DTC P0562: CHARGING SYSTEM VOLTAGE TOO LOW

Monitor & Set Conditions

Charging system voltage is monitored when ignition is on. DTC may be stored if battery supply voltage (B+ circuit) at Engine Control Module (ECM) is less than 6 volts.

Possible Causes

• PCM Codes
• ECM
• Fused B+ Circuit Open
• Ground Circuit Open
• High Battery Cable Resistance
• Low Battery Current
• Low Battery Voltage

Testing

1. Turn ignition on with engine off. Using DRBIII(R) scan tool, check for PCM DTCs. If DTC P1682 does not exist, go to next step. If DTC P1682 exists, perform DTC P1682: CHARGING SYSTEM VOLTAGE TOO LOW in appropriate GENERATORS & REGULATORS article in STARTING & CHARGING SYSTEMS.

2. Check generator belt condition and tension. Adjust or replace generator belt as necessary. Check for high resistance in battery cables. If either battery cable has a voltage drop of .2 volt or greater, replace battery cable. If generator belt and battery cables are okay, go to next step.

3. Using DVOM, measure voltage between battery terminals. If voltage is 12 volts or greater, go to next step. If voltage is less than 12 volts, recharge or replace battery as necessary.

4. Turn ignition off. Disconnect ECM harness connector. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. Connect a test light between ground and terminals No. 48 and 50 (Red/White wires) on ECM harness connector. These are the fused B+ circuits to ECM. If test light illuminates brightly at both terminals, go to next step. If test light does not illuminate brightly at both terminals, repair open in fused B+ circuit.

5. Perform starter draw test with starter installed. Starter draw should be 450-700 amps. If starter draw is not within specification, repair or replace starter. If starter draw is within specification, using DVOM, measure voltage between battery terminals while cranking engine. If voltage is greater than 6.2 volts while cranking engine, go to next step. If voltage is 6.2 volts or less while cranking engine, recharge or replace battery.

6. Turn ignition off. Ensure ECM harness connector is disconnected. Connect a test light between battery voltage and terminals No. 30 and 49 (Black/Tan wires) on ECM harness connector. These are the ECM ground circuits. If test light illuminates brightly at both terminals, replace and program ECM. See appropriate REMOVAL, OVERHAUL & INSTALLATION article. If test light does not illuminate brightly at both terminals, repair open ground circuit on Black/Tan wire between ECM and ground connection. Ground connection is located at ground connection for negative battery terminal.