Express 2500 V8-6.6L DSL Turbo (2010)
Testing for Electrical Intermittents
Testing for Electrical Intermittents
Special Tools
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 (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic
Procedures/Circuit Testing/Testing for Short to Ground)
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Testing for Continuity (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Circuit
Testing/Testing for Continuity)
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Testing for a Short to Voltage (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic
Procedures/Circuit Testing/Testing for a Short to Voltage)
If the fault is not identified, perform the procedure below using the MIN MAX feature on the J 39200 DMM. This feature allows you to manipulate the
circuit without having to watch the J 39200. The J 39200 will generate an audible tone when a change is detected.
Note: The J 39200 must be used in order to perform the following procedure since the J 39200 can monitor current, resistance or voltage while
recording the minimum (MIN), and maximum (MAX) values measured.
1. Connect the J 39200 to both sides of a suspected connector (still connected), or from one end of a suspected circuit to the other. Refer to
Troubleshooting with a Digital Multimeter (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic
Procedures/Circuit Testing/Troubleshooting with a Digital Multimeter) for information on connecting the J 39200 to the circuit.
2. Set the rotary dial of the J 39200 to the V (AC) or V (DC) position.
3. Press the range button of the J 39200 in order to select the desired voltage range.
4. Press the MIN MAX button of the J 39200. The J 39200 displays 100 ms RECORD and emits an audible tone (beep).
Note: The 100 ms RECORD mode is the length of time an input must stay at a new value in order to record the full change.
5. Simulate the condition that is potentially causing the intermittent connection, either by wiggling the connections or the wiring, test driving, or
performing other operations. Refer to Inducing Intermittent Fault Conditions (See: Testing and Inspection/Component Tests and General
Diagnostics/General Electrical Diagnostic Procedures/Circuit Testing/Inducing Intermittent Fault Conditions).
6. Listen for the audible Min Max Alert which indicates that a new minimum or maximum value has been recorded.
7. Press the MIN MAX button once in order to display the MAX value and note the value.
8. Press the MIN MAX button again in order to display the MIN value and note the value.
9. Determine the difference between the MIN and MAX values.
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If the variation between the recorded MIN and MAX voltage values is 1 V or greater an intermittent open or high resistance condition exists.
Repair the condition as necessary.
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If the variation between the recorded MIN and MAX voltage values is less than 1 V, an intermittent open or high resistance condition does not
exist.
Testing for Intermittent Conditions and Poor Connections
Testing for Intermittent Conditions and Poor Connections
Special Tools
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J 35616 GM-Approved Terminal Test Kit
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J-38125 Terminal Repair Kit
When the condition is not currently present, but is indicated in DTC history, the cause may be intermittent. An intermittent may also be the cause when
there is a customer complaint, but the symptom cannot be duplicated. Refer to the Symptom Table of the system that is suspect of causing the condition
before trying to locate an intermittent condition.
Most intermittent conditions are caused by faulty electrical connections or wiring. Inspect for the following items:
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Wiring broken inside the insulation
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Poor connection between the male and female terminal at a connector
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Poor terminal to wire connection-Some conditions which fall under this description are poor crimps, poor solder joints, crimping over the wire
insulation rather than the wire itself, and corrosion in the wire to terminal contact area, etc.
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Pierced or damaged insulation can allow moisture to enter the wiring causing corrosion. The conductor can corrode inside the insulation, with little
