Charging System Operation Test
Charging System Operation Test
For a complete wiring diagram, refer to.
Test Step 1 - Generator Full Field Test
• Diagnose and resolve any generator sense or field control circuit DTCs before proceeding with this test.
• Start the engine and allow it to reach operating temperature.
When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts, or fan. Do not wear loose clothing. Failure to follow these instructions can result in personal injury or death.
• With the scan tool, perform the Generator Full Field Test. Follow the instructions displayed on the scan tool.
• Monitor the battery voltage and the generator sense voltage on the scan tool while performing the test.
• With the engine running, the difference between the battery voltage and the generator sense voltage should be less than 0.2 volts.
• With the generator field fully actuated, the battery voltage should be more than 14.0 volts.
• With the generator field actuated off, the battery voltage should be less than 13.0 volts, and eventually drop as battery load is increased.
Did the system voltage change as described above during the generator full field test?
Yes
• Test complete.
No
• Go to Test Step 2
Test Step 2 - Charging System Inspection
• Inspect and test the battery.
• Inspect the generator drive belt for proper alignment and adjustment.
• Inspect the vehicle for aftermarket accessories that may exceed the generator system output.
• Inspect the fuses in the IPM. If an open fuse is found, use the wire diagram/schematics as a guide and inspect the wiring and connectors for a damaged or shorted circuit.
Were any problems found?
Yes
• Repair as necessary.
No
• Go to Test Step 3
Test Step 3 - Battery Positive Circuit High Resistance
• Make sure all testing equipment and cables are clear of any engine parts before starting the engine.
• Start the engine.
When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts, or fan. Do not wear loose clothing. Failure to follow these instructions can result in personal injury or death.
• Measure the voltage between the B (+) terminal at the generator and the battery positive post.
Is the voltage less than 0.4 volts?
Yes
• Go to Test Step 4
No
• Repair the battery positive circuit between the generator and battery for high resistance.
• Perform the PCM Verification Test. Refer to => [ PCM Verification Test ] PCM Verification Test.
Test Step 4 - Generator Case Ground High Resistance
• Make sure all testing equipment and cables are clear of any engine parts before starting the engine.
• Start the engine.
When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts, or fan. Do not wear loose clothing. Failure to follow these instructions can result in personal injury or death.
• Measure the voltage between the generator case and the battery negative post.
Is the voltage less than 0.1 volt?
Yes
• Go to Test Step 5
No
• Repair the generator case ground for high resistance.
• Perform the PCM Verification Test. Refer to => [ PCM Verification Test ] PCM Verification Test.
Test Step 5 - Fused B (+) Circuit High Resistance
• Turn the ignition off.
Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install Miller Special Tool #8815 along with the #8815-1 to perform the diagnosis.
• Using a voltmeter, perform a voltage drop test by probing the battery positive terminal and the appropriate terminals of the special tool #8815. Make sure the voltmeter leads are connected so that positive polarity is displayed on the voltmeter.
When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts, or fan. Do not wear loose clothing. Failure to follow these instructions can result in personal injury or death.
• Start the engine.
Is the voltage less than 0.5 volts?
Yes
• Go to Test Step 6
No
• Repair the fused B (+) circuits for high resistance.
• Perform the PCM Verification Test. Refer to => [ PCM Verification Test ] PCM Verification Test.
Test Step 6 - Generator Sense Circuit High Resistance
• Turn the ignition off.
Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install Miller Special Tool #8815 along with the #8815-1 to perform the diagnosis.
• Using a voltmeter, perform a voltage drop test by backprobing the generator sense circuit at the generator harness connector and probing the appropriate terminal of the special tool #8815. Make sure the voltmeter leads are connected so that positive polarity is displayed on the voltmeter.
When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts, or fan. Do not wear loose clothing. Failure to follow these instructions can result in personal injury or death.
• Start the engine.
Is the voltage less than 0.5 volts?
Yes
• Go to Test Step 7
No
• Repair the generator sense circuit for high resistance.
• Perform the PCM Verification Test. Refer to => [ PCM Verification Test ] PCM Verification Test.
Test Step 7 - Generator Field Control Circuit High Resistance
• Turn the ignition off.
Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install Miller Special Tool #8815 along with the #8815-1 to perform the diagnosis.
• Using a voltmeter, perform a voltage drop test by backprobing the generator field control circuit at the generator harness connector and probing the appropriate terminal of the special tool #8815. Make sure the voltmeter leads are connected so that positive polarity is displayed on the voltmeter.
When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts, or fan. Do not wear loose clothing. Failure to follow these instructions can result in personal injury or death.
• Start the engine.
Is the voltage less than 0.5 volts?
Yes
• Go to Test Step 8
No
• Repair the generator field control circuit for high resistance.
• Perform the PCM Verification Test. Refer to => [ PCM Verification Test ] PCM Verification Test.
Test Step 8 - Generator
• Turn the ignition off.
• Disconnect the generator harness connector.
• Connect a 12 volt test lamp connected between ground and the generator field control circuit in the generator harness connector.
• Turn the ignition on.
• With the scan tool, actuate the Alternator Field Control State to toggle.
• The test lamp should toggle on and off with the actuation.
• If a DTC is active, the actuation test may not be allowed by the PCM. If may be necessary to clear DTCs before starting the actuation.
Does the test lamp illuminate on and off with the actuation?
Yes
• Replace the generator.
• Perform the PCM Verification Test. Refer to => [ PCM Verification Test ] PCM Verification Test.
No
• Go to Test Step 9
Test Step 9 - Generator Field Control Circuit Shorted to Voltage
• Turn the ignition off.
• Disconnect the PCM connector.
• Turn the ignition on.
• Measure the voltage of the generator field control circuit in the Generator harness connector.
Is there any voltage present?
Yes
• Repair the generator field control circuit for a short to voltage.
• Perform the PCM Verification Test. Refer to => [ PCM Verification Test ] PCM Verification Test.
No
• Go to Test Step 10
Test Step 10 - Generator Field Control Circuit Shorted to Ground
• Turn the ignition off.
• Measure the resistance between ground and the generator field control circuit in the generator harness connector.
Is the resistance less than 100 ohms?
Yes
• Repair the generator field control circuit for a short to ground.
• Perform the PCM Verification Test. Refer to => [ PCM Verification Test ] PCM Verification Test.
No
• Go to Test Step 11
Test Step 11 - Generator Field Control Circuit Open or High Resistance
Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals, resulting in poor terminal to pin connection. Install Miller Special Tool #8815 to perform diagnosis.
• Measure the resistance of the generator field control circuit between the generator harness connector and the appropriate terminal of special tool #8815.
Is the resistance less than 5.0 ohms?
Yes
• Go to Test Step 12
No
• Repair the generator field control circuit for an open circuit or high resistance.
• Perform the PCM Verification Test. Refer to => [ PCM Verification Test ] PCM Verification Test.
Test Step 12 - Check the PCM Power and Ground Circuits
• Perform the diagnostic procedure for checking the PCM power and ground circuits.
Were any problems found?
Yes
• Repair the PCM power and ground circuits as necessary.
• Perform the PCM Verification Test. Refer to => [ PCM Verification Test ] PCM Verification Test.
No
• Go to Test Step 13
Test Step 13 - Powertrain Control Module
• Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the generator and the PCM.
• Look for any chafed, pierced, pinched, or partially broken wires.
• Look for broken, bent, pushed out or corroded terminals.
• Refer to any TSBs that may apply.
Were any problems found?
Yes
• Repair as necessary.
• Perform the PCM Verification Test. Refer to => [ PCM Verification Test ] PCM Verification Test.
No
• Replace and program the PCM.
• Perform the PCM Verification Test. Refer to=> [ PCM Verification Test ] PCM Verification Test.