OBD-II Diagnostic Trouble Code
P0560 — System Voltage Malfunction
P0560 indicates a system voltage malfunction: the ECM saw supply voltage outside its expected range or not plausible. It may relate to the charging system, battery, or the ECM's power and ground circuits.
Severity 4/5
Truck-relevant
Stop within 50 mi
Severity
Stop within 50 mi
System Voltage Malfunction
Code
P0560
Category
Powertrain
Subsystem
Network
Truck-relevant
Yes
What this means for truckers
P0560 — see above.
Before you replace parts — try this first
P0560 on the Network system is most often weak or failing batteries — not a dead part. On commercial diesels especially, work these in order before spending money on parts:
- Confirm the symptoms. Match what your truck is doing to the Symptoms section below. If the code is set but the symptoms are not there, clear the code and re-test after a drive cycle — it may not return.
- Clean and dry the sensor connector. Water, road salt, or oil seeping into a connector is the #1 fake sensor failure. Disconnect, look for green corrosion or moisture, spray with electrical contact cleaner, dry, reseat. Many faults clear here for $0.
- Inspect the wiring harness. Trace the wire from the sensor toward the ECM — look for chafing against the engine block, melted insulation near the turbo or exhaust, or pinch points where a clamp has rubbed through.
- Test the sensor before swapping it. Most Common Causes (below) list the expected voltage or resistance range — a $20 multimeter saves a $300 sensor swap that does not fix the problem.
- Only then, replace the part. Use the OEM or a tier-1 aftermarket. Cheap sensors throw the same code in two weeks.
Symptoms
Battery or charge warning light, dim lights, slow cranking, or erratic gauge and module behavior. Other codes may appear across modules. Severe cases cause no-start or stalling.
Common causes
- CommonWeak or failing batteries ($200–$900)
- CommonLoose or corroded battery cables or ground straps ($50–$300)
- OccasionalFailing alternator or regulator ($400–$1200)
- OccasionalPoor ECM power or ground connection ($100–$400)
How to fix
Load test batteries and check charging voltage at idle and 1500 RPM
When to use: First step
Clean and tighten all battery terminals, cable ends and frame/engine grounds
When to use: When voltage drop is found
Check voltage at the ECM power pins under load
When to use: When battery and alternator test good
Replace the alternator
When to use: When output is out of spec
Affects most
No specific vehicle pattern found in our complaint database. This code can appear on any vehicle that supports OBD-II diagnostics.
Related
- → Browse all DTC trouble codes
- → Decode a VIN to check codes for your truck
- → Owner-operator maintenance guides
- → P0500 — Vehicle Speed Sensor Malfunction
- → P0501 — Vehicle Speed Sensor Range/Performance
- → P0502 — Vehicle Speed Sensor Low Input
- → P0503 — Vehicle Speed Sensor Intermittent/Erratic/High
- → P0506 — Idle Control System RPM Lower Than Expected
Frequently Asked Questions
Can I drive with code P0560?
Drive with caution. P0560 is severity 4 — stop within ~50 miles. Most commercial diesel codes at this severity (turbo, fuel rail, transmission solenoid) can damage adjacent expensive components if left unrepaired. Get to a service location before highway-speed loads.
How much does it cost to fix P0560 on a commercial truck?
Total repair cost ranges $50–$1200 depending on the root cause. The cheapest fix is usually the first one listed below — Weak or failing batteries — which is also the most common. On commercial trucks the cost is usually higher than passenger vehicles due to part availability and shop labor rates ($120–185/hour at most truck shops, vs $90–130 at general auto shops). DIY-capable fixes (sensors, hoses, filters) are at the low end; major component replacements (turbo actuator, high-pressure fuel pump, transmission solenoid pack) are at the high end. Always diagnose with a scan tool BEFORE replacing parts — guessing wrong on a $1,500 turbo actuator when the actual issue was a $30 boost hose is a common expensive mistake.
Will P0560 fail a DOT inspection?
P0560 is generally not a direct DOT inspection fail item by itself. Inspectors focus on safety-critical systems (brakes, steering, tires, lights, hours-of-service). However, the check engine light alone can trigger additional inspection scrutiny. Best practice: fix the code and clear it before a planned inspection.
What's the difference between P0560 and related codes?
P0560 is closely related to: P0500 (Vehicle Speed Sensor Malfunction), P0501 (Vehicle Speed Sensor Range/Performance), P0502 (Vehicle Speed Sensor Low Input), P0503 (Vehicle Speed Sensor Intermittent/Erratic/High). These codes share the same subsystem (network) and often appear together. If you see this code, scan for the full code list — fixing the root cause usually clears multiple companion codes at once. If only P0560 is set without the companions, the issue is more isolated.
How do I prevent P0560 from coming back after a repair?
For P0560 (System Voltage Malfunction), prevention centers on the network system. Pay attention to ground connections at every PM — bad grounds are 70% of communication codes. Inspect harness routing for chafe points. Don't disconnect modules with the key on.