2009 200 series shut down at stop light. Now NOTHING

[kurtnkegger]

Wiring diagrams I've seen list power as VCV1 and VCV2. I am using that as my 5 volt reference, though theres nothing listed as a 5v wire.

vcv1 goes to the vvt sensors bank 2 intake and exhaust
vcv2 goes to the vvt sensors bank 1 intake and exhaust, Air swith valve bank 1, can shaft position sensor, and crankshaft position sensor.

I cant get an ohm reading with my little fluke multimeter when I try to get ohms from pin6 and 14 to the chassis ground on pin 4. It automatically jumps to voltage when I try that. 6 and 14 together give me 62 ohms

 

[DaveInDenver]

Just checked on my 2008 Tacoma. Pins 6 to 14 shows 62.5 ohms with key off. Had a "duh" moment remembering this is what you'd expect with both 120 ohm terminations on each end, e.g. two 120 ohms in parallel.

Key on the termination resistance is meaningless, it showed several meg-ohm but with all the drivers and receivers active that's what you'd expect.

Key off pin 6 and pin 14 both show 1.98V relative to ground.

With ignition on exactly 1V measuring voltage between pin 6 and 14. Low showed ~2V and high ~3V relative to ground on a RMS multimeter. No discernible AC voltage or frequency with a DMM, which isn't surprising. Would need a 'scope and it's too friggin hot to deal with that.

 

[RossM]

If you have already done so, please forgive me reposting this.

Check grounds at and around battery. Any auxiliary wiring? Lights, other accessories? Check there first. Check battery itself as well. My folks had a 2008 that seemed really sensitive to voltage. Issue was intermittent to say the least.

 

[kurtnkegger]

Thanks Ross, I replaced the battery this morning, and have checked grounds showing continuity between the battery, grounds and even from the grounds to the block. battery- to the block. Completely stock 200 so no addtional draw on the system than Mr Toyota planned.

I finally disconnected the battery completely and will try again in the AM. I've gone through a gallon of water and a ton of brain damage today and finally had to give it up.

Please keep ideas coming I'll try about anything...

By the way Dave, I borrowed a meter from my son and got around 250 ohms between 6 and ground and 14 and ground

 

[White Stripe]

Seems like a bad ground or broken wire. It's a vehicle stored somewhere where mice can get to it? Has it had any work done to it recently before this?

 

[kurtnkegger]

It's always parked outside, but every wire looks good, every loom looks fine. Even the loom holders around the block are in tact and keeping the wires away from rubbing on the block or other components. No evidence of rodent chew on anything that I've seen.

I did replace the TPMS sensors on all 5 tires last weekend, but went smoothly and the vehicle talked to, and accepted the new TPMS serial numbers and reported all back to the computer. Warnings and codes disappeared after the swap

 

[White Stripe]

It's always parked outside, but every wire looks good, every loom looks fine. Even the loom holders around the block are in tact and keeping the wires away from rubbing on the block or other components. No evidence of rodent chew on anything that I've seen.

I did replace the TPMS sensors on all 5 tires last weekend, but went smoothly and the vehicle talked to, and accepted the new TPMS serial numbers and reported all back to the computer. Warnings and codes disappeared after the swap

Well keep in mind Colorado has mag chloride too. If a electrical plug seal fails and mag chloride or salt brine gets in it can cause a pin to corrode. I would say the check engine light not coming on is the biggest clue in my opinion. Usually means the ecu isn't getting power properly. Maybe you knew that already.

 

[kurtnkegger]

I don't know if this is a clue, or just coincidence, but my wife said a few days prior when she was listening to kool105 radio the music would shut down for about 5 seconds like the signal was lost. She put up with it for a little while because it would happen a time or two on each song. She changed stations and music was fine, but when she changed back, the same thing would happen. I think if it were a symptom of a problem it would follow any station regardless. Anyway, thought I would throw this out to you to see if it may be a hidden clue.

 

[DaveInDenver]

The radio, interesting. Does the truck have the OEM radio? If it's been replaced are there adapters involved?

Does it do other things such as navigation, setting vehicle functions or displaying cameras or system status, etc?

Oh, also, is KOOL 105 an HD radio station or analog?

Maybe the truck just wants a different radio station. It is getting to be a teenager after all, temperamental and all that.

 

[kurtnkegger]

Factory radio. All functions through the center screen are active there. Radio, Navigation, rear camera, blah,blah,blah. I don't know how KOOL105 is broadcast.

On a side note, our Sequoia would switch to a Mexican station when it was cold outside. Only at start-up. I figured it was begging for a warmer climate,

 

[HDavis]

I don't know if this is a clue, or just coincidence, but my wife said a few days prior when she was listening to kool105 radio the music would shut down for about 5 seconds like the signal was lost. She put up with it for a little while because it would happen a time or two on each song. She changed stations and music was fine, but when she changed back, the same thing would happen. I think if it were a symptom of a problem it would follow any station regardless. Anyway, thought I would throw this out to you to see if it may be a hidden clue.

Yep! That is totally a clue! When our battery was going bad on our 200 it would do the same thing. The whole infotainment screen would cut out and then come back on. I thought my wife was crazy because it never happened to me and I checked the battery cables and it was fine, then it happened to me. I figured I would replace that battery to see if that would fix it and it has never happened since. I would wager it's the alternator and Battery maybe.

 

[kurtnkegger]

I changed a new battery yesterday morning and no change. I diconnected the battery (both terminals) overnight to hopefully purge all electrons from the system. hooked the battery up this morning....no change.

I'm going over the wiring (again) looking for problems. Hooked a vvt sensor wire to my meter and showing 1.4 volts.

Still dead in the water.....

 

[DaveInDenver]

Hooked a vvt sensor wire to my meter and showing 1.4 volts.

Do you have a good value to compare this to? It looks like it's differential so that may well be right.

I don't have the wiring diagram for a 200 series but using my Tacoma for reference the VVT sensor VVL+ and VVL- (for left side in this example) are direct to/from the ECM and the sensor VC goes back to the ECM.

This common VC is either +12V or zero, the FSM isn't clear that I can find. I *think* it may be a zero based on the way it's made up in the harness, with junction splices being typical of grounds elsewhere. But that's only wild speculation on my part.

This VC is co-located in the harness with VC signal for the throttle body and vapor canister pump (again, on my 1GR, just for example). Point there is there's a few places that could be affecting the VC signal itself and I would assume something similar is true of the 200 series.

 

[DaveInDenver]

Well, FWIW, I did start following through the P0340 DTC steps in my Tacoma FSM.

Looks like the VVT signal is 5V and the reference is body ground, e.g. zero.

Also looks to imply the lowest voltage the control system will still function is 8V.

 

[kurtnkegger]

My throttle body doesn't share the VC chain. I thought it did, but on second look ended up the power wire is a blue/black wire where the VC wires are blue. My MAF sensor is wire loom all the way to the plug, but probing that, It's power is to the B+, so a 12volt sensor

 

[kurtnkegger]

Well, I think it's smart to realize when I'm in over my head. I've done my due dilligence to look for all the shade tree solutions and think it's smart to tap out. Japanese Auto is just down the road and think that is where I'm going to go.

Thanks for all the suggestions and help.

 

[nakman]

late to this.... what about a bad tail light bulb? I or the switch for the brake pedal being depressed? On a 3rrd gen 4runner for example, if you have a bad brake light it won't start, as the circuit that says it's ok to hit the starter needs that brake signal input, and it runs through the actual light bulb.

 

[kurtnkegger]

Haha! If your mission was to make me run outside and check the brake lights...Mission accomplished Sir!

 

[kurtnkegger]

Just to wrap this thread up for future seekers who might be experiencing what I had...

I called Japanese Auto to schedule an appointment. They were booked out a couple of weeks before I could even get the truck in. They recommended Seyfer Auto on 45th and Harlan, I was able to set an appointment for Wednesday (I called Monday morning) I got a tow to their garage that Monday in case of a cancellation or a bump up in work schedule.

Wednesday early, I received a call from Seyfer that they had the problem diagnosed. After tracking down the same sensors I had identified as sharing th VC line, they too could only get 1.9volts max from that circuit. They have a service where they call in to tech help. Tech help eventually suggested they unplug the ACIS at the rear of the engine, and the 5v reference jumped to life!

I never did see where that air actuator shared the same 5v VCV lines but non-the-less, voltage returned.

I had them replace with a Toyota part rather than aftermarket. They had to remove the intake plenum and gaskets to get to the part, but back on the road and back home.

Thanks Y'all for the help!

 

[DaveInDenver]

The VSV for ACIS doesn't share the VC line in the external harness. That's kind of a weird.

The ACIS VSV is an actuator that has +B on high side (shared with a bunch of stuff) and control on the low side. It's not a sensor.

The +B is generated thru the EFI relay.

The other side of the ACIS connector is the MREL line, which is the signal that triggers the EFI relay coil, at least on a 1GR Tacoma (so major difference).



I haven't been able to find a troubleshooting section for the ACIS itself, but still looking.

Are they saying the ACIS is causing the issue or the connector and harness to it? It may be ACIS through some internal unknown circuit in the ECU itself and without schematics (reverse engineering) or given troubleshooting steps you'd never figure that out.

But MREL is a critical signal in the way the control system works, it has to hold up across the cranking, for example, because you get into a circular logic situation with the ECU, immobilizer and various systems falling into line logically.

So dang that's a deep one. Working perhaps starting from the EFI relay and fuse on the power side. If MREL is not triggered then downstream things are affected. The mechanic may never know why without tech support, though.

Got to file this into the memory banks for future use!