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Charging System No Code Test

  1. Verify battery condition. Charge or replace battery as necessary. Inspect generator belt tension and condition. Replace generator belt as necessary. Start engine. Turn on all accessories. Set engine speed to 2000 RPM for 30 seconds, then return to idle. Using scan tool, check for Diagnostic Trouble Codes (DTCs). See DIAGNOSTIC TROUBLE CODE IDENTIFICATION  table under SELF-DIAGNOSTIC SYSTEM. If any charging system DTCs are set, perform appropriate test under DIAGNOSTIC TESTS  . If no charging system DTCs are set, go to next step.
  2. Turn ignition on, with engine off. Using scan tool, read and record battery voltage. Using a voltmeter, check voltage between battery positive terminal and battery negative terminal. If the 2 voltage readings are within one volt, go to next step. If the 2 voltage readings vary more than one volt, go to step  9 .
  3. Using a voltmeter, check voltage between generator B+ terminal located on rear of generator and battery positive terminal. Ensure voltmeter wires are clear of moving engine parts. Start engine and observe voltmeter. If voltage is 0.4 volt or less, go to next step. If voltage is more than 0.4 volt, repair high resistance between generator B+ terminal and battery positive terminal. Perform CHARGING SYSTEM TEST  under VERIFICATION TESTS.
    4. NOTE: The generator field source circuit changes wire color from Light Blue/Red wire at PCM connector C3 terminal No. 25 to White/Red wire at generator field harness connector terminal No. 1.
  4. Using scan tool, record DTCs and freeze frame data. Clear all DTCs. Check all connectors for corrosion and spread terminals. Repair as necessary. Using scan tool, actuate generator field driver circuit. Using a voltmeter, check voltage at generator field source terminal No. 1, located on rear of generator. If voltage is more than 10 volts, go to next step. If voltage is 10 volts or less, repair generator field source circuit. Perform CHARGING SYSTEM TEST  under VERIFICATION TESTS.
  5. Start engine. Using a voltmeter, check voltage between generator case and battery negative terminal. If voltage is 0.1 volt or less, go to next step. If voltage is more than 0.1 volt, repair high resistance between generator case and battery negative terminal. Perform CHARGING SYSTEM TEST  under VERIFICATION TESTS.
  6. Turn ignition off. Disconnect generator field harness connector. Measure resistance between field terminals (component side). If resistance is 15 ohms or less, go to next step. If resistance is 15 ohms or more, replace generator. Perform CHARGING SYSTEM TEST  under VERIFICATION TESTS.
  7. Turn ignition off. Disconnect PCM harness connectors. Disconnect field harness connector on rear of generator. Measure resistance of Dark Green wire between PCM connector C2 terminal No. 10 and generator 2-pin connector terminal No. 2. See Figure and Figure . If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open generator field driver circuit. Perform CHARGING SYSTEM TEST  under VERIFICATION TESTS.
  8. If no other problems were found, replace PCM. Perform TEST VER-2  under VERIFICATION TESTS.
  9. Turn ignition off. Inspect generator belt tension and condition. Repair as necessary. If no problem is found, go to next step.
  10. Turn ignition on. Using scan tool, actuate generator field. Using test light, backprobe generator field driver terminal No. 2 (Dark Green wire). See Figure . Test light should flash on and off every 1.4 seconds. While observing test light, wiggle field terminal wiring harness back to Powertrain Control Module (PCM). If any interruption of voltage cycling occurred, repair wiring harness where wiggling caused failure. Perform CHARGING SYSTEM TEST  under VERIFICATION TESTS. If wiggling did not interrupt voltage cycling, go to next step.
  11. Start engine. Turn on all accessories. Raise engine speed to 2000 RPM for 30 seconds. Return engine speed to idle. Using scan tool, check for DTCs. See DIAGNOSTIC TROUBLE CODE IDENTIFICATION  table under SELF-DIAGNOSTIC SYSTEM. If any charging system DTCs are set, perform appropriate test under DIAGNOSTIC TESTS  . If no charging system DTCs are set, test is complete.
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