isuzu npr glow plug controller location
Welcome to solsarin, Have you ever thought about this question “isuzu npr glow plug controller location” Today on Solsarin we’re going to answer this question.
What is a glow plug control module?
As you already know, a glow plug is a heating device in each cylinder of a diesel engine that helps the engine to start. But how is the overall operation of your glow plugs monitored and controlled? This is done by a glow plug control module.
Located on the engine and with a direct connection to the engine control unit, the control module uses a microprocessor to analyze input from the engine control unit to determine information related to the working of the glow plugs. This includes when to switch the current for the glow plugs on and off, and how much current is required as this will differ depending on the starting temperature of the engine. The current to the glow plugs is turned on during the pre-heating to warm up the engine, stand-by time when the engine should be started, and post-heating to meet increasingly strict exhaust gas standards and optimization of combustion processes.
When you start up a diesel-powered vehicle, the following actions happen:
- The glow plug control module determines the timing and electric current required by the glow plugs based on input from the Engine Control Unit;
- The heating element in the glow plug is electrified so it heats up and emits visible light (hence the name);
- Intake air is compressed;
- The fuel injector spray directs fuel onto the hot tip of the glow plug;
- The injected fuel mixes with the compressed air evaporate and starts combustion almost simultaneously, even when the engine is cold;
- The glow plug remains on during the pre-heating phase to ensure correct combustion of the fuel and reduce the environmental impact of your car.
This process is helped by the increase in temperature of the intake air during compression and the relatively low ignition temperature of diesel. However, a glow plug control module is still essential, as without it controlling your glow plugs, the compression temperature might not be high enough to ensure proper ignition of the injected fuel in a cold diesel engine. This would result in increased exhaust emissions.
What are the symptoms of a defective glow plug control module?
A diesel engine has one glow plug control module which controls the glow plugs. This means that you might not notice when a single glow plug goes bad as this only affects one cylinder in your engine. However, if two of three go bad or the control module itself malfunctions, you’ll quickly find it difficult to start the engine. In addition to watching out for the glow plug light on your dashboard, here are some common symptoms of a defective glow plug or glow plug control module:
- White exhaust smoke – a defective glow plug will cause diesel to leak into the exhaust where it burns.
- Hard to start – this could mean the engine is slow to start in warm weather or fails to start in cold weather. However, this can also be a symptom of a problem in the fuel system or battery.
- Poor engine power – after a difficult start, bad glow plugs will make it difficult for your car to run properly, due to improper combustion which reduces power and efficiency.
How can you test your glow plug control module?
First things first, is it a problem with your glow plugs or your glow plug control module?
The easiest is to check your glow plugs before testing your glow plug control module.
To test your glow plugs, simply connect a 12-volt test light to the positive battery terminal. Then disconnect the wires from each of your glow plugs and touch the probe of the test light to the terminal of the glow plug itself (not the wiring harness). If the light doesn’t light up, the glow plug is bad and should be replaced.
Easier is to use a professional glow plug tester device.
There is some discussion about whether you should only replace the glow plugs that have gone bad, or if it is best to replace them all. As one glow plug going bad could be a sign that the others will shortly follow, some experts recommend replacing them all at the same time while others suggest keeping a close eye on the remaining glow plugs.
If your glow plugs are all working correctly, move onto your glow plug control module. Start by checking the battery voltage to the glow plug control module, a voltage drop of over a half volt (or more) means your control module should be replaced.
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How to choose the right glow plug control module?
As glow plugs and glow plugs, control modules don’t come in a one-size-fits-all format, it is important to select the correct type for your car and the type of fuel that you use. Additionally, using premium components is recommended, as a low-quality part can cause expensive consequences for your engine. For example, a swollen glow plug constructed from sub-par materials would either be impossible to remove later or the tip would break off in the cylinder, causing damage to the cylinder, valve and head.
When should you replace your glow plug control module?
Replacing your glow plugs or glow plug control module is a straightforward project that is recommended every 60,000 miles (95,000 km). This will help ensure that you don’t find out they’ve gone bad on a really cold day.
Before you start, ensure that you have read all relevant instructions in your owners’ manual and have all relevant tools at hand.
Champion glow plug control modules
Champion offers a range of quality glow plugs and glow plug control modules suitable for all types of diesel engines. Discover the full range for yourself.
Glow plug control
When the relay clicks on and then off right away and you can see it in the dome light (and you know the plugs are good) I think the glow plug’s current is probably normal but the current sense circuit is not. This is made up of the short bus strip that feeds the main glow bus bar and it has a small wire connection at each end. These two wires run back to the glow controller to inform it of the glow current. If the wires are broken (or other fault) the controller will shut the glow interval down very early.
This is because the controller looks for a decline in current below about 40 amps to decide when to turn off the glow. The plugs have a positive temperature coefficient so the resistance goes up as they heat and the current declines. Also, if one glow plug is out the current will be too low and the controller will shut down early.
It is also still possible that there is a problem in the heavy wiring that feeds the current to the glow bus which would cause the current to be low and thus fool the controller into shutting down early.
This is less likely with your symptoms but it may be that the engine temperature sensor for the glowing controller is at fault. This is the unit on the top of the thermostat housing with one yellow wire coming from it.
You can easily test for this by pulling apart the bullet connector in the yellow wire which will tell the glowing controller that the engine is cold and it should glow. If this works, you don’t want to leave this disconnected as the glow plugs will then operate every time you start the engine even if it is hot. This would likely shorten the life of your plugs.
The glow controller circuit is grounded by a wire from the harness and there is no connection via the mounting ears so that should not be a problem.
How to Repair ISUZU N-Series Truck U0106 GPCM Communication Lost
Some customers may complain of an illuminated Check Engine Malfunction Indicator Light (MIL) associated with Diagnostic Trouble Code (DTC) U0106, Lost Communication with Glow Plug Control Module (GPCM). This condition may be the result of water intrusion into the GPCM connector. Water from rain and other outside sources can pool in the glow plug recessed area on the outside of the cylinder head. If enough water accumulates, it can seep into the glow plug harness through the terminal ends and enter the GPCM connector, causing this DTC to set.
If this DTC is found and evidence of water is present in the GPCM connector, replace the glow plug harness terminals as outlined in the service procedure in this bulletin. The replacement terminal ends are sealed so that water cannot get into and through the wire.
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