How to test a GMC fuel pump relay?

Table of Contents

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.

Where are the fuses located in a GMC Yukon?

Cigar lighter (power outlet) fuses are located in the Engine compartment fuse box (see fuses “AUX PWR”, “CIGAR” / “CIG LTR” and “LBEC”), and since 2003 in the Passenger compartment fuse box (fuse “AUX PWR 2”). The fuse block access door is on the driver’s side edge of the instrument panel.

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.

When did the GMC Yukon XL come out?

In this article, we consider the second-generation GMC Yukon / Yukon XL, produced from 2000 to 2006. Here you will find fuse box diagrams of GMC Yukon 2000, 2001, 2002, 2003, 2004, 2005 and 2006, get information about the location of the fuse panels inside the car, and learn about the assignment of each fuse (fuse layout) and 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.

Cigar lighter (power outlet) fuses are located in the Engine compartment fuse box (see fuses “AUX PWR”, “CIGAR” / “CIG LTR” and “LBEC”), and since 2003 in the Passenger compartment fuse box (fuse “AUX PWR 2”). The fuse block access door is on the driver’s side edge of the instrument panel.

How to test the fuel pump on a Chevy Silverado?

All of the following fuel pressure test gauge kits will help test the fuel pump on your Chevrolet Silverado (Suburban, Tahoe) and GMC Sierra (Yukon, Yukon XL): As I mentioned at the beginning, testing the fuel pump simply involves connecting the fuel pressure test gauge to the fuel system.

In this article, we consider the second-generation GMC Yukon / Yukon XL, produced from 2000 to 2006. Here you will find fuse box diagrams of GMC Yukon 2000, 2001, 2002, 2003, 2004, 2005 and 2006, get information about the location of the fuse panels inside the car, and learn about the assignment of each fuse (fuse layout) and relay.

When does the fuel pump relay shut off?

Once the engine is running, the fuel pump relay shuts off. At this point, the electricity for the fuel pump is supplied by the oil pressure sending unit. When you shut off the ignition, the fuel pump relay is engaged again, long enough to power down and shut off the fuel pump.

When did I change the fuel pump on my GMC Sierra?

I changed the fuel pump on my 1996 GMC Sierra earlier in the year. I cut through my truck bed right above the fuel pump so I would have easier access to it. For the most part my truck has been fine but I have had problems with the ground wire coming from the fuel pump. At first I thought it was just the old rusty bolt that grounds the fuel pump

How to fix ground wire from fuel pump connection?

Same with the power wire from the relay to the fuel pump connector.You can also try sliding the wire between two fingers while slightly bending the wire to feel for a soft spot but this may not work due to the fact that it works sometimes so the bad spot isn’t real big yet. 5 people found this helpful.

What kind of fuel pump does a Chevy truck use?

Fits perfectly for any 1988 to 1998 fuel pump in a Chevy truck. Fuel pump is great and I haven’t had any problems with it. Also the warranty is good to have, always. Pages with related products. See and discover other items: 94 silverado, 95 gmc sierra, 1989 gmc sierra, pump fuel, parts for chevy 1989, 1992 gmc parts

Once the engine is running, the fuel pump relay shuts off. At this point, the electricity for the fuel pump is supplied by the oil pressure sending unit. When you shut off the ignition, the fuel pump relay is engaged again, long enough to power down and shut off the fuel pump.

I changed the fuel pump on my 1996 GMC Sierra earlier in the year. I cut through my truck bed right above the fuel pump so I would have easier access to it. For the most part my truck has been fine but I have had problems with the ground wire coming from the fuel pump. At first I thought it was just the old rusty bolt that grounds the fuel pump

How to test a GM 4.3L fuel pump?

More GM 4.3L, 5.0L, and 5.7L Tutorials. It’s very important that you start off your fuel pump relay diagnostic by first testing the fuel pump pressure with a fuel pressure test gauge. If the fuel pump relay IS NOT activating the fuel pump, the fuel pressure test gauge will register 0 PSI when cranking the engine.

When to know if your GMC Sierra fuel pump is bad?

If your car isn’t starting at all, and you hear the fuel pump prime that is usually a good indication that the pump is working to some capacity. Testing your Sierra’s fuel pressure on each side of the pump would be the best way to diagnose this problem.

What should fuel pressure be if fuel pump is not activating?

If the fuel pump relay IS NOT activating the fuel pump, the fuel pressure test gauge will register 0 PSI when cranking the engine. If the fuel pump relay is activating the fuel pump, then it’ll register about 56-62 PSI even if the engine does not start. Any fuel pressure below 50 PSI and the engine will NOT start.

Why does my GMC Sierra have a bad fuel pump?

If you get P0420 or P0430 trouble codes with a scanner, it very well may be the catalytic converter causing these symptoms. One of the best indicators of a clogged fuel pump is going to be that the your Sierra is difficult to start. This because there’s not enough fuel pressure to properly atomize the fuel as it enters the combustion chamber.

What are the symptoms of a bad fuel pump?

Also, the symptoms are almost exactly the same as bad/clogged fuel filter. Here are the most common symptoms of a bad fuel pump in your GMC Sierra: One of the most common signs that a fuel pump is going bad is a whining sound. The whining sound can indicate that the fuel pump is going out before there are any performance based issues.

Where is the gas gauge located on a Chevy truck?

The gas gauge, often located in the instrument cluster, consists of two small coils spaced 90 degrees apart with an armature and a needle placed at the intersection of the two coils. A dampener is also located on the armature to prevent excessive needle movement on rough roads.

Where does the fuel pump go in a car?

In modern fuel injected vehicles, the fuel pump sits right in the fuel tank and “pushes” the gasoline to the fuel rail (s). It is in the fuel tank because “pushing” fuel to the fuel rail is easier than “pulling” the fuel, which is what an inline pump would do.

How to check fuel pump signal in gmflash?

1. CONNECT PIN1 (BLACK GROUND) TO PIN16 (PINK GROUND) 2. CONNECT PIN32 (RD/WH BATT + ) TO PIN47 (GY FUEL PUMP 12+) THIS WILL POWER THE PUMP TO RUN AND CHECK FOR A FAULTY FUEL PUMP. 3. NEXT, CHECK FOR FUEL PUMP SIGNAL AT THE FUEL SYSTEM CONTROL MODULE. 4. FIND THE DARK GREEN/WHITE WIRE IN PIN13.

How to test and replace a fuel pump relay?

How to test and replace a fuel pump relay. The principles shown here apply to most vehicles. However, it’s best to check with your vehicle’s repair manual for testing parameters.This specific vehicle is a ’97 Nissan Maxima. — Choosing the best oil filter: Wix XP / Amsoil / Royal Purple..

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.

Where is the fuel pump control module located?

It is often found in the fuse box located in the engine bay and functions as the primary electronic switch that controls power to 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.

What should I do if my fuel pump is not working?

Use Jumper wires to supply 12v power to terminals 86 and 85. Next, use a test light on terminals 87 and 30, to see if you have power. Finally, if the test light goes on the the problem lies somewhere else. Fuel Pump Circuit Breaker Reset

What are the symptoms of a bad fuel pump relay?

As the fuel pump relay controls power to the fuel pump, any faults with it can cause issues with the fuel pump, which can cause drivability problems for the vehicle. Usually a bad or failing fuel pump relay will produce a few symptoms that can alert the driver of the issues. 1. Engine stalls

What are the symptoms of a faulty fuel pump relay?

1 Engine does not start. A common symptom of a faulty fuel pump relay is an engine that just refuses to start, even though the engine may still crank when the 2 Engine stalls. One of the most common symptoms of a failing fuel pump relay is an engine that suddenly stalls. 3 Loss of Power. 4 No noise from the fuel pump.

Where is the fuel pump relay located on a car?

The fuel pump relay is an electronic component that is found on virtually all vehicles equipped with an internal combustion engine. It is often found in the fuse box located in the engine bay and functions as the primary electronic switch that controls power to the fuel pump.

If the fuel pump relay IS NOT activating the fuel pump, the fuel pressure test gauge will register 0 PSI when cranking the engine. If the fuel pump relay is activating the fuel pump, then it’ll register about 56-62 PSI even if the engine does not start. Any fuel pressure below 50 PSI and the engine will NOT start.

How to test the crank sensor on a GM 4.3L engine?

Unplugging this connector will disable the computer from injecting fuel into the engine. You don’t need any expensive tools to test the crank sensor on your 4.3L, 5.0L, 5.7L engine. Multimeter. You can use a digital multimeter or an analog multimeter although the digital one is the preferred one.

What does the crankshaft position sensor ( CKP ) do?

So, The crankshaft position sensor (CKP) monitors as a multi functional sensor used to set ignition timing, detect engine (RPM) and relative engine speed. This sensor voids the need for manual distributor timing. Because, The sensor (CKP) is used to determine which cylinder is firing to synchronize the fuel injector and coil firing sequence.

What happens when a fuel pump relay goes bad?

If the fuel pump relay has an issue while the vehicle is operating it will cut off power to the fuel pump, which will cause the engine to stall. A faulty relay may allow the vehicle to be restarted a short while later, while a completely failed relay will not.

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,…

Unplugging this connector will disable the computer from injecting fuel into the engine. You don’t need any expensive tools to test the crank sensor on your 4.3L, 5.0L, 5.7L engine. Multimeter. You can use a digital multimeter or an analog multimeter although the digital one is the preferred one.

Where is the voltage on the fuel pump?

It is located at the back of the vehicle next to or in the fuel tank. It pumps fuel from the tank to the engine. The pump voltage test is important for checking the effectiveness of the fuel pump.

What happens if your fuel pump is failing?

The fuel pump feeds fuel to the engine at a reliable rate; without this pump, your fuel would just sit in your tank, useless and inert. If you’re attentive, you can catch the symptoms of a failing fuel pump and have it repaired or replaced before it leaves you stranded on the side of the road.

What should the voltage be at the fuel pump relay?

You should have 12 volts at the dark green/yellow wire at the fuel pump relay. The inertial fuel shutoff switch is between the relay and the fuel pump. The pink/black wire from the inertial switch to the fuel pump should have 12 volts. You can measure the voltage, on the pink/black wire, at the fuel pump.

How does voltage and current affect fuel pump?

Fuel pressure and volume are influenced by voltage, current and the demand controlled by the regulator. If a fuel pump is not receiving the correct voltage, it cannot spin fast enough. Voltage drop testing can isolate problems that can still remain even if the pump is replaced.

What causes a fuel pump to malfunction?

Electronic pumps are typically linked to electronic control systems and contain multiple moving parts; because of this increased complexity, these types of pumps are more prone to failure. Any one of several different parts can malfunction and lead to fuel pump problems.

How does a GMC Sierra 1500 fuel pump work?

The older model has steel lines coming off of the top of the pump to the frame rail and then connects to the frame steel lines with short hoses, you’ll need line wrenches and the ability to curse. The newer style has plastic tubes from the plastic pump casing and uses those quick connect fuel fittings and you’ll need the disconnect tool.

More GM 4.3L, 5.0L, and 5.7L Tutorials. It’s very important that you start off your fuel pump relay diagnostic by first testing the fuel pump pressure with a fuel pressure test gauge. If the fuel pump relay IS NOT activating the fuel pump, the fuel pressure test gauge will register 0 PSI when cranking the engine.

How to check for a faulty fuel pump?

THIS WILL POWER THE PUMP TO RUN AND CHECK FOR A FAULTY FUEL PUMP. 3. NEXT, CHECK FOR FUEL PUMP SIGNAL AT THE FUEL SYSTEM CONTROL MODULE. 4. FIND THE DARK GREEN/WHITE WIRE IN PIN13. WITH A TEST LIGHT CONNECTED TO THAT WIRE, TURN THE KEY TO THE RUN POSITION.

How to install new GM wire harness on fuel pump module?

If playback doesn’t begin shortly, try restarting your device. Videos you watch may be added to the TV’s watch history and influence TV recommendations. To avoid this, cancel and sign in to YouTube on your computer. An error occurred. Please try again later. (Playback ID: WfYJuntPOgNiQAf9)

1. CONNECT PIN1 (BLACK GROUND) TO PIN16 (PINK GROUND) 2. CONNECT PIN32 (RD/WH BATT + ) TO PIN47 (GY FUEL PUMP 12+) THIS WILL POWER THE PUMP TO RUN AND CHECK FOR A FAULTY FUEL PUMP. 3. NEXT, CHECK FOR FUEL PUMP SIGNAL AT THE FUEL SYSTEM CONTROL MODULE. 4. FIND THE DARK GREEN/WHITE WIRE IN PIN13.

THIS WILL POWER THE PUMP TO RUN AND CHECK FOR A FAULTY FUEL PUMP. 3. NEXT, CHECK FOR FUEL PUMP SIGNAL AT THE FUEL SYSTEM CONTROL MODULE. 4. FIND THE DARK GREEN/WHITE WIRE IN PIN13. WITH A TEST LIGHT CONNECTED TO THAT WIRE, TURN THE KEY TO THE RUN POSITION.

Which is the secondary side of the fuel pump relay?

Terminals 87 and 30 are the secondary side of the relay. Consequently, It acts as the “switch” that connects electrical current, from one terminal to the other. Use Jumper wires to supply 12v power to terminals 86 and 85. Next, use a test light on terminals 87 and 30, to see if you have power.

What is the wiring diagram for a fuel pump?

Backfiring Distributor Wiring Diagram l 2wd C Asked by Pelacaman · Chevy Silverado Fuel Pump Wire. Electrical Problem. Relay. , , Chevy/GMC Pick Up, Suburban, Tahoe, Yukon. How To Test The Fuel Pump Relay ( Chevy/GMC Pick Up) Fuel Pump Circuit Diagram.

Where can I test my fuel pump relay?

Where To Buy The 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.

Where is the fuel engine control relay located?

Sometimes the ECU is suspect and other times it is this relay. It is located behind the carpet panel on the passenger side of the center console.