Sierra Classic 2500 4WD V8-6.0L (2007)
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There are only a few situations where reprogramming a control module is appropriate:
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A new service control module is installed.
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A control module from another vehicle is installed.
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Revised software/calibration files have been released for this vehicle.
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IMPORTANT: DO NOT re-program the control module with the SAME software/calibration files that are already present in the control module.
This is not an effective repair for any type of concern.
Verify that the control module contains the correct software/calibration. If incorrect programming is found, reprogram the control module with the
most current software/calibration. Refer to Control Module References for replacement, setup, and programming. See: Testing and
Inspection/Programming and Relearning
Testing for Short to Ground
TESTING FOR SHORT TO GROUND
NOTE: Refer to Test Probe Notice.
The following procedures test for a short to ground in a circuit.
With a DMM
1. Remove the power feed (i.e. fuse, control module) from the suspect circuit.
2. Disconnect the load.
3. Set the rotary dial of the DMM to the ohm position.
4. Connect one lead of the DMM to one end of the circuit to be tested.
5. Connect the other lead of the DMM to a good ground.
6. If the DMM does NOT display infinite resistance (OL), there is a short to ground in the circuit.
With a Test Lamp
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 battery positive voltage.
4. Connect the other lead of the test lamp to one end of the circuit to be tested.
5. If the test lamp illuminates, there is a short to ground in the circuit.
Fuse Powering Several Loads
1. Review the system schematic and locate the fuse that is open.
2. Open the first connector or switch leading from the fuse to each load.
3. Connect a DMM across the fuse terminals (be sure that the fuse is powered).
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When the DMM displays voltage the short is in the wiring leading to the first connector or switch.
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If the DMM does not display voltage.
4. Close each connector or switch until the DMM displays voltage in order to find which circuit is shorted.
Troubleshooting with a Digital Multimeter
TROUBLESHOOTING WITH A DIGITAL MULTIMETER
NOTE: Refer to Test Probe Notice.
IMPORTANT: Circuits which include any solid state control modules, such as the powertrain control module (PCM), should only be tested with a 10
megohm or higher impedance digital multimeter such as the J 39200 Digital Multimeter (DMM).
The J 39200 instruction data is a good source of information and should be read thoroughly upon receipt of the DMM as well as kept on hand for future
reference.
A DMM should be used instead of a test lamp in order to test for voltage in high impedance circuits. While a test lamp shows whether voltage is present
if the impedance is low enough, a DMM indicates how much voltage is present. In other words, if there is not enough current, the test lamp will not
illuminate even though voltage is present.
The ohmmeter function on a DMM shows how much resistance exists between 2 points along a circuit. Low resistance in a circuit means good
continuity.
IMPORTANT: Disconnect the power feed from the suspect circuit when measuring resistance with a DMM. This prevents incorrect readings. DMMs
apply such a small voltage to measure resistance that the presence of voltages can upset a resistance reading.
Diodes and solid state components in a circuit can cause a DMM to display a false reading. To find out if a component is affecting a measurement take a
reading once, then reverse the leads and take a second reading. If the readings differ the solid state component is affecting the measurement.
