Test NTC-19: Checking Charging System

NOTE: Possible causes are: DTCs present, generator field terminals intermittently defective, generator ground circuit high resistance, B+ circuit high resistance, defective Powertrain Control Module (PCM) or defective generator belt.

NOTE: Ensure battery is in good condition and fully charged before proceeding with test procedure.

NOTE: After making any repair during this testing procedure, perform TEST VER-3A: CHARGING VERIFICATION .

Inspect generator belt for damage and proper adjustment. If generator belt is in good condition and properly adjusted, go to next step. If generator belt is not in good condition or not properly adjusted, repair as necessary.
Start engine and let idle. Using scan tool, set engine speed to 1600 RPM for 30 seconds and then return engine to idle. Using scan tool, check for DTCs. If no DTCs exist for charging system, go to next step. If any DTCs for charging system exists, proceed to appropriate DTC test.
Turn ignition off. Turn ignition on. Using scan tool, actuate generator field driver. Using voltmeter, backprobe between ground and terminal No. 2 (Dark Green wire) at generator harness connector. See Figure or Figure . Voltage should cycle from no voltage to battery voltage every 1.4 seconds. While monitoring voltage, wiggle wiring harness and connectors between generator and Powertrain Control Module (PCM), and between generator and Auto Shutdown (ASD) relay. PCM is located to left of Power Distribution Center (PDC) in engine compartment, next to air cleaner. ASD relay is located in power distribution center at driver's side front corner of engine compartment, near air cleaner assembly. If no interruption of the voltage cycle exists, go to next step. If interruption of the voltage cycle exists, repair wiring harness where wiggling caused problem to appear.
Using scan tool, check for DTCs. If no DTCs exist for charging system, go to next step. If any DTCs for charging system exists, proceed to appropriate DTC test.
Turn ignition off. Measure voltage between case of generator and negative battery terminal. Start engine. If voltage is .1 volt or less, go to next step. If voltage is more than .1 volt, repair generator for high resistance between generator case and negative battery terminal.
Turn ignition off. Measure voltage between positive battery terminal and positive battery terminal on rear of generator. Start engine. If voltage is .4 volt or less, go to next step. If voltage is more than .4 volt, repair high resistance between positive battery terminal and positive battery terminal on rear of generator.
Turn ignition off. Turn ignition on. Using scan tool, read battery voltage. Record battery voltage displayed on scan tool. Measure voltage between positive and negative battery terminals. Compare the 2 battery voltage readings. If difference between voltage readings is one volt or more, go to next step. If difference between voltage readings is less than one volt, test is complete.
Turn ignition off. Disconnect Powertrain Control Module (PCM) harness connectors. PCM is located to left of Power Distribution Center (PDC) in engine compartment, next to air cleaner. Inspect harness connectors and clean/repair as necessary. Measure voltage between ground and terminal No. 46 (Red/Tan wire) at PCM harness connector C2. See Figure . If voltage is not within one volt of the voltage displayed on scan tool in step 8) , replace PCM. After replacing PCM, PCM MUST be reprogrammed. See POWERTRAIN CONTROL MODULE under PROGRAMMING. If voltage is within one volt of the voltage displayed on scan tool in step 8) , repair high resistance on Red/Tan wire between PCM, fuse No. 5 (20-amp) and the battery. Fuse No. 5 is located in power distribution center at driver's side front corner of engine compartment, near air cleaner assembly.