If the #4 only reads a low resistance to ground, the problem is still in the PCM, but the issue may be something other than the power transistor. It turns the pump on but it is not supposed to open the injectors to spray inside the cylinder. If the resistance is still low there’s a pinched/shorted wire. Sensor Input Voltage High 24 Fuel Temp. If the #4 only reads a low resistance on the first test, unplug the PCM and retest. Make sure your fuel injector receives enough power to work properly. To circumvent it, coils should have a diode across them to short that collapsing voltage. They very likely switch ground as that’s actually easier to do, electronically. Powered by Discourse, best viewed with JavaScript enabled, Injector connector constant power, no key, short to ground. Measure resistance again. Technician B says that if the exhaust has a little oxygen the voltage of the oxygen sensor will be close to 0 volts. A short ground pulse … Testing The Fuel Injector's Wiring. mike. It sounds like the PCM has a short to ground on that driver or, inside the PCM, whatever drives that driver is active all the time. After replacing the engine-ECU, register the injector identification code and learn fuel injection (Refer to GROUP 00 - Precautions Before Service - What The Common Rail Engine Learns ). JavaScript is disabled. With the key off measure the resistance from the low side of the injector to ground. The PCM provides the ground. Note: Not all injector designs will exhibit this charac-teristic hump. P2146/008518 - Supply Voltage for Fuel Injector Group A: Open Circuit P2146/008518 - Supply Voltage for Fuel Injector Group A: Open Circuit: Open or Short to Ground Possible Symptoms. It does sound like the ECU is damaged. I suggest you set your meter for the diode test position to make the measurement. The PCM has calculated the proper injector ON time and You will need to determine where the injectors get there power supply and correct that issue. Then disconnect the computer. The engine cylinder #7 injector is operating poorly or not at all due to a problem within the circuit. @Cougar my 1994 Tercel injectors are fired in pairs. The vast majority of fuel injectors are ground controlled. If no voltage present, all wires should read high resistance to ground. Fuel injectors are used in all modern engines, and are a vital component in the fuel management system. Long story short: Providing that’s the cause of your PCM dying, I’d replace the injector as well - just to make sure. Open or short in the fuel injector harness 5. This type of injector circuit is called negative trigger. Technician A says that an oxygen sensor produces a voltage output signal based on the oxygen content of the exhaust stream. Sensor Input Voltage Low 31 Aux. As far as turning on a second injector I don’t think that is going to happen since injectors are turned on individually as far as I know. This is an open circuit test procedure using a test light and a voltmeter. 17633 - Fuel Injector for Cylinder 1 (N30) P1225 - 35-10 - Short to Ground - Intermittent 17637 - Fuel Injector for Cylinder 5 (N83) P1229 - 35-10 - Short to Ground - Intermittent 17635 - Fuel Injector for Cylinder 3 (N32) P1227 - 35-10 - Short to Ground - Intermittent 17638 - Fuel Injector for … I don’t think people will email you because we’d all be duplicating effort and it will not help people that may have this problem in the future. Getting a short to ground fault code on all 4 injectors and tank tent valve. When the computer internally grounds the injector ground wire, the injector will pulse. 23 Fuel Temp. When I probed the connecter with out the key on there is power there. Plugged fuel injector 4. If no injector pulse check fuse in engine junction box.Use a volt meter check grounds at PCM. This DTC sets when a short to ground or short to voltage condition for those cylinders is detected. No doubt your injector has that diode across it somewhere but, if that diode goes bad, you could do damage to your new PCM as well. Although generic, the specific repair steps may vary depending on make/model. Thanks @db4690 for the info about the injector pairs. what data is in the freeze frame/environmental data for the code? Thanks, Possible causes for this DTC include: 1. If this sensor short out in the WOT position you also wont get injector pulse.SO disconnect the TPS. I’d try to make sure that wire to the injector has absolutely no short to anything else. This is set by source volt-age and the resistance in the circuit. short to ground in the injector ground circuit, or defective PCM. Having found that injector #6 was spraying fuel as soon as the Key was turned on, the next step was to check to see if the injector's return circuit (Ground circuit) was shorted somewhere between the PCM and the injector connector. Observe the pattern which should be robust, if the pattern is muted the injector should be replaced. I smell fuel at the exhaust. If any of the vehicle’s fuel injectors have an issue, the air fuel ratio of the engine will be upset, which can result in performance problems. Most likely the fuel pump relay is what's causing this. Mechanic's Assistant: How many miles are on the car? Has constant voltage to injectors. Dirty Fuel Injectors - Residual fuel additive that is not dispensed within the manifold can leave a film on the fuel injectors. Loose or corroded fuel injector connector Content on vwvortex.com is generated by its users. Depending on the coil, that voltage could be several hundred volts but just a couple of microseconds in duration. With power off, unplug the harness from the injector and check the resistance of the pin on the harness (not on the injector) that the ground seeking wire is attached to and a nearby ground. This diagnostic trouble code (DTC) is a generic powertrain code, which means that it applies to OBD-II equipped vehicles. Purple Injectors GND (Ground) Low side driver control Color code for schematic lines Brown PWM Signal! Check a couple of plugs. A forum community dedicated to all Volkswagen owners and enthusiasts. If all else checks out good replace PCM. Engine Shutdown #1 or #2, Input Active 27 Air Inlet or Intake Air, Temp. Sensor Input Voltage Low 25 No Active Codes 26 Aux. Car sat for about a month because it had a power steering hose leak, I bought a new power steering hose and replaced it, and after replacement car wouldnt start, ran several test to the fuel system and found no problems with power to the fuel pump, I had bypassed the relays and directed power to the pump, the pump wasnt working, so I replaced the pump and now works properly. If there's no 12V on the other side of the injector, the ECU will report that as a "short … Injector High Side Short To GND Or VBATT Bank 1: High side short circuit to ground/positive, injector(s), injector control module: P1292: Injector High Side Short To GND Or VBATT - Bank 2: High side short circuit to ground/positive, injector(s), injector control module: P1293: High Side Open Bank No. If you get a voltage on on wire only, the the issue is still with the PCM. Could it not simply be a defective injector that either has a broken internal spring or just won’t close for some other reason? Fuel Metering Solenoid Short To Ground is the generic description for the P1281 Volkswagen code, but the manufacturer may have a different description for your model and year vehicle. This means that of the two wires going to the injector one is held at steady 12 – 14 volts while the other lead is pulsed to ground by the ECM. Injector circuit should nave hot wire anytime key is on. “Improvement in technology today will leads you a greater efficiency tomorrow” very rightly said as with the increase in dependency of human being on machines not only makes the life easy but also increases fuel demands, specifically if we talk about automobiles, the number of vehicles on road increasing tremendously since the start of the 20th century which directly reflects the fuel demands as well as prices , so it becam… So - just to clarify - that injector stops spraying when you turn the key off, sprays for four seconds when you turn the ignition on and sprays all the time (no pulses) when the engine is running? This could be due to a bad injector, an open or short connection, an intermittent open or short, a bad ground or even a bad PCM (though rare). INJECTOR RESISTANCE + WIRING TEST Faulty electrical wiring between the injectors and IDM can be an issue with the Ford 7.3L Power Stroke engine. Having power to the injector with the key off may be normal as most systems run the return side of the circuit through the ECU and no current flows in the circuit until the ECU commands the injector to turn on. 200k and it stated normally and then stopped suddenly. The ECM grounds the injectors, so it is looking for a feedback signal, and when it is not there it will set a fault code for short to ground. 1 and recheck for injector pulse Replaced fuel pump and relay, same problem. Compressed air should be released from the outlet valve with traces of fuel still remaining from the injector (use fire precautions). A P0208 code means that the PCM has stored a trouble code indicating poor performance on a fuel injector on Cylinder 8. If it’s high now the problem is in the computer (bad driver). Step 3: Touch the negative lead of the DVOM to a ground source. The car's computer turns the ground signal on and off to rapidly pulse the injector. If it is still low, then the problem is with the wire and not the PCM. It’s the job of the computer to ground each injector at the appropriate time thru the drivers in the computer. An injector is a coil, from an electrical point of view. A short to ground on the ground side will cause that particular injector to remain open and dump in gas full time causing a missfire. Attach a 12 volt power and ground source to energize the injector. Aren't injectors wired in pairs, so if it's a short to ground would it be on two injector, connectors? A shorted injector can shut down the injector drive circuit, so pull off all injector connectors, make sure fuse is good, then check for power to the injectors. Currently, we have no further information about the P1281 Volkswagen OBDII code. It may be noted that although this code … The current then con-tinues to build until the wave-form reaches its maximum cur-rent. I haven’t been getting your answers mlizotte@prodigy.net One of the most common symptoms of a potential problem with a fuel injector is engine performance issues. There should be no continuity. If you see power across the coil of that particular injector all the time, you may have a pinched wire that’s now shorted to ground, for instance. Faulty fuel injector 3. Dirty fuel injector supplying the number one cylinder 2. The hot wire should be the same color to all injectors, but the ground seeking wire should be a different color for each injector. It could be as simple as a fuse, or on some models it could be the signs of a fuel pump relay going bad. And sometimes the fuel rail assembly, which holds the injectors in place, offer little room to access the injectors without removing the complete assembly. Faulty fuel injectors affects fuel economy and can cause a misfire. the injector pintle opens and allows fuel to flow through the injector. Clogged Fuel Injectors – Many things can clog up the fuel injectors. fuel pump and fuel injectors are on a totally different circuit, it shouldn't have anything to do with your problem.... Short to ground means that either one or more of the wires is directly being shorted to ground, or the injector is internally shorted, or there could be a problem with the injector driver circuit in the pcm. Sensor Input Voltage High 28 Air Inlet or Intake Air, Temp. Car cranks but won't start? fuel pump and fuel injectors are on a totally different circuit, it shouldn't have anything to do with your problem.... Short to ground means that either one or more of the wires is directly being shorted to ground, or the injector is internally shorted, or there could be a problem with the injector driver circuit in the pcm. One side is always "hot" (from the fuel pump relay) and the ECU turns the injector ON by pulling the other side to GND. I believe that all current cars have sequential injection, though. Under what condition does it throw these codes? The car’s frame is connected to ground, so look for an unpainted piece of the frame under the hood. It may not damage them immediately, but all this zapping will age them prematurely. It can become a crusty coating on the injectors because of the heat within the engine. If +12 is missing from the high side of the injectors, the ECU will report that as a "Short to Ground" fault. A faulty fuel injector can cause the vehicle to experience misfires, a loss in power and acceleration, a reduction in fuel efficiency, and in severe cases can cause stallingor prevent the engine from runni… That spraying for four seconds is part of the system priming. A short to ground on the + side will blow fuse 31 and the engine wont run. Did you compare other injectors also to what you found on that one? I have one injector that will not stop spraying, #4. I ran about a mile with the injector runing open will I need to change the oill ? It supplies +12V to the one side of the injectors and the ECU turns the injectors ON by pulling the other side to GND. A coil that has a voltage applied to it and then when you turn it off, it fights to sustain its electric field. You can use a working injector pin for a reference to a good reading if you want to. More than likely the driver in the computer for that injector has failed. On that connection, you should see rapid pulses when the car runs and nothing when the car is not running. This residue can clog the injectors, impeding the spray. But you guys are right about the injectors. If there is a low resistance on the wire for the #4 injector only, then the driver transistor in the PCM or the wire to it has shorted out. Trouble code P0280 is a generic code (common to all manufacturers) denoting an above average current draw from the fuel injector servicing the number seven cylinder. Unlike injectors on throttle body fuel injection (TBI) systems, those used on an Electronic Fuel Injection (EFI) configuration don't have their fuel spraying accessible for inspection. If it’s really low like less than 100 ohms there’s the problem. Come join the discussion about performance, builds, modifications, classifieds, troubleshooting, maintenance, new releases, and more! Has the car been starting normally? No Start; Possible Causes. It will most likely show a low resistance when compared to the others. vwvortex.com is not in any way affiliated with Volkswagen AG. The injectors are provided with constant voltage. Supply power to injector(s) too low; Fuel Injector(s) Faulty; Wiring/connection fault; Possible Solutions. So any theoretical or concrete causes of this and why would a car run with Fuel Injector Short to ground codes? After registering the injector identification code, the vehicle equipped with the … That’s what this forum is for. That reverse voltage could potentially zap the driving electronics. The longer the ground signal is on, the more fuel is injected into the engine. Are we 100% sure its an electrical problem? VerticalScope Inc., 111 Peter, Suite 901, Toronto, Ontario, M5V 2H1, Canada, vwvortex.com is an Volkswagen enthusiast website owned and operated by VerticalScope Inc. There are ignition systems that fire two plugs at a time. Fuel Injector Driver Circuit Performance (Bank 2) Description: The PCM continuously monitors the operation of the fuel injectors and corresponding circuits for cylinders 2, 3, 5 and 8. There should only be two wires on each injector, one hot wire and one that seeks ground through the PCM. It wants to retain that charge and as the field collapses, it generates a fairly large very fast pulse of the opposite polarity (a phenomena called “Back EMF”). If you see a solid ground connection there at all times, that PCM may have an issue. If the injector really is being turned on all the time I suggest you disconnect the electrical connector to it so the injector can’t turn on and allow fuel to flow. Attach pressurized air to the injector inlet. If it is low or high on all the ground seeking wires, then test again but with power on, but before you conduct this test, do a voltage check on each ground seeking wire to make sure there is no voltage on the wire, this is to protect the meter. There could be a problem with that injector circuit inside the ECU and it is allowing current to flow. I believe my 1995 Corolla was the same way. Fuel pressure, injectors, air intake restricted / Wiring, short to ground, H025, ECM / Wiring, short to positive, short to ground, H02S, ECM P2191 System too lean at higher load, bank 1 For a better experience, please enable JavaScript in your browser before proceeding. Just some simple tools and knowledge of the circuit is needed. 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