The P0616 code indicates that the engine control module (PCM) has detected a voltage level that is too low in the starter relay control circuit. This typically means the circuit is grounded or open, preventing the PCM from properly triggering the starter motor.
The relay internal coil or contacts have failed, preventing the circuit from completing.
Chafed, broken, or corroded wires in the starter relay circuit causing a short to ground.
Oxidation or moisture in the relay socket or connector pins increasing resistance and dropping voltage.
An internal short within the starter solenoid can occasionally pull the control circuit voltage low.
A failure in the driver circuit within the engine computer, though this is the least common cause.
Not necessarily. P0616 refers to the electrical control circuit that activates the starter, not the mechanical operation of the motor itself.
No. While the PCM is listed as a cause, it is rarely the source of this error. Most P0616 issues are resolved by replacing the relay or repairing wiring.
A completely dead battery will prevent starting, but P0616 is specifically triggered by a voltage anomaly in the control circuit relative to the PCM's reference voltage.