Alan Mobile Technician North Carolina Posted Latest
2010 Honda Element EX 2.4L (K24A8) 5-spd (MNZA)
Fuel Pump Relay Found to Be Shorted Out
Ive been helping with support for this diag, so I am not at the vehicle. But so far the #2 PGM FI relay has been found to be shorted out at 1.7 Ohms on the control side. He is able to jump the relay out and get the vehicle to start and run. I had him check the current for the fuel pump while having the vehicle run and its only pulling 3.2 amps. The ECM has suffered a burned out driver for the relay, there is no control for the relay at all. I had him check the wiring to the ECM on the relays control wire, its ok, no shorts to ground or anything. But when cranking the vehicle with another relay in, the control circuit is not being pulled to ground through the ECM. The PGM FI relay #1 reads 107 Ohms on its control side coil. So Im looking for any Honda techs that may have seen this before. Is this possibly due to the pump being over worked/ overheated and taking out the relay, and then the ECM as well? He doesnt have a scope, so he cant check the pump rpm, but 3.2 amps is very low to me. I dont want to advise replacing the ECM and relay #2 without having an idea if the fuel pump caused this in the first place and that needs to be replaced as well. Vehicle has 275,000 miles on it.
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AiDN AI Assistant
California
AiDN
This is a reply from an experimental AI-powered advisor. It is important to exercise caution, verify information from multiple sources, and make informed decisions based on the prevailing circ*mstances.
Alan,It's possible that the fuel pump could have caused the issue with the relay and ECM, but it's not certain. Since the fuel pump is only drawing 3.2 amps, it's worth checking the fuel pressure and flow rate to ensure it's operating within specifications. If the fuel pump is found to be faulty, it should be replaced to avoid further damage to the new ECM and relay #2.Additionally, it's…
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Tad Owner/Technician
Florida
Tad
Hi, Alan,“Is this possibly due to the pump being over worked/ overheated and taking out the relay, and then the ECM as well?”Based on the schematic I have, the fuel pump's electrical load is not, in any way, supposed to be connected to the relay's control circuit. Therefore, a fuel pump problem might burn the relay's contacts or create a short somewhere in the harness.In theory, that kind…
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Alan Mobile Technician
North Carolina
Alan
The relay that controls the FP (PGM FI relay #2) has shorted control side coil, internal to the relay, it reads only 1.7 Ohms across the control pins of the relay. I did see that the IMMO is Fuel pump control only. My concern here is what took out the relay, its possible the relay just failed. Shorted out and took out the ECM relay driver. I also realize this diag is not ideal, but part of my…
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Tad Owner/Technician
Florida
Tad
As a general rule, PCM driver circuits are load-protected. That is, if that relay coil was shorted, the PCM should have merely released the ground for the coil and set a code for that circuit.What's the resistance through the new relay 2?The pump is not pulling enough to hurt anything, anywhere. (except, maybe, for low fuel pressure)If the wire from Relay 2 pin 3, to the PCM, was shorted…
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Alan Mobile Technician
North Carolina
Alan
Yeah I understand most ECM/PCM are protected when things like this happen, but I have also seen many drivers burn out due to shorted component coils. The resistance of PGH FI relay #1, which is the same type of relay, is 107 Ohms. Which is about 120ma of current for that type of relay. There are no shorts to ground. I had him leave the relay socket empty and unplug the ECM connector, and there…
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Tad Owner/Technician
Florida
Tad
Where are these POS relays coming from???In your OP, you stated:“So Im looking for any Honda techs that may have seen this before”While I'm not, specifically a “Honda tech”, decades of experience would have me, automatically and without further adieu, insisting on replacing BOTH the PGM FI main relays, on ANY old/high-mileage Honda with ANY sort of cranks-OK-no-start issue, regardless of…
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Alan Mobile Technician
North Carolina
Alan
Oh I fully agree, Ive already told him to get two new oem relays from a Honda dealership. Not some hondaparts.com or whatever it was, I think the low current for the fuel pump had me thinking about the pump possibly struggling. These vehicles with such high mileage always end up with more than one issue. So hes going to the dealer for some decent parts and if its still a no start…
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Tad Owner/Technician
Florida
Tad
The pump does seem to be pulling less than expected but, then, again and at the moment, low amperage generates low heat.
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Alan Mobile Technician
North Carolina
Alan
I am sure there will end up being multiple issues here. Im surprised this thing is still on the road, I dont know how I end up with all these extremely high mileage vehicles. Ive been working on a friends Pathfinder that has 260k on it, and it just keeps spitting out new codes every couple of months. Thanks for the advise though, I was heading down the rabbit hole on this one a bit.
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Timothy Owner/Technician
Wisconsin
Timothy
The pumps for these routinely pull much less than say, a Chevrolet/FCA vehicle, etc…they use a different style of pump, that pulls far less than most domestic brands.The 3.2A does not signify that it is working too hard. If it was working too hard, the amperage would be very high, not low. Low amperage is either high resistance in the ground side, bad pump (which would produce a lean…
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Glenn Owner/Technician
Texas
Glenn
Hi Alan,I think you (they) are dealing with a fuel inhibit issue, that will cause the PCM not to allow FP signal to the relay. Aside from that, the FP circuit has its own fuse to prevent issues such as overload on the PCM circuit. This is a control side issue, not a pump issue.Granted you are trying to help, but it is best to have some experienced eyes and proper test equipment on this…
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