2002 Avalon XLS, ABS light and EFI relay

A strange electrical problem has developed occasionally after washing or rain.
First noticed loud ticking under hood after car was shut down. Turned out to
be the EFI relay. Unplugging relay and sitting overnight seemed to clear
problem. Stangely associated with this incident was the ABS light blinking
continually that would sometimes extinguish after the first firm braking.
All braking appeared normal at all times. This happened twice about 4 months
ago both after washing or rain, but did not happen again until yesterday
despite numerous heavy rains and car washes. Replacing the EFI relay did not
stop the ticking when it occured before or now.

Yesterday the problem arose again after a car wash. This time pulling relay
overnight did not stop the ticking. After driving and playing around a bit
the ticking stopped when key was moved to accessory position and back to off..
strangely. But now I notice that the ABS light blinks continually when key
is in accessory position. The clicking has stopped, but the ABS light now
still blinks at start and still extinguishes after first braking.

I feel like this problem is moisture related, but I can't understand the
relationship between an EFI relay and ABS light. Any insight would be
appreciated before I take it to the dealership.

"erom43" <u27345@uwe> wrote in message news:67131155944dc@uwe...[color=blue]
>A strange electrical problem has developed occasionally after washing or
>rain.
> First noticed loud ticking under hood after car was shut down. Turned out
> to
> be the EFI relay. Unplugging relay and sitting overnight seemed to clear
> problem. Stangely associated with this incident was the ABS light
> blinking
> continually that would sometimes extinguish after the first firm braking.
> All braking appeared normal at all times. This happened twice about 4
> months
> ago both after washing or rain, but did not happen again until yesterday
> despite numerous heavy rains and car washes. Replacing the EFI relay did
> not
> stop the ticking when it occured before or now.
>
> Yesterday the problem arose again after a car wash. This time pulling
> relay
> overnight did not stop the ticking. After driving and playing around a
> bit
> the ticking stopped when key was moved to accessory position and back to
> off..
> strangely. But now I notice that the ABS light blinks continually when
> key
> is in accessory position. The clicking has stopped, but the ABS light now
> still blinks at start and still extinguishes after first braking.
>
> I feel like this problem is moisture related, but I can't understand the
> relationship between an EFI relay and ABS light. Any insight would be
> appreciated before I take it to the dealership.
>[/color]

I think you have 2 separate problems. The flashing ABS light is telling you
that the ABS portion of your braking system is inoperative. Since the
problem occurs when the car is wet, I should suspect water in a speed sensor
connector or near the ABS relay. A code scan will help point the technician
to the trouble spot.

The EFI relay clicking may be caused by the ignition switch or by water near
the junction block where the relay is located. If it is the same block as
the ABS relay, I'd check it for water intrusion.
--

Ray O
(correct punctuation to reply)

Ray O wrote:[color=blue][color=green]
>>A strange electrical problem has developed occasionally after washing or
>>rain.[/color]
>[quoted text clipped - 25 lines][color=green]
>> relationship between an EFI relay and ABS light. Any insight would be
>> appreciated before I take it to the dealership.[/color]
>
>I think you have 2 separate problems. The flashing ABS light is telling you
>that the ABS portion of your braking system is inoperative. Since the
>problem occurs when the car is wet, I should suspect water in a speed sensor
>connector or near the ABS relay. A code scan will help point the technician
>to the trouble spot.
>
>The EFI relay clicking may be caused by the ignition switch or by water near
>the junction block where the relay is located. If it is the same block as
>the ABS relay, I'd check it for water intrusion.[/color]


Thank you. This may be two separate problems, however, they have always
occured together. If you are correct, then it is possible that the same area
that gets wet affects both sensors. Can you tell me exactly where I should
look for the water intrusion?

PS. Today the car ran normally with no ABS lights or relay clicking. I
suspect the problem area has dried up and sensors are acting normal.

"erom43" <u27345@uwe> wrote in message news:6714cafb13482@uwe...[color=blue]
> Ray O wrote:[color=green][color=darkred]
>>>A strange electrical problem has developed occasionally after washing or
>>>rain.[/color]
>>[quoted text clipped - 25 lines][color=darkred]
>>> relationship between an EFI relay and ABS light. Any insight would be
>>> appreciated before I take it to the dealership.[/color]
>>
>>I think you have 2 separate problems. The flashing ABS light is telling
>>you
>>that the ABS portion of your braking system is inoperative. Since the
>>problem occurs when the car is wet, I should suspect water in a speed
>>sensor
>>connector or near the ABS relay. A code scan will help point the
>>technician
>>to the trouble spot.
>>
>>The EFI relay clicking may be caused by the ignition switch or by water
>>near
>>the junction block where the relay is located. If it is the same block as
>>the ABS relay, I'd check it for water intrusion.[/color]
>
>
> Thank you. This may be two separate problems, however, they have always
> occured together. If you are correct, then it is possible that the same
> area
> that gets wet affects both sensors. Can you tell me exactly where I
> should
> look for the water intrusion?
>
> PS. Today the car ran normally with no ABS lights or relay clicking. I
> suspect the problem area has dried up and sensors are acting normal.[/color]

Look in the fuse box under the hood. Before you remove the cover, make sure
it is on correctly and there are not cracks in the cover.
--

Ray O
(correct punctuation to reply)

Ray O wrote:[color=blue][color=green][color=darkred]
>>>>A strange electrical problem has developed occasionally after washing or
>>>>rain.[/color][/color]
>[quoted text clipped - 25 lines][color=green]
>> PS. Today the car ran normally with no ABS lights or relay clicking. I
>> suspect the problem area has dried up and sensors are acting normal.[/color]
>
>Look in the fuse box under the hood. Before you remove the cover, make sure
>it is on correctly and there are not cracks in the cover.[/color]



I have checked fuse box cover and integrity and it seems solid. I could find
no evidence of leaks or even water marks in the area. Is there somewhere
else that water could be getting in to cause these problems?

I have heard of others who had water getting in a cracked tail light lens and
causing strange unrelated electrical anomolies, but I checked every light
cover on the car, and they all looked clean and solid with no moisture inside.
I checked the primary sources of water leaks (hood seam, light covers, trunk
seam, wiper recess etc.), but could not find any evidence of leakage. There
are some water marks on the firewall area, but those look like they came from
splashing from the undercarriage area. Two of these incidents came after car
washing only with no splashing from puddles etc.

Anyone have any ideas where I could look for possible causes? Any idea on
what kind of short or leakage could cause these two unrelated problems?
Possibly a wire bundle that got knicked somewhere? Possibly the leads to
these either EFI or ABS sensors? Any further troubleshooting ideas would be
appreciated. Thanks.

--
Message posted via CarKB.com
[url]http://www.carkb.com/Uwe/Forums.aspx/toyota/200610/1[/url]

"erom43 via CarKB.com" <u27345@uwe> wrote in message
news:6720ece83ead8@uwe...[color=blue]
> Ray O wrote:[color=green][color=darkred]
>>>>>A strange electrical problem has developed occasionally after washing
>>>>>or
>>>>>rain.[/color]
>>[quoted text clipped - 25 lines][color=darkred]
>>> PS. Today the car ran normally with no ABS lights or relay clicking. I
>>> suspect the problem area has dried up and sensors are acting normal.[/color]
>>
>>Look in the fuse box under the hood. Before you remove the cover, make
>>sure
>>it is on correctly and there are not cracks in the cover.[/color]
>
>
>
> I have checked fuse box cover and integrity and it seems solid. I could
> find
> no evidence of leaks or even water marks in the area. Is there somewhere
> else that water could be getting in to cause these problems?
>
> I have heard of others who had water getting in a cracked tail light lens
> and
> causing strange unrelated electrical anomolies, but I checked every light
> cover on the car, and they all looked clean and solid with no moisture
> inside.
> I checked the primary sources of water leaks (hood seam, light covers,
> trunk
> seam, wiper recess etc.), but could not find any evidence of leakage.
> There
> are some water marks on the firewall area, but those look like they came
> from
> splashing from the undercarriage area. Two of these incidents came after
> car
> washing only with no splashing from puddles etc.
>
> Anyone have any ideas where I could look for possible causes? Any idea on
> what kind of short or leakage could cause these two unrelated problems?
> Possibly a wire bundle that got knicked somewhere? Possibly the leads to
> these either EFI or ABS sensors? Any further troubleshooting ideas would
> be
> appreciated. Thanks.
>
> --
> Message posted via CarKB.com
> [url]http://www.carkb.com/Uwe/Forums.aspx/toyota/200610/1[/url]
>[/color]
I am not aware of any widespread problems like you are describing. By any
chance was the car ever in an accident? Are there any aftermarket
accessories installed like a remote starter, fog lights, satellite radio,
etc? If there is a yes to any of those questions, I'd start checking the
areas where the factory wiring was disturbed. If no, then all I can suggest
is to try wiggling wires and wire looms when the problem occurs or take it
to a dealership for diagnosis.
--

Ray O
(correct punctuation to reply)

Make sure tire wear is even and pressure in tires is same all around.


"erom43" <u27345@uwe> wrote in message news:67131155944dc@uwe...[color=blue]
>A strange electrical problem has developed occasionally after washing or
>rain.
> First noticed loud ticking under hood after car was shut down. Turned out
> to
> be the EFI relay. Unplugging relay and sitting overnight seemed to clear
> problem. Stangely associated with this incident was the ABS light
> blinking
> continually that would sometimes extinguish after the first firm braking.
> All braking appeared normal at all times. This happened twice about 4
> months
> ago both after washing or rain, but did not happen again until yesterday
> despite numerous heavy rains and car washes. Replacing the EFI relay did
> not
> stop the ticking when it occured before or now.
>
> Yesterday the problem arose again after a car wash. This time pulling
> relay
> overnight did not stop the ticking. After driving and playing around a
> bit
> the ticking stopped when key was moved to accessory position and back to
> off..
> strangely. But now I notice that the ABS light blinks continually when
> key
> is in accessory position. The clicking has stopped, but the ABS light now
> still blinks at start and still extinguishes after first braking.
>
> I feel like this problem is moisture related, but I can't understand the
> relationship between an EFI relay and ABS light. Any insight would be
> appreciated before I take it to the dealership.
>[/color]

Ray O wrote:[color=blue][color=green][color=darkred]
>>>>>>A strange electrical problem has developed occasionally after washing
>>>>>>or[/color][/color]
>[quoted text clipped - 33 lines][color=green]
>> be
>> appreciated. Thanks.[/color]
>
>I am not aware of any widespread problems like you are describing. By any
>chance was the car ever in an accident? Are there any aftermarket
>accessories installed like a remote starter, fog lights, satellite radio,
>etc? If there is a yes to any of those questions, I'd start checking the
>areas where the factory wiring was disturbed. If no, then all I can suggest
>is to try wiggling wires and wire looms when the problem occurs or take it
>to a dealership for diagnosis.[/color]



Stock XLS, nothing aftermarket added. Never in accident. Hit fairly deep
pothole once is closest thing to collision. Four fairly new tires with air
pressure normal. Did have a flat tire (nail), but problem occurred after
that and after washing only.

I know this is a wild troubleshooting task. I also know this car's primary
(maybe only one) weakness has been the electrical system. I have been trying
to concentrate my efforts on finding out where moisture could affect either
of these components. Can anyone tell me exactly where the ABS sensor is
located? Exactly where does the EFI relay get it's input? That might help.

--
Message posted via [url]http://www.carkb.com[/url]

"erom43 via CarKB.com" <u27345@uwe> wrote in message
news:672a4a312513f@uwe...[color=blue]
> Ray O wrote:[color=green][color=darkred]
>>>>>>>A strange electrical problem has developed occasionally after washing
>>>>>>>or[/color]
>>[quoted text clipped - 33 lines][color=darkred]
>>> be
>>> appreciated. Thanks.[/color]
>>
>>I am not aware of any widespread problems like you are describing. By any
>>chance was the car ever in an accident? Are there any aftermarket
>>accessories installed like a remote starter, fog lights, satellite radio,
>>etc? If there is a yes to any of those questions, I'd start checking the
>>areas where the factory wiring was disturbed. If no, then all I can
>>suggest
>>is to try wiggling wires and wire looms when the problem occurs or take it
>>to a dealership for diagnosis.[/color]
>
>
>
> Stock XLS, nothing aftermarket added. Never in accident. Hit fairly deep
> pothole once is closest thing to collision. Four fairly new tires with
> air
> pressure normal. Did have a flat tire (nail), but problem occurred after
> that and after washing only.
>
> I know this is a wild troubleshooting task. I also know this car's
> primary
> (maybe only one) weakness has been the electrical system. I have been
> trying
> to concentrate my efforts on finding out where moisture could affect
> either
> of these components. Can anyone tell me exactly where the ABS sensor is
> located? Exactly where does the EFI relay get it's input? That might
> help.
>
> --
> Message posted via [url]http://www.carkb.com[/url]
>[/color]

There are 4 ABS sensors, one for each wheel. Each hub has teeth that look
like splines, and the sensor magnetically picks up the presence or absence
of the spline as the hub rotates, creating an on-off signal. The faster the
on-off signal, the faster the wheel is rotating, and if one wheel is
rotating at a different speed when the brakes are applied, the ABS system
kicks in. Look for a wire that snakes behind the brake backing plate, and
follow the wire to the ABS sensor.

A flashing ABS light is different from one that is constantly illuminated,
and I'd have to do some research to find out its significance.

The EFI relay probably gets its control voltage from the main computer.

You can get online access to the factory repair manual at
techinfo.toyota.com for $10/day.
--

Ray O
(correct punctuation to reply)