Crank and No Start SOLVED: Looks like Relay (1 Viewer)

[Romer]

EDIT: Updated thread title after replacing ignition switch and swapping relays (see post #11)

I am first reconditioning the battery as it sat for a week while on vacation.

Getting over snow bump in my driveway truck stalled on way back from airport. Started right up. Was going slow due to 2 feet of snow and going into my garage. Brake was applied

Could be vaccum related BUT

Multiple times since Saturday when parking in garage or other places press start stop button, engine shuts off but accessories stay on AND my Android Head unit reboots. So thinking not vacuum

Yes, putting in Park, foot on brake and then press button

Weird today happened twice while driving, traffic slowed quickly and pressed brake and entire dash went blank and dash lights went off. Android Head Unit went blank. Engine kept running and truck seemed to operate otherwise normally. Then few seconds later Android Head unit came back continuing with song playing, Dash came back on and status lights lit up like christmas tre for a couple of seconds before returning to normal.

Like I said, doesn't seem like a vaccum issue even though braking can change vacuum.

Have not had any start issues

Charging and conditioning battery even though seemed fine.

Thinking faulty Start Stop Switch due to accessory mode from stopping

Any relays that could cause this issue?

A few related issues in search, but didn't find anything like this combination of issues. Most have vehicle shutting off everytime and mine hasn't except for one stall.

 

[Hoosier Daddy]

Sounds like losing electrical connection intermittently. I'd check connections at battery terminals for corrosion and secure fit.

 

[Romer]

Sounds like losing electrical connection intermittently. I'd check connections at battery terminals for corrosion and secure fit.

Thanks for the input. Did that and charged battery. My batter is an X2 AGM battery from Battery plus and is 14 months old. I have put on the thought radar maybe a bad cell??? charge and conditioning showed no errors and is sitting aat 12.6V 24 hours later and 14.1V when engine is running.

Haven't driven it today so no updates. Also no codes present relateed to this. Have a few Evap codes but have been working those for a bit. They havent changed most likely Carbon Canister. So far changed Charcoal filter, Vent for tank (Have Aux tank) and just received the vapor switching valve to change that. Wanted to try those before dropping Aux tank to replace canister. These codes don't effect anything and should have no effect on issues in this thread

For this problem I did order a new ingintion switch which will be here Friday.

 

[Romer]

working my emmissions issue I just replaced the Vacuum Switch Valve on top of the engine. Two small vacuum hoses and a connector. The connector snapped into place with a click and I transfered the two hoses one ny one from the old valve to the new one to get them to the same spot. A 5 minute repaair with one 10mm bolt a connector and two small hoses. Research tells me this should have no impact on the ability to start the engine, only how it runs relative to fuel vapor management. Maybe someone here knows better

Now the Truck cranks but does not start

It cranks for a bit even after I take my finger off the start button.

Research says a bad ignition switch can cause that as well as it sends signals to lots of places not just the starter. I will try and start it again in the morning.

 

[Sandroad]

Switch is the most likely culprit from symptoms so far, it seems to me. But I'm not sure about correlations to the VSV? Water sloshing around in the sills? Do you recondition the battery while installed? I wonder what the reconditioning process does to voltage and if that's ok for the vehicle while connected? During the week recess from use, did it sit where rodents could have messed up wiring?

 

[Romer]

Thought I wwould take a moment to summarize the issue and troubleshooting I am doing
I think there are two issues going on.

First Issue: Fuel Vapor issue. Not the subject of this thread

I am troubleshooting a Fuel Vapor issue. This all happened after a filled both tanks with the extra formulated fuel which changed at stations in August/Sept? Note I have two fuel tanks. That set codes but did not effect starting. I replaced the Carbon filter, I replaced the vent filter. Codes still came back but drove fine. So I ordered the Valve Assembly, Vacuum Switching - Toyota (25860-0S010). The Vacuum Switching valve was replaced while working the second issue below and not sure if it is related to the crank but no start issue. I don’t think it should be

Codes I was getting are:

• P043E catalyst temperature sensor circuit low (bank 2 sensor 2).
• P043F catalyst temperature sensor circuit high (bank 2 sensor 2)
• P2401evaporative emission system leak detection pump control circuit low.
• P2402 evaporative emission system leak detection pump control circuit high.
• P2419 evaporative emission system switching valve control circuit low.

My guess it is the Carbon/vapor Canister above the spare tire. I wanted to try everything else before dropping the 2nd tank to replace it. None of that is supposed to do anything but disabling the ability to go into 4LO until codes are cleared. I reset the codes each time.

Second Issue: No start, but also some electrical weirdness. I think this is the Push Button Start Ignition and plan on replacing that when the part comes

For a few months the Head Unit would go blank on startup and would work after a couple of starts. Not sure if this is related, but could be accessory power issue during shut down glitching the Android Head Unit.

Last week things got weird fast

• The vehicle stalled once going over a snow bump
• Driving one day the dash and stereo went blank for a few seconds and then came back with lots of status light for a few seconds and then resumed as nothing happen. During this time the engine kept running and drove fine. This happened twice on the same drive.
• Several times over the last week when turning the car off, the vehicle went into accessory mode and the Stereo head unit rebooted. I waited for the reboot to complete and pressed the button again and it went off
• Up to here it started and drove fine everywhere
• Then one time it would not start and said check VGRS system and the OBD code reader would not connect. An hour later it started and drove fine for a couple of days with no new codes.
• Then I changed the Vacuum Switching valve. I disconnected the two pin connector. Moved the 2 hoses one at a time from the old one to the new one and then connected the two pinner to the new one. I had not started it at all that day (should have tried before replacing the part) and when I went to start it would crank but no start.
• I checked battery connections and fuses and did not find anything off. Battery is at 12.6V
• Pushing the button and releasing the engine cranks for a few before stopping
• No codes present other than the permanent ones for the emissions problem

Maybe the provides a clearer picture and what I have done so far. If I wasnt having all the other issues I would think it somehow was related to the Vaccum Switching Valve as I don't believe in Coincidences, BUT with the other things going on, I am not sure how that would cause this. I could put the old part back in, saving it just in case. I won't get the replacement switch until next week so lots of time to try something else

I did wiggle the wires on the back of the Ignition switch with no joy

 

[Romer]

Replaced Ignition switch, still cranks and no start. Not sure if it is related to the other issues or someething seperate

It was starting but acting wonky before I replaced the Vaccum Valve- swapped old one back to no effect. Is there sometype of setup required for this? I didnt see one.

I also blew the top of the fuse block off with air to remove the moab dust. The fuses were all seated so not seeing how that could have caused this

Thoughts on checking crank but no start? I will dig in more searching

 

[bloc]

When you turn on ignition but before starting, is the CEL lit up as it should be?

Any idea whether fuel pump is running? If you aren't sure you can use a mechanic's stethoscope on the fuel tank to listen for a whirring sound.

I personally think the VSV detail is coincidence.

How involved would it be to unwire the dual battery and any other electrical add-ons?

Edit: usually with a crank-no-start I'd suspect fuel pump ECU but that shouldn't have anything to do with your other quirky power cycling with engine running symptom.

 

[Romer]

When you turn on ignition but before starting, is the CEL lit up as it should be?

Any idea whether fuel pump is running? If you aren't sure you can use a mechanic's stethoscope on the fuel tank to listen for a whirring sound.

I personally think the VSV detail is coincidence.

How involved would it be to unwire the dual battery and any other electrical add-ons?

Edit: usually with a crank-no-start I'd suspect fuel pump ECU but that shouldn't have anything to do with your other quirky power cycling with engine running symptom.

Thanks for the response

Dash lights look normal

Can't hear fuel pump. That would require long stethescope

Agree on the VSV

I could disconnect the dual setup, what is your thought there?

I saw the thread on fuel pum ECU. He validated by checking signals. I will trty looking for it. Any photos under the frame where it is? Hopefully not above my skid plate

 

[bloc]

Thanks for the response

Dash lights look normal

Can't hear fuel pump. That would require long stethescope

Agree on the VSV

I could disconnect the dual setup, what is your thought there?

I saw the thread on fuel pum ECU. He validated by checking signals. I will trty looking for it. Any photos under the frame where it is? Hopefully not above my skid plate

Yeah I was thinking have someone else cycle the power while you use the mechanic's stethoscope from under the rig. It should run for a couple seconds to prime the system when you first turn the ignition on, then shut off while it waits for you to hit start.

From memory the fuel pump ecu is on top of the frame rail roughly under the driver's side rear door. You get access from the outside of the frame so your skids should be ok, but sliders could be an issue I guess.

 

[Romer]

I is fortunate that Toyota made many of the Relays the same in the engine bay fuse block
Part No.: 90987-02027 RELAY - Replaced by: 90080-87026

I went and swapped pairs of these identical Relays and tried starting it each time

When I swapped the ST CUT relay with the Deicer Relay the truck started right up. I drove it for a bit and went through several more start cycles and it worked fine

I am still a bit confused as I understand the function of this relay is to remove the Voltage from the Starter which would result in No crank

I believe the other "wonky issues" described in the first post are still the Push Stop Switch. Time will tell

I ordered 3 OEM relays to replace the one now in the deicer slot and to have a couple of spares

Anyone understand how the ST CUT Relay would cause a Crank, but no start?

 

[Romer]

A google AI Bot had this to say. Not sure how accurate this is

If your car is experiencing a "ST CUT" relay issue with "crank no start" symptoms, it means that when you turn the key to start the engine, the starter motor cranks (turns over), but the engine doesn't actually ignite and start running; this is usually a sign that the "starter cut" relay, which is responsible for cutting power to the starter motor once the engine starts, is faulty and not properly disengaging, preventing the engine from firing up properly.

 

[bloc]

I is fortunate that Toyota made many of the Relays the same in the engine bay fuse block
Part No.: 90987-02027 RELAY - Replaced by: 90080-87026

I went and swapped pairs of these identical Relays and tried starting it each time

When I swapped the ST CUT relay with the Deicer Relay the truck started right up. I drove it for a bit and went through several more start cycles and it worked fine

I am still a bit confused as I understand the function of this relay is to remove the Voltage from the Starter which would result in No crank

I believe the other "wonky issues" described in the first post are still the Push Stop Switch. Time will tell

I ordered 3 OEM relays to replace the one now in the deicer slot and to have a couple of spares

Anyone understand how the ST CUT Relay would cause a Crank, but no start?

Looking at the wiring diagrams I'm not sure what the purpose of the ST_CUT relay is. The starter can still get a start signal direct from the BCM on the STR pin.. the ST-CUT relay just switches the STR2 pin signal from the BCM. Even outside of the BCM there is a STA pin on the ECU that, again, bypasses the ST-CUT relay.

Not that any of this dismisses the fact that the truck now starts.. just that I don't really know what that relay is supposed to do.

I'm attaching some relevant stuff from the EWD and FSM

 

[Romer]

The one thing that was interesting when it was Crank and no start is when I stopped pushing the start button, the starter would continue to crank for 10 seconds or so. I didn't know if that was normal when it doesn't fire up or not.

I would like to know more what it does as well to make sure this makes sense and it did not temporarily heal itself

I would bet money that it isnt the De-icer relay. I ordered a probe I saw in one of the videos in the threads here that will make it easier to test the relay and I have some new Denso relays coming around the weekend. This probe allows you to inject a voltage so I can engage the relay.

https://www.amazon.com/gp/product/B00UZ940ES/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

 

[bloc]

Many modern vehicles do continue to crank until starting even after you stop pressing the button, but I haven't confirmed for sure that my 200 does. What gets me is that should prevent a faulty start switch killing an otherwise good relay. It's not like these two parts are directly connected.. unless a bad start switch caused the BCM to do weird things to the relay?

I've been digging for a while trying to determine the function of the STR and STR2 leads from the BCM, but no luck so far.

 

[Romer]

I appreciate your looking. I found this in the FSM. Still not clear how this could have caused this

 

[Sandroad]

I appreciate your looking. I found this in the FSM. Still not clear how this could have caused this

View attachment 3776133

Here's my take. It looks to me like you had a defective (or loose) ST CUT relay. My read is that when activated by the start sequence, it cuts power to much of the dash to "prevent flickering". After the engine starts, that relay is deactivated and the rest of the dash and the head unit lights up. So its purpose is not to cut power to the starter, but rather to cut power to some systems while the starter is operating. That also could explain your other wonky electrical issues, since a defective relay may have been operating at the wrong time (over bumps, etc) and shutting off or flickering part of the dash and head unit. I wonder if it could even keep accessories/head unit from properly shutting off? Further, I bet that if the ECM doesn't detect proper operation of that relay, it won't let the engine start. I suspect replacing that relay with a new one (and returning the deicer relay to its proper home) will fix all the problems. (I hope )

 

[Romer]

Here's my take. It looks to me like you had a defective (or loose) ST CUT relay. My read is that when activated by the start sequence, it cuts power to much of the dash to "prevent flickering". After the engine starts, that relay is deactivated and the rest of the dash and the head unit lights up. So its purpose is not to cut power to the starter, but rather to cut power to some systems while the starter is operating. That also could explain your other wonky electrical issues, since a defective relay may have been operating at the wrong time (over bumps, etc) and shutting off or flickering part of the dash and head unit. I wonder if it could even keep accessories/head unit from properly shutting off? Further, I bet that if the ECM doesn't detect proper operation of that relay, it won't let the engine start. I suspect replacing that relay with a new one (and returning the deicer relay to its proper home) will fix all the problems. (I hope )

sounds reasoable. I appreciate the input!

The ST Cut, Deicer and several other relays are all the same part number.

 

[bloc]

I agree that does sound plausible. I just can’t wrap my head around why the st-cut relay is even needed.. if it’s just passing along a signal to the BCM.

 

[Sandroad]

I agree that does sound plausible. I just can’t wrap my head around why the st-cut relay is even needed.. if it’s just passing along a signal to the BCM.

Reading the EWD and description of the start sequence is a hoot. My ‘46 Jeep had 3 components to starting; the battery, a heavy duty foot-operated switch, and the starter motor. The ignition switch for coil power was only needed if you actually wanted the engine to run.