What does it mean?
This generic powertrain/engine diagnostic code generally applies to all 1996 vehicles, including but not limited to Kia, Hyundai, Jeep, Mercedes, Dodge, Ford, and GM vehicles.
The PCM controls the charging system to some extent on these vehicles. The PCM can control the charging system by controlling a power supply or ground circuit to the voltage regulator inside the alternator.
The Powertrain Control Module (PCM) monitors the ignition power supply circuit to determine if the charging system is operating. If the voltage is too high or too low, a trouble code will be set. If voltage is not present when it should be, a trouble code will be set. This is strictly an electrical issue.
Troubleshooting steps may vary depending on the manufacturer, the type of charging system control, and the wire colors.
Symptoms
Symptoms of a P0561 engine code may include:
Malfunction Indicator Light illuminated
Red battery light illuminated
Transmission may not shift
Engine may not start or if it starts, it may stall and die
Reduced fuel economy
Causes
Causes
Possible causes for this code being set are:
High resistance in the cable between the alternator and the battery – possible
High resistance / open circuit between the alternator and the control module – possible
Faulty alternator – most common
Failed PCM – unlikely
Diagnostic and Repair Procedures
A good starting point is always to check the Technical Service Bulletins (TSBs) for your particular vehicle. Your issue may be a known problem with a known fix issued by the manufacturer and can save you time and money when diagnosing.
The most common cause of this code is low battery voltage / a disconnected battery / a malfunctioning charging system (faulty alternator). While we’re on the subject, let’s not forget to check the most overlooked part of the charging system, the alternator belt!
First, check the charging system. Start the vehicle. Turn on the headlights and the blower fan on high speed to load the electrical system. Using a Digital Volt Ohm Meter (DVOM), check the battery voltage. It should be between 13.2 volts and 14.7 volts. If the voltage is well below 12 volts or above 15.5 volts, diagnose the charging system, focusing primarily on the alternator. If in doubt, have the battery, starting, and charging system tested at a local parts store/auto repair shop. Most will perform this service for a small fee, if not for free, and will usually give you a printout of the test results.
If the voltage was correct and you have a scan tool, clear the diagnostic codes from the memory and see if this code returns. If it does not, it is more than likely that this code is intermittent or is a history/memory code and no further diagnosis is required.
If the P0561 code returns, locate the PCM on your specific vehicle. Once located, visually inspect the connectors and wiring. Look for chafing, rubbing, bare wires, burns, or melted plastic. Disconnect the connectors and carefully inspect the terminals (the metal parts) inside the connectors. See if they look burned or have a greenish tint indicating corrosion. Use electrical contact cleaner and a plastic bristle brush if cleaning the terminals is necessary. Let it dry and apply electrical grease where the terminals make contact.
Next, clear the diagnostic codes from the memory with the scan tool and see if this code returns. If it does not, the connections were likely your problem.
If the P0561 code returns, we will need to check the voltages at the PCM. First, disconnect the negative battery cable at the battery. Then, disconnect the wiring harness going to the PCM. Reconnect the battery cable. Turn the ignition on. With a DVOM, test the PCM ignition power supply circuit (red lead to the PCM ignition power supply circuit, black lead to a good ground). If there is less than battery voltage on this circuit, repair the wiring between the PCM and the ignition switch.
If that checks out, verify that you have a good ground at the PCM. Connect a test light to the positive 12V battery (red terminal) and touch the other end of the test light to the ground circuit going to the PCM ignition power supply circuit ground. If the test light does not illuminate, that would indicate the circuit problem. If it lights up, wiggle the wiring harness going to the PCM to see if the test light flickers, indicating an intermittent connection.
If all previous tests have passed and you continue to get a P0561, this would most likely indicate a faulty PCM. If in doubt, seek assistance from a qualified automotive diagnostician. PCMs need to be programmed or calibrated to the vehicle in order to be installed correctly.