2013 dies repeatedly while driving down the road

[CharlieS]

Okay, so I did what I suggested in the post above. Easy enough since everything is open now.

What I found was that when the engine stalled, the power to the pump goes down to a negligible amount.

When the ignition is off, it has 0 mV
Once started, it runs up to 10.30 V
it does that constantly (well, 10.30 then 10.31 and back and forth)
Then it drops down to 8.33 V and then within seconds loses power (no voltage) , and after a few seconds cycles dow to about 7.8 mV.

Edit, please note the millivolts when it dies, versus volts when it is running.

Thoughts?

 

[RET2]

Relay somewhere is shorting out then resets it's self, question is which one?

 

[CharlieS]

These may be worth looking through. Start with the "fuel pump overview."

These are awesome! Thanks! Do you know where the N3 connector is (to the fuel pump ECU)? Is N3 a reference on a grid overlaying the body locations?

Looks like possibly by the rear passenger side wheel well, maybe?

 

[OEMGUY0720]

OEMGuy, any chance you have the part number you used for your Denso pump?
Did you do the work yourself? If so, what plastic air ducting did you have to remove to get to the pump access hatch? That must've been a miserable job in that heat!

The 100 and 200 series’ fuel pump are on the same area, driver side 2nd row seats (saw your recent posts that you accessed it already). I did the swap myself here in my garage. With the help of a fellow mudder I got the part # from him. This is what solved my heat soak stalling problems:

Side by side comparison of my faulty fuel pump:

What I discovered was that the 06 and 07 LC/LX (VVTi) has a different fuel pump from the previous models (non-VVTi) mine was 2-speed type.

 

[CharlieS]

This was on a 100 series, yes? I wonder if it fits the 200. Denso doesn't show any cross referenced pumps or filters (but I am sure they make them...).

 

[bloc]

I’m pretty sure feeding the pump 12v won’t hurt it at all, likely just produce more fuel flow than the truck expects at idle, possibly raising fuel pressure and maybe even making it run rich. The STFTs should address this. You could temporarily give the pump fused +12v directly and see if the stalling issue goes away to see if it’s a pump or a control problem.

I think the timing of the voltage drop you see is critical.. if it’s just shutting down power to the pump because it sees the engine die for some other reason that could be interpreted as voltage drop shutting down the pump first.

I’ll do some digging when I get home for the fuel pump ECU location.

 

[indycole]

These are awesome! Thanks! Do you know where the N3 connector is (to the fuel pump ECU)? Is N3 a reference on a grid overlaying the body locations?

Looks like possibly by the rear passenger side wheel well, maybe?

Soooo... I actually wonder if N3 is a typo and the actual component is N13. I'm not seeing an N3 anywhere in the component list in the FSM. It actually jumps from N2 to N4. However, I do see an N13 as part of the fuel system and the document references it.

Assuming it's N13 see the attachments.

 

[CharlieS]

Super interesting, I got N3 from the 2013 EWD and the 2013 version of that connector position diagram. It is just very confusing where it actually is based on the connector diagram. I couldn't see it anywhere on the inside of the vehicle, even with everything removed from the second row area. Since it is on the frame, that makes a ton more sense.

I just did a quick visual inspection and it is right where you say. It is on top of the passenger side frame rail, bolted to the frame on a bracket, beneath the body. It is visible from the outboard side of the frame (I was laying on a blanket on the ground). It's a pretty snug spot, so getting it out will be fun .

I can see the wires pretty well though, and they include the black with white tracer (FP+ on terminal 1) and white with black tracer (FP- on terminal 2) that go to the fuel pump; plus black (+ from the battery via EFI NO 2 Relay), white (ECM "FPC" control signal on terminal 5), and white with black tracer (body ground on terminal 6).

The (white) signal wire comes off pin 52 on the ECM.

Also, a correction to my earlier post - the power that energizes EFI NO 2 relay comes from the A/F relay. I better make sure I test that one if I haven't already.

Bingo!

So if I test the voltage with a back probe on the white wire, I can see if the main ECU is giving a signal when the engine dies? I can do the same with the power signal coming in on the black wire to ensure it isn't cutting power from that side of the circuit? Divide and conquer!

Thanks!

 

[CharlieS]

I’m pretty sure feeding the pump 12v won’t hurt it at all, likely just produce more fuel flow than the truck expects at idle, possibly raising fuel pressure and maybe even making it run rich. The STFTs should address this. You could temporarily give the pump fused +12v directly and see if the stalling issue goes away to see if it’s a pump or a control problem.

I think the timing of the voltage drop you see is critical.. if it’s just shutting down power to the pump because it sees the engine die for some other reason that could be interpreted as voltage drop shutting down the pump first.

I’ll do some digging when I get home for the fuel pump ECU location.

So even though it was running at 10.30 volts input voltage, you think it would be safe to give it battery voltage (13V while idle and 14.5+ V when running)? That makes me nervous. I wish I knew more about resistors so I could step the voltage down. Or more about the range of acceptable voltage to the pump...

 

[OEMGUY0720]

This was on a 100 series, yes? I wonder if it fits the 200. Denso doesn't show any cross referenced pumps or filters (but I am sure they make them...).

Yes this was on my 2006 LX470. The fuel pump part number I used came off originally from a Toyota Sequoia. I’m sure by digging in more you will find a Denso replacement as the OEM will surely cost more (even though it’s also made by Denso - they just have different part #s).

Have you tried using partsouq.com to search for you oem fuel pump part number? That’s the best place to start.

 

[CharlieS]

I haven't, but I will now. Thanks.

 

[Romer]

Something is telling circuitry to cut the voltage based on your readings. Not sure why the fuel pump part number matters anymore

We need to figure out the logic that can disable this circuitry to remove the voltage. Did you say it was a slow deceleration or just a complete shut off?

I have an electronic FSM I will look at when I get home, but I think Cole has posted parts of it already

 

[indycole]

I'd consider Romer's logic here. Personally, I don't know if it's worth extracting the fuel pump until there's more evidence of the pump being the problem or just a symptom. The lack of a CEL or DTC P0230 (as per FSM) makes me think your problem is upstream, electronically. The FSM states that the fuel pump speed is determined by engine output which the ECM converts into a waveform for the fuel pump ECU (hence what you mentioned about 3 speed settings). Why does the ECM think the engine doesn't need fuel?

It's hard because I haven't really followed everything that you've done (my initial reaction was that it's time to take it to the dealer, but I can appreciate having a fun technical problem to solve when you have the skills).

Were you able to rule out sensors/shorts/electrical gremlins that would make the ECM believe there's something wrong with the input or output of the engine?

 

[bloc]

OE pump number: 23220-50271

Fuel pump ECU PN: 89571-60030 (about $200 on a discount site if you end up needing one. Bit too expensive to just throw one at it. Know someone you can borrow off of?)

So even though it was running at 10.30 volts input voltage, you think it would be safe to give it battery voltage (13V while idle and 14.5+ V when running)? That makes me nervous. I wish I knew more about resistors so I could step the voltage down. Or more about the range of acceptable voltage to the pump...

Toyota suggests hooking up battery voltage to test the pump, but it wouldn't be while running. I guess if you are worried about more than 12v you could supply it with an external battery separate from the vehicle. Note that toyota says if the pump is smoked you need to replace the Fuel Pump ECU too.

Not sure what coil they are referring to.. within the pump? Actually kinda makes it look bad for just giving it external voltage to run on. Might want to dig up those resistor values.

Also note that my version of TIS for a 2013 shows a very slightly different bracket holding on the Fuel Pump ECU.

Were you able to rule out sensors/shorts/electrical gremlins that would make the ECM believe there's something wrong with the input or output of the engine?

The lack of relevant DTCs makes me think the engine likes what it sees in terms of inputs.

Supplying the pump externally can confirm the ECU or an external factor is killing voltage to the pump. Based on the description and the lag inherent in many voltmeters I'm not ready to assume the ECU is cutting voltage yet. But that's just me.

 

[CharlieS]

Something is telling circuitry to cut the voltage based on your readings. Not sure why the fuel pump part number matters anymore

We need to figure out the logic that can disable this circuitry to remove the voltage. Did you say it was a slow deceleration or just a complete shut off?

I have an electronic FSM I will look at when I get home, but I think Cole has posted parts of it already

I agree with you completely.

It is a slow deceleration (corresponds to when the pump input drops from 10v to 8v) and then dies (when it loses power, then reads milivolts).

The part number of the Denso pump would be useful for two reasons: so 200 series mudders can have a good lower cost option, and also since I am in this far, I may do a preventative maintenance on the pump. Disassembling the second row area was a hassle... and I have the lock ring tool on its way... might as well refresh that part for another 100k trouble free miles.

Unfortunately, no local 200 DIY people. I only ever see one other 200 driven by a soccer parent a few towns over. A few 100 and 80 series in the area. If I see about one other cruiser a month.

At this point, I have observed that voltage to the pump is being removed. Logically it must be by some control unit. determining whether that voltage loss is resulting from a failed Fuel Pump ECU, or from the main ECM removing the trigger signal is my next task. I have a plan for troubleshooting the Fuel Pump ECU.

If it is upstream, toward main the ECM, then it'll lead me down a different troubleshooting path - as in what input to the ECM, or failure in the ECM is causing the loss of signal To the fuel pump ECU.

Oceans razor suggests it is the Fuel Pump ECU, but I'm not ready to test that with a $200 part.

Right now, I'm taking a bourbon break. My head hurts.

 

[CharlieS]

OE pump number: 23220-50271

Fuel pump ECU PN: 89571-60030 (about $200 on a discount site if you end up needing one. Bit too expensive to just throw one at it. Know someone you can borrow off of?)





Toyota suggests hooking up battery voltage to test the pump, but it wouldn't be while running. I guess if you are worried about more than 12v you could supply it with an external battery separate from the vehicle. Note that toyota says if the pump is smoked you need to replace the Fuel Pump ECU too.


View attachment 2068352


Not sure what coil they are referring to.. within the pump? Actually kinda makes it look bad for just giving it external voltage to run on. Might want to dig up those resistor values.

Also note that my version of TIS for a 2013 shows a very slightly different bracket holding on the Fuel Pump ECU.

View attachment 2068342



The lack of relevant DTCs makes me think the engine likes what it sees in terms of inputs.

Supplying the pump externally can confirm the ECU or an external factor is killing voltage to the pump. Based on the description and the lag inherent in many voltmeters I'm not ready to assume the ECU is cutting voltage yet. But that's just me.

View attachment 2068342

View attachment 2068352

I just applied 12v power directly to the fuel pump leads and it ran without issue.

Resistance through the fuel pump is 0.7 ohms.

Bloc - the bracket looks like the one you posted. Two philips screws attaching the sensor to the bracket and the bracket bolted to the top of the frame rail.

 

[silverhorse]

great info in this thread!

 

[CharlieS]

I'd consider Romer's logic here. Personally, I don't know if it's worth extracting the fuel pump until there's more evidence of the pump being the problem or just a symptom. The lack of a CEL or DTC P0230 (as per FSM) makes me think your problem is upstream, electronically. The FSM states that the fuel pump speed is determined by engine output which the ECM converts into a waveform for the fuel pump ECU (hence what you mentioned about 3 speed settings). Why does the ECM think the engine doesn't need fuel?

It's hard because I haven't really followed everything that you've done (my initial reaction was that it's time to take it to the dealer, but I can appreciate having a fun technical problem to solve when you have the skills).

Were you able to rule out sensors/shorts/electrical gremlins that would make the ECM believe there's something wrong with the input or output of the engine?

Lots of stuff here.

First, I agree with your line of reasoning.

If I replace the fuel pump, it would be after I figure out the root cause of the issue, and fix it.

My troubleshooting so far suggests that the pump stopping is a symptom, not the root cause.

Replacement of the pump would be primarily for preventative maintenance reasons. Sometimes the time and effort to get to a component makes me opt to replace it as a future time saver. Like when you replace a clutch that still has some life when you have the transmission dropped for another reason. I think of these as "while you are in there" jobs.

I believe I have ruled out electrical shorts, grounding, water intrusion, fuses, sensors and relays. Some of those are from visual inspection, others are from component bench testing, others are inferred from lack of codes in OBD/Techstream.

I think the ECM is happy with it's inputs. The risk is that I am missing something, because I don't know what to look for, or I am making bad assumptions.

The fuel pump is testing out good, at least from the tests I have tried from the fsm.

I'm leaning toward electronic control unit failure or erroneous ECU/ECM inputs. I don't like to guess though, so I'm trying to systematically troubleshoot and isolate until I get to a root cause.

Worst case, I put it back together and take it to the dealer. I'd rather not, since I feel like I should be able to figure it out with 'mud help.

I just have to wonder what the UN, an Australian mine operator, other severe service operator would do if stuck with a failure like this. It doesn't feel very Land Cruiser like. We should be able to fix these rigs with bailing twine and barbed wire!!

 

[chilibit]

Do you think the modulation of the fuel pump speed is governed by the pump ecu? Based possibly on an air/fuel mix value from the engine ecu. That was a question, I am just looking for a culprit that could do what you witness.

 

[indycole]

I just have to wonder what the UN, an Australian mine operator, other severe service operator would do if stuck with a failure like this. It doesn't feel very Land Cruiser like. We should be able to fix these rigs with bailing twine and barbed wire!!

Yeah, what you're seeing is definitely one of the most obscure issues I've heard of with these trucks. I hear you with the "while I'm in there" argument for replacing the fuel pump but from a debugging perspective you're introducing new variables into the equation. Not saying I wouldn't consider the same thing, just that my personal preference while debugging is to eliminate variables, not increase them. Since you tested the pump and verified it's working I'd leave it alone from there. Instead, before you close up shop, go back and replace the fuel pump once you sort out and address the root cause. That takes advantage of the knowledge and experience while minimizing rework. Probably not a huge deal, though, either way. I guess I've just been burnt by buying new parts that turn out to be defective too many times.

It sounds like at this point you're down to the ECM, the fuel pump ECU, and the harnesses related to those?