I'm having a similar issue. Did you also replace relays or just fuses? Odd an unsatisfying solution. Did the toyota appointment solve anything? Did the fuse fix resolve the dash light or gauge behavior? How did you determine it fixed the issue? Which ground connections did you clean?
Solved - GX470 - No Engine Light
- Thread starter stoshzack
- Start date
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My GX470 has been doing this over the past week. I cleaned all battery connections and it still came back. Each time it occurred, it was accompanied by the backlighting in the dash being turned off - the warning lights would still turn on, but the cluster was otherwise dark. Several times it also threw camshaft position sensor codes after it started up.
It ended up being the starter relay, but the relay itself was not bad. I figured this out as the relay wasn't clicking in the underhood fuse box when I turned the key. I removed the relay, added some dielectric grease to the relay pins, and re-installed it and it's started up fine for a couple of days now. I went ahead and ordered another starter relay from Bell Lexus and will throw it in the glovebox for in case this happens again.
It's been HOT here this week (heat index of 120F+ some days). I think the extreme heat for some reason causes intermittent connection issues in the fuse and relay box in these rigs. Probably a good idea to remove and reinstall suspect fuses and relays and put some dielectric grease on them. I don't think any of them need to be replaced though. But, all of these problems are clearly due to intermittent poor electrical connections.
It ended up being the starter relay, but the relay itself was not bad. I figured this out as the relay wasn't clicking in the underhood fuse box when I turned the key. I removed the relay, added some dielectric grease to the relay pins, and re-installed it and it's started up fine for a couple of days now. I went ahead and ordered another starter relay from Bell Lexus and will throw it in the glovebox for in case this happens again.
It's been HOT here this week (heat index of 120F+ some days). I think the extreme heat for some reason causes intermittent connection issues in the fuse and relay box in these rigs. Probably a good idea to remove and reinstall suspect fuses and relays and put some dielectric grease on them. I don't think any of them need to be replaced though. But, all of these problems are clearly due to intermittent poor electrical connections.
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I initially suspected the relay so I swapped relays. In my case its not the SRT relay because it just did the same thing again AFTER the swap.
I had an identical issue on my FJ80 now that I think of it: Old aftermarket BOSCH starter that would heat soak after driving on hot days while parked after driving and not crank at all until it cooled off (usually after leaving the hood open for a bit while I scratch my head)
So far the only common thing I've done is to open the hood, and then it eventually cranks and its been HOT here lately, it only happens after you drive it and park it (hence the soak), and eventually cranks after I open the hood. Hrmm starter heat soak? The solution for the FJ80 was new OEM starter.
@stoshzack, did the weather change in your area per chance? (e.g. was it hot when it was happening, and Cooler after cleaning the relays)?
I had an identical issue on my FJ80 now that I think of it: Old aftermarket BOSCH starter that would heat soak after driving on hot days while parked after driving and not crank at all until it cooled off (usually after leaving the hood open for a bit while I scratch my head)
So far the only common thing I've done is to open the hood, and then it eventually cranks and its been HOT here lately, it only happens after you drive it and park it (hence the soak), and eventually cranks after I open the hood. Hrmm starter heat soak? The solution for the FJ80 was new OEM starter.
@stoshzack, did the weather change in your area per chance? (e.g. was it hot when it was happening, and Cooler after cleaning the relays)?
Have you verified that the relay is clicking? If you can feel the relay click (put your finger on it when someone turns the key to start to check), then it's definitely not the relay. If it's not clicking, it's the relay or the pins/connections beneath the relay.
FYI I have had the starter crap out out in my GX before - it would make the typical "click" noise (fuse box relay and the starter solenoid, which is just a big relay) but not turn over. It did not have any of the unusual gauge cluster behavior that the starter relay issue caused. The starter relay must trigger a lot of other downstream electrical systems/computers, while the starter solenoid must not.
If you are just having the no-start, no weird instrument cluster behavior, no weird codes, and have verified that starter relay is clicking, then yes it's probably your starter. Mine died at around 135K miles; I replaced it with a Denso reman from Rock Auto.
Here was the conclusion to my heat soak/bad starter on my FJ80: 91 FJ80: Won't start: no crank, CEL on, Good battery, FP flowing - https://forum.ih8mud.com/threads/91-fj80-wont-start-no-crank-cel-on-good-battery-fp-flowing.1187274/page-2
Yes, check if the STR relay physically/audibly clicks when you have a no-crank condition. Mine was 100% NOT clicking at the intermittent no crank AND was causing the weird cluster behavior, removing/reinstalling it with some dielectric grease seems to have fixed the problem.
I also have a SAIS bypass that has some wires linked into the starter relay, they never caused a problem before but certainly could have caused it now.
While the 2UZ starter does wear out eventually, IMO I don't see heat soak being a huge problem. The starter is in the V of the engine and gets very hot most of the time - added heat outside the rig probably won't make it any hotter than it already is from just normal driving.
Ok: Just took the car for a trip. Drove great. After about 1h in the sun parked, we came back and it didn't crank! Opened the hood, let it 'air out' for 10-20 minutes, cranks great.
This is exactly the problem I had on the FJ80 with the going-bad BOSCH after market starter in it. Or the heat soak is in the relay box. I still haven't had a chance to check relay activation during no crank conditions. I hope to try that out in about 1h after the condition starts again.
What sucks about heat soak is your car wont start, you open the hood, fiddle around, and then the car starts. Then you conclude whatever you jiggled needs cleaning or is loose and in fact it its a temperature issue.
I'm going to confirm the STR relay condition next time it happens but I think this is the right direction.
This is exactly the problem I had on the FJ80 with the going-bad BOSCH after market starter in it. Or the heat soak is in the relay box. I still haven't had a chance to check relay activation during no crank conditions. I hope to try that out in about 1h after the condition starts again.
What sucks about heat soak is your car wont start, you open the hood, fiddle around, and then the car starts. Then you conclude whatever you jiggled needs cleaning or is loose and in fact it its a temperature issue.
I'm going to confirm the STR relay condition next time it happens but I think this is the right direction.
The solenoid on a 2UZ starter is part of the whole starter unit. Unfortunately it requires pulling the intake manifold, but since you have a non-VVTI GX, you won't have to mess with the SAIS tubing like I did. It's probably half a day of work, and requires also removing some coolant crossover tubes. The 2UZ starter seldom lasts more than 200K, so it's totally plausible that is your issue and it's coincidental with the summer heat. Checking the relay next time will help you verify the problem.
- Thread starter
- #31
Just saw these posts. My problem has not come back. My problem was related to one of the 7.5 amp fuses (changed them both in engine bay and cabin - not sure which exact one). Never took it in to Toyota because the problem has not happened again.
- Thread starter
- #32
FYI - I cleaned all major ground connections in engine bay. One right off the battery to fender. Two on the engine block I think. One on the frame rail between engine and battery. I knew it resolved the issue because it starts every time now on first ignition turn.
- Thread starter
- #33
I read that a bad cam shaft sensor or frayed wires to the cam shaft sensor will mimic the exact conditions I had. I ruled out the cam shaft sensor because I did not have any error codes related to it and I visually inspected the wires.
- Thread starter
- #34
Lastly - I had changed out my starter 3 years ago (also around 135K) with a reman OEM unit from Toyota. I figured that was not the problem based on how recently I replaced it and the fact that when the “engine” light came on (after turning the key in the ignition), it would start every time.
- Thread starter
- #35
Well - I guess I have one more post. I also learned when researching this that a bad motor in one of the side mirrors can mimic the conditions I had. The solution is to move the mirror switch to the middle position (so the side mirrors do not move when you shift into reverse and blow the fuse constantly) and change out the corresponding fuse. I don’t think this was my problem as both of my side mirror motors still work. However, moved my switch to the middle anyway to be safe.
Fuses blowing when the mirrors move is definitely an issue!
My rig has been good all week regarding the no-start issue, since I jiggled the starter relay and added some dielectric grease. It's also been hot, albeit not quite as hot as it was before. Previously, it had the no-start issue around daily. However it seems there are multiple issues that can cause this behavior.
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OK! Happened again today and I have more info. I was off, and you guys were on target: this not the starter, but (at least in my case) this is a temperature dependent intermittent failure that solves when something in the fuse box cools down. The STR relay wasn't clicking when trying to crank, but also nothing else in the relay box in the engine bay was clicking when the ignition is ON, and I also noticed the CEL is not illuminating when the ignition switch is ON when the bay is hot (thank you for this pointer, I did not noticed this before). (When the bay cools down this light turns back on when ignition sw is ON).
Opening the hood and fuse box and the CEL comes back on and the car starts very shortly after a brief cooldown.
Because the issue responds so directly to temp changes in the engine bay, I don't think my ignition switch is the issue. Given the relationship to the CEL, this was the suspect pathway:
Battery
↓
20A EFI fuse
↓
EFI main relay
↓
ECM +B and +B2 power
↓
ECM boots
↓
ECM commands the CEL at key ON
Therefore these are the fuses and relays to inspect:
- 30A AM2 fuse — Toyota 90982-08283 (Good)
- 20A EFI fuse — Toyota 90982-09011 (Rusted/deformed/discolored)
- 10A EFI No. 2 fuse — Toyota 90982-09009 (Good)
- EFI main relay — Toyota 90987-02022 (Good)
Removing the 20A EFI fuse replicates the 'heat soak' condition: No CEL when Ignition sw is ON, and no crank! (or ST clicking etc). So not a heat soaked starter (thank god, though I had that exact problem on my 80) but a heat soaked faulty fuse.
If I had to 'needle in a haystack' this, I could have observed the top of the fuses and maybe noticed the slight discoloration on the pin of the 20A efi relay.
Ok problem solved hopefully?! Any clue what could cause this? Single blade discoloration indicates bad connection = heat? Its also deformed and wont go into other fuse sockets easily. Was it deformed and had a bad connection or did the heat deform it. I guess I will replace and monitor for the symptom to develop on its own again?
Opening the hood and fuse box and the CEL comes back on and the car starts very shortly after a brief cooldown.
Because the issue responds so directly to temp changes in the engine bay, I don't think my ignition switch is the issue. Given the relationship to the CEL, this was the suspect pathway:
Battery
↓
20A EFI fuse
↓
EFI main relay
↓
ECM +B and +B2 power
↓
ECM boots
↓
ECM commands the CEL at key ON
Therefore these are the fuses and relays to inspect:
- 30A AM2 fuse — Toyota 90982-08283 (Good)
- 20A EFI fuse — Toyota 90982-09011 (Rusted/deformed/discolored)
- 10A EFI No. 2 fuse — Toyota 90982-09009 (Good)
- EFI main relay — Toyota 90987-02022 (Good)
Removing the 20A EFI fuse replicates the 'heat soak' condition: No CEL when Ignition sw is ON, and no crank! (or ST clicking etc). So not a heat soaked starter (thank god, though I had that exact problem on my 80) but a heat soaked faulty fuse.
If I had to 'needle in a haystack' this, I could have observed the top of the fuses and maybe noticed the slight discoloration on the pin of the 20A efi relay.
Ok problem solved hopefully?! Any clue what could cause this? Single blade discoloration indicates bad connection = heat? Its also deformed and wont go into other fuse sockets easily. Was it deformed and had a bad connection or did the heat deform it. I guess I will replace and monitor for the symptom to develop on its own again?
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