Draining battery and buzzing...
 

Greetings everyone! This past weekend I bought a 2006 Camry LE, 4 cylinder automatic. The previous owner said it had mechanical & electrical issues, it sure does!

Problem:- Battery draining / rough idle & running

Without a key in the ignition I see a CEL and Wiper Fluid indicators. Inside the engine compartment I can hear a "buzzing" sound that seem to be coming from below, between the airbox and manifold. I'm using a stethoscope probe for listening.

I used my multimeter in current mode and create a circuit between the negative post and ground. I get a reading of 4.2A spike, down to 2.7A then settles at 3A constant. The buzzing will stop if I remove the EFI relay (still no key in ignition).

When I run the motor it's rough, almost like it's missing on one of the cylinders. Idle is rough too. I can definitely understand why the battery is draining so fast.

Any suggestions? I have a scanner and can read codes. I have the negative terminal disconnected when not trying to troubleshoot.

One note, the passenger front fender was hit pretty good. That may be the reason for the windshield washer fluid low indicator. I'll check that problem next.

Thank you in advance and I hope to learn and share within this forum.
Cebu~

The wiper fluid reservoir is located in the area of the cars damage. Was the reservoir tank damaged and now leaks, the electrical plug come off the fluid level sensor, etc?

Is there just one EFI fuse or an EFI No1 and EFI No 3?

Does this car have any aftermarket alarms, door or start remotes, etc?

EFI powers:

Cruise Control
Auto trans shifting solenoids and dash gear indicator lights
ECU
Engine Immobiliser System

Thank you for the reply toyomoho. There is 1 EFI relay in the engine compartment fuse box.

No aftermarket alarms or remote start. It does have an aftermarket radio that has its fuse removed.

I’m trying to figure out where the buzzing sound comes from. Attached is a photo of my actual fuse box. I ordered the 2006 Camry wiring diagrams and Haynes manual to help troubleshoot.

Question:
Should there be any current flowing through the EFI relay circuit without a key in the ignition? Or, is a key required to complete the current flow path?

Thank you!

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Might be a stuck closed EFI relay.

EFI SOLENOID is activated by the ECU. Power to the EFI solenoid from ECU should be off with ign key off.

Power to the EFI relay SWITCH is always hot. If the switch is stuck closed then its as if the relay is on. Remove the EFI fuse to shut off power to the EFI relay switch.

I have removed the EFI fuse and the buzzing does stop. Unfortunately the other fuses I have listed also stops the buzzing.

QUESTION:
Where is the EFI solenoid located? Perhaps that itself is “stuck” in position?

Here are a few notes I took last night. Hopefully one of the manuals I ordered arrives today.

Thank you for your help, I really appreciate it.

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I forgot to mention. I bought a replacement relay for the EFI. The results were the same. I opted to try a new relay rather than borrowing from the horn relay circuit.

This update is for those of you following this thread and possibly benefit what I’ve experienced so far.

Last night I removed all harnesses one by one and checking to see if it had any effect on the “buzzing” sound whenever there was a battery connection.

It turned out the fuel injector for cylinder # 1 causes the buzzing sound and also the high parasitic current draw with no key in the ignition.

1. Initial current draw spiked to 3.9A
2. Settling current draw 2.6A
3. With # 1 fuel injector removed, 200ma. (initial and settled value)

Also, when the fuel injector is disconnected and there is no high current draw, the dashboard indicator lights do not come on. With the fuel injector connected the dash lights would come on even without a key in the ignition.

Tonight I will check the PCM signal coming from the ECM at the harness connector using a noid or test light. I’ll report back here if my findings.

Thank you everyone!


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No 1 cylinder injector is bad? The closest cylinder to timing chain.

When the ign key is on, all injectors receive 12v power via a black/red wire. The injectors electrical circuit is the completed by the ECU actions. With the ign key off, power to the injectors should be off.

The No 1 injector ground wire is also connected to the clock. Any issues with the clock?

Injector resistance is 13.4-14.2 ohm.

Can power the injector via the battery. With the built in injector plug locking clip oriented up and looking at the plug electrical terminals. The positive terminal is to the right. Don't power the injector for more the 10 seconds or the solenoid will burn out. Power the positive terminal on/off to power injector and not the negative.

The injector P/N varies with cars emissions certification being either California or Federal.

Thank you toyomoho,

With the ignition key is in the ON position all the injectors receive +12V.

With the ignition key in the OFF position all injectors no longer have +12V EXCEPT cylinder #1. It always has a constant +12V.

It's interesting you mentioned that this particular injector is tied to the interior clock.

Here's another observation:

If I have everything hooked up, including all injectors. Sometimes there is no buzzing sound and current is approximately 200ma. If I "shake" the car the buzzing will start again. The only way to get it back to no sound buzzing is to remove fuel injector # 1connector and remove the negative battery terminal from ground. Odd.

The wiring diagrams I ordered are due to arrive 4/15 to 4/122.

QUESTION:
Can you describe how the #1 fuel injector is tied to the clock? Do the two circuits share the same +12V? That would somewhat explain why there is always +12V on #1 fuel injectors connector. As I understand it the PCM signal from the ECM are ground pulses to complete the solenoid active circuit path.

I will re-measure the resistance of the injectors. I thought I was measuring Kilo Ohms not Ohms. I had measured approximately "12" for #1. The adjacent injector #2 measured about the same.

Thank you again for all your help. The shaking of the car causing the "buzzing" sound is troublesome. Almost like a pinched wire or a hot short somewhere.

The injectors always have +12V power when the EFI relay is closed. The ECU then opens and closes the return wire from the injector to complete the circuit.

The wiring diagram shows a tap off between the No 1 injector return wire and the ECU its connected to (blue wire). This tap goes to the clock.

Unlike a typically cars clocks this clock has about 15 wire connections to it. Guessing the injector connection provides input as to if the injector is operating for auto trans equipped cars. The stick shift trans equipped cars have a wire going to the clock from the speedometer.

The issue could be bad wiring, an ECU problem or something with the clock internal circuits.

Might track down the wiring at the ECU. Then disconnect the wire from No 1 injector at the ECU plug. If the injector stops working then the issue appears to be the ECU. If it keeps working then the issue is wiring between ECU or clock.