2013 dies repeatedly while driving down the road (1 Viewer)

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Seems fuel related to me.
Have a read from the link below. At least you will be able to tell if its the ecu, ecm or fuel pump.


Best of luck,
David
 
There are also branches where it says "normal" and "abnormal". As in the question "Was the air-fuel ratio abnormal or normal?". Does anyone know how Toyota means this? Is that short term fuel trims (SHRTFT1/SHRFT2)\ in a particular range? Or is there some other observable value that I can watch (and what is the "normal" value)?

Normal. Yes, concluding that from the ST/LT trims and also your observations of the engine running smoothly at different RPMs prior to stall. Abnormal would show a notably rough running engine prior to stall.

The first question is "While idling or while driving" so maybe it doesn't matter. It happens both while idling and driving. Driving only has 3 options: "sensor malfunction", "injection and ignition stoppage" and "fuel supply problem". So let's say it needs to be one of those three.

You've explored open loop operation which depends much less on sensors. The critical sensors are crank angle and cam angle at that point. To really rule out sensors, you could disconnect MAF, coolant temp, O2, knock. Yet we're not getting CELs in any of these.


Now looking at the "while idling" branch, I need to decide if it decreased slowly or decreased rapidly when stalling. Lets say I say it decreased rapidly (2-3 seconds is pretty rapid, I guess), it narrows it to two options: "injection and ignition stoppage" and "load from external parts". The commonality in these two branches of the tree is "injection and ignition stoppage".

If both of my answers were correct, than the only commonality between the idling and driving branches is "injection and ignition stoppage".

I agree it's hard to interpret slowly or rapidly. Either way, it's not "load from external parts". It is an injection (fueling) or ignition (spark) stoppage issue.

This leads me to the next table, which says the suspected area is "power temporarily cut". It says the primary parts to inspect are the Power supply circuit (fuel injector, ignition coil assembly), and points me to procedure 62 and 63.

I would explore this area as it's my suspicion based on your symptoms.
 
I was poking around in the engine bay tonight - I disconnected some stuff to see what would happen...

Something that surprised me was that the engine stalled almost immediately when I unplugged the MAF sensor while it was running. I tried this a half dozen times and every time it stalled the engine.

Could this be my bad sensor, even though it isn't throwing a code?

Is that the behavior I should expect?
 
Could this be my bad sensor, even though it isn't throwing a code?

Is that the behavior I should expect?

I recently had a minor MAF sensor issue (it was dirty) and I would get a CEL almost immediately after starting up. I'm still super curious about why you're not getting a CEL for any of these issues, but I'm not sure of any standalone issue that would cause a missing CEL other than internal ECU/ECM issues or ECU/ECM power? It'd really be handy to have another 200 at your disposal.
 
I was poking around in the engine bay tonight - I disconnected some stuff to see what would happen...

Something that surprised me was that the engine stalled almost immediately when I unplugged the MAF sensor while it was running. I tried this a half dozen times and every time it stalled the engine.

Could this be my bad sensor, even though it isn't throwing a code?

Is that the behavior I should expect?

I used to have a Porsche 911tt. A few guys would have faulty MAF sensors, and the car would behave similar to what you described, car shuts down suddenly. But I believe they do get CEL.
 
I've unplugged the MAF on both of my 911s and they keep running. Wierd.
 
I recently had a minor MAF sensor issue (it was dirty) and I would get a CEL almost immediately after starting up. I'm still super curious about why you're not getting a CEL for any of these issues, but I'm not sure of any standalone issue that would cause a missing CEL other than internal ECU/ECM issues or ECU/ECM power? It'd really be handy to have another 200 at your disposal.
Definitely. Maybe I should suggest to my wife that I get a spare 200 series. :)
 
You have two 911s?!?
Yes, but it isn't as cool as it sounds. They're the 996 generation, the first water cooled 911, and they sell cheaper than a used civic. The Porsche faithful don't believe in anything but proper air cooled engines. And the M96 in these cars has a bearing that likes to blow up and take out the whole engine, so it gets beat up in the used car market. I really only intended to have one, but the second one came along as a deal I couldn't refuse - I haven't sold the other yet, although it is for sale.
 
Yes, but it isn't as cool as it sounds. They're the 996 generation, the first water cooled 911, and they sell cheaper than a used civic. The Porsche faithful don't believe in anything but proper air cooled engines. And the M96 in these cars has a bearing that likes to blow up and take out the whole engine, so it gets beat up in the used car market. I really only intended to have one, but the second one came along as a deal I couldn't refuse - I haven't sold the other yet, although it is for sale.

I had a 996tt. I believe the 996 is a good buy, and actually drives "better" than the 997/991, more analog feel of the road, and like you said, a relative bargain to buy. Expensive to maintain though....

Sorry to derail your thread on P cars.

Back on topic, is it possible to clean the MAF sensor on the LC?
 
I had a 996tt. I believe the 996 is a good buy, and actually drives "better" than the 997/991, more analog feel of the road, and like you said, a relative bargain to buy. Expensive to maintain though....

Sorry to derail your thread on P cars.

Back on topic, is it possible to clean the MAF sensor on the LC?
Agree on all counts. The turbos are amazing - twice as nice a car compared to the base carerra. I could sell both of my carerras and not make enough to buy a 996TT. Those Mezger engines in the turbo, GT2 and GT3 don't have the same issues as the M96. I lust after a GT3... And yes, they are a lot of either money or work to maintain, but I love working on cars, so it is okay for me. The only thing I've paid to have done are tire changes and alignments. I've done everything else myself.

Yes, a MAF can be cleaned. I actually cleaned this one the other day. CRC makes a MAF cleaner aerosol that I use on my cars. This one wasn't dirty looking, but I cleaned it anyway as a preventative measure.
 
I was poking around in the engine bay tonight - I disconnected some stuff to see what would happen...

Something that surprised me was that the engine stalled almost immediately when I unplugged the MAF sensor while it was running. I tried this a half dozen times and every time it stalled the engine.

Could this be my bad sensor, even though it isn't throwing a code?

Is that the behavior I should expect?

Yes, that would be expected. The ECU is actively using MAF based fueling when running. Removing it while running, removes the reference for which fueling is governed by. When the vehicle is started without the MAF in the loop, it falls back on Alpha-N fueling strategies from calibrated base tables.

I don't believe it's your MAF sensor because:
- You've now got lots of MAF related codes after pulling the sensor. Which you haven't been getting
- I think I read earlier that you ran the car without the MAF, and it stalled without it
- ST/LT fuel trims are stable. A faulty MAF generally results in A/F issues and rough running


Funny that you all are talking about Porches. I have a 996TT which I've tuned quite a bit with direct tuning tools to the DME. Big snails. Big 1000cc injectors. Big power for relatively little weight. I love the car to death for its sheer performance and rawness. I've tuned it with MAF based maps for everyday driving and protection. Also have a high octane MAFless tune for race days as the airflow exceeds what can be metered by the MAF. Swapping between this little rocket ship and LX570 bruiser for commuting is interesting. People give me room on the freeway with the LX. People don't give me slack with the Porsche, yet that doesn't matter as it's so intensely quicker than anything out there.
 
Great tastes!

To me it is the perfect two vehicle combination. The landcruiser does family hauling, long distance travel and commuter type duties; it tows the utility trailer, boat or car trailer; and is a great all around people and stuff hauler. The porsches couldn't be more different, and are just sublime for the fun stuff whether it is a quick run to town, a rip through the mountains or time on a track.

Thanks for explaining the MAF. That makes sense. I guess I need to do the work and there aren't any shortcuts.
 
If you want air/fuel ratios, buy an OBD2 WiFi ELM327 (<$20) reader and download OBD Fusion ($10) and you may need to buy the Toyota Extended PIDs pack ($10). The total for everything is <$40 and OBD Fusion has both “requested” A/F as well as “actual” A/F. (Note these are calculated not measured per se so I’m not 100% sure where the source values come from but they seem to look reasonable and I suspect are fairly accurate)
 
Will do! Thanks. I'll add it to my tool arsenal. (update: ordered EML327 on Amazon, under $15)
 
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Anyone have experience testing the integration relay? Mine is failing continuity tests between 1C-1 - 1B-8, both the battery voltage not applied and battery voltage applied to 1B-6 and 1B-7. The multimeter shows no resistance (OL - open loop). The test specified component without harness connected, so I am bench testing outside the car. I should see 10 k ohms or higher with battery disconnected and below 1 ohm with battery voltage applied to 1B-6 and 1B-7. FSM says to replace the integration relay if it fails these tests.
 
Okay, so I spent way too many hours poring over relay and wiring diagrams, and I think I can make a test rig to bypass the Integration relay.

As best I can tell, the integration relay is just an integrated circuit that simulates the function of four individual relays. I don't get why they wouldn't just have 4 separate relays... UNLESS there is something else going on inside of that black box that is not apparent from the wiring diagrams...

I'll focus on the IGN, EFI and A/F "relays" that are in the integration relay. The fourth is the horn, and as best I can tell, if I jumper it, all that will happen is that the horn will be on constantly.

For the other three, I think I can make up a test rig with four fused leads and some spade connectors, and ring terms. I'll have one lead (unfused) that comes from 1C-1 and connects to the other three leads through a bus bar. These (properly fused) leads will in turn be connected directly to 1A-4 (A/F circuit power, w/a 15A fuse), 1B-4 (EFI circuit power, w/a 25A fuse) and 1B-8 (IGN Main power, w/a 30A fuse).

I could get clever by inserting a relay in the supply lead that is triggered by the ignition, but I am hopeful that just jumpering them will work well enough to see if the integration relay is suspect. I don't plan to drive it around like this.

I don't plan to run it like this for long, but it would completely bypass the integration relay and let me see if that changes anything about the stalling behavior.

Any concerns or hesitation before I do this? Am I doing anything that raises red flags?

As an aside, if this works, it could make a good emergency tool/trail spare to limp home with if the integration relay croaks.
 
It ran fine with this jumper rig, but it still died just after 1 minute.

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Some positive diagnosis information:

With the fuel pump connector disconnected, and the fuel pump being driven directly by a variable voltage power supply, the engine runs for several minutes without stumbling, slowing or stalling.

I varied the voltage from 10.6 V down to just under 6 V to see if there were any issues, and there were none.

The implication (to me at least, please check my logic) is that if it runs with the pump driven directly, the ignition circuit is fine, and the issue is somewhere in the fuel pump circuit, upstream of the pump itself (Fuel Pump Control ECU, wiring, ECM).

The wiring doesn't seem suspect since it works reliably for a minute or so at a time, and every time.

I would like to test the FPC ECU. It has the following wires connected (numbers match terminals in wiring diagram):
  1. Black/white - power to the fuel pump
  2. White/black - ground to the fuel pump
  3. White/black - ground to chassis
  4. None
  5. White - signal wire from ECM
  6. Black - power from battery (via EFI Relay no 2, which is in turn triggered by the A/F relay)
So I can test some stuff while running with a multimeter by back probing them.

  1. Black/white - power to the fuel pump - does it lose power prior to or at the stall? If it does, why? Problem in FPC ECU or upstream?
  2. White/black - ground to the fuel pump - is ground solid and not lost prior to or during the stall (I expect this one to be fine)
  3. White/black - ground to chassis - is ground to chassis solid (if so, this shouldn't change. I expect this one to be fine)
  4. None
  5. White - signal wire from ECM - ??? - monitor to see if the pump signal is lost or continues during the stall?? What should I see?
  6. Black - power from battery (via EFI Relay no 2, which is in turn triggered by the A/F relay) - monitor during the stall to see if power is ever lost (if it is, maybe I have an issue with the relays that lead to it)
The problem with monitoring some of these is that I don't know if I am seeing a symptom or a cause.
 
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I’m guessing much overlap with >07 tundra 5.7
Second link is more relevant.
This post is interesting but doesn’t include images.
 

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