What Does P0616 Mean?
P0616 indicates that the starter relay circuit voltage is low. The ECM/PCM has detected lower than expected voltage on the starter relay control or feedback circuit, which could mean the relay is not being fully energized or there is excessive resistance in the circuit. The driver may experience slow cranking, intermittent no-start, or the starter may not engage at all.
Common Causes
30%
High resistance in the starter relay circuit wiring — corroded connectors, damaged wires, or poor connections
25%
Weak or discharged battery not providing sufficient voltage to the relay circuit
20%
Failed starter relay with high internal resistance
15%
Poor ground connection in the starter relay circuit
10%
ECM/PCM internal relay driver not providing full ground signal
Diagnostic Steps
1
Measure battery voltage: should be 12.4-12.8V with engine off. If below 12.2V, charge and load test the battery. A weak battery can cause low voltage throughout the starting circuit.
2
Perform voltage drop tests on the starter relay circuit while cranking: measure voltage drop across the relay coil supply wire (should be below 0.2V), across the relay contacts (below 0.1V), and across the ground circuit (below 0.1V). High drops indicate resistance.
3
Check the starter relay socket for corrosion, burnt contacts, or loose fit. Clean the socket and relay pins with electrical contact cleaner. If the socket shows heat damage, replace the fuse/relay box.
4
Measure the ECM's ground output to the relay control pin during a cranking attempt — it should pull below 0.5V when commanded on. If higher, trace the ground wire from the relay to the ECM for high resistance.
5
Inspect battery cable ends and terminals for corrosion. Clean with a wire brush and retighten. Check the engine-to-body ground strap for tightness and corrosion.
Estimated Repair Cost
$30 - $400
Parts + labor, varies by vehicle and location
P0616 indicates that the starter relay circuit voltage is low. The ECM/PCM has detected lower than expected voltage on the starter relay control or feedback circuit, which could mean the relay is not being fully energized or there is excessive resistance in the circuit. The driver may experience slo...
The most common cause of P0616 (Starter Relay Circuit Low) is: High resistance in the starter relay circuit wiring — corroded connectors, damaged wires, or poor connections
Typical repair costs for P0616 range from $30 to $400, depending on the vehicle, location, and whether you do it yourself or go to a shop.
The vehicle may fail to start or crank slowly. While not immediately dangerous, being stranded is a risk. Low voltage in the starter circuit can also cause excessive current draw, potentially overheating wiring or the relay. Repair promptly to avoid being stranded.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P0616 to identify the root cause.
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Quick Info
Category
Powertrain
System
Starting System
Difficulty
Type
Generic (SAE)
Recommended Tools
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