to ground.
6. If the test lamp illuminates (full intensity), then the circuit has good continuity.
Testing for Electrical Intermittents
TESTING FOR ELECTRICAL INTERMITTENTS
TOOLS REQUIRED
J 39200 Digital Multimeter
Perform the following procedures while wiggling the harness from side to side. Continue this at convenient points (about 6 inches apart) while
watching the test equipment.
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Testing for Short to Ground
