What to do if your fuel pump relay fails?
Pull out the relay and visually inspect the terminals and socket; for signs of corrosion and overheating. Because, corrosion and overheating can prevent, proper current flow and indicates problems. Clean corroded terminals and socket with, electrical contact cleaner. Next, check all fuses before any repairs.
How many pins does a fuel pump relay have?
The fuel pump relay does often have 4 pins, and in this case, it is often easy. If your relay has more pins and not the same numbers mentioned here, you need to check a wiring diagram. Lift it and check under it for the numbers 30, 85, 86, and 87. If you locate these numbers, you can put the fuel pump relay back.
Is the fuel pump relay controlled by the PCM?
Consequently, the fuel pump relay is usually controlled by, the ignition or powertrain control module (PCM). As a result, when switched on, the fuel pump relay; will provide current to the fuel pump, so that it may function. Therefore, any faults with it, can cause fuel pump issues.
What causes a fuel pump to stop working?
However, this can happen due to several other reasons, such as a choked fuel filter, so you should always properly diagnose your car before replacing any parts. If the fuel pump relay may have any bad solderings inside it, it might suddenly lose the relay connection and stop delivering power to the fuel pump.
Why is the fuel pump and relay not working?
The ignition circuit, which includes the ignition switch, controls power to many components, including the fuel pump and relay. If there is an issue with the switch or the circuit, perhaps a wiring problem, then power to the fuel system may be cut off.
How to test a GMC fuel pump relay?
TEST 1: Swapping Out The Fuel Pump Relay. TEST 2: Making Sure The Fuel Pump Relay Has Power. TEST 3: Bypassing The Fuel Pump Relay. TEST 4: Bench Testing The Fuel Pump Relay. Fuel Pump Circuit Diagram. Where To Buy The Fuel Pump Relay. More GM 4.3L, 5.0L, and 5.7L Tutorials.
Is there an ECM signal to the fuel pump relay?
The fuel pump relay works as it should. I always have power to Pin 30. I believe the ECM tells the relay to work via the green/black wire to Pin 85. This should happen for 2 seconds when the key is turned on. I have tested this when the issue is occurring and have confirmed that no signal is being sent from the ECM.
The fuel pump relay does often have 4 pins, and in this case, it is often easy. If your relay has more pins and not the same numbers mentioned here, you need to check a wiring diagram. Lift it and check under it for the numbers 30, 85, 86, and 87. If you locate these numbers, you can put the fuel pump relay back.
What is the second half of a fuel pump relay?
The second half of the relay is the “switch” that controls power to a particular accessory; like a fuel pump. Terminals 86 and 85 are the primary side of the relay. It utilizes an electromagnet to close (connect) the secondary electrical circuit inside the relay.
What kind of noise does a fuel pump make?
No noise from the fuel pump. Another symptom that may hint at an issue with the fuel pump relay is no noise from the fuel pump when the key is switched on. Most fuel pumps will produce a low volume hum or whine which can be heard from the inside the vehicle if listened for closely, or from the outside of the vehicle, near the fuel tank.
How can I tell if my fuel pump relay is faulty?
2. Engine does not start. Another symptom of a faulty fuel pump relay is an engine that does not start. If the fuel pump relay fails the fuel pump will be left without power. The engine may still crank when the key is turned, however it will not be able to start due to lack of fuel.
How does a fuel pump relay control the fuel pump?
The fuel pump relay is usually controlled by the ignition or Powertrain Control Module, and when switched on, will provide current to the fuel pump so that it may function. As the fuel pump relay controls power to the fuel pump, any faults with it can cause issues with the fuel pump,…
What are the symptoms of a bad fuel pump?
The engine may still crank when the key is turned, however it will not be able to start due to lack of fuel. This symptom can also be caused by a wide variety of other issues, so having the vehicle properly diagnosed is highly recommended. 3. No noise from the fuel pump
No noise from the fuel pump. Another symptom that may hint at an issue with the fuel pump relay is no noise from the fuel pump when the key is switched on. Most fuel pumps will produce a low volume hum or whine which can be heard from the inside the vehicle if listened for closely, or from the outside of the vehicle, near the fuel tank.