93 V6 odd solution to CEL o-o

[Raptor5150]

so after alot of work i finally figured out whats been putting my car into safe mode...i replaced the knock sensors on both banks but i was still throwing a CEL and getting a code 55... i guess the wiring was melted or somthing on the right bank so it still wasent giving a signal...


very frustrating this safe mode is..but today i was driving with my AC on full blast on the body only setting..and normally when i drive for about 10 minutes ill throw a CEL but with the AC on...1 hour went by...no CEL o_O... just driving through town and stuff stopping and starting...and flooring it sometimes which normally makes me throw the CEL...


how does me having the AC on make my timing not retard to the maximum level (aka safe mode) ???

its soooo weird that this happened on 2 occasions its like a temporary fix untill i get new wires installed... im not complaining lol atleased i have the full power of my car when i want it...


any ideas?

[chronoti]

a/c idle up? it some how correcting another issue?

or you have a heat sensitive short where the ac is cooling the wire

[camry6]

Originally Posted by Raptor5150

so after alot of work i finally figured out whats been putting my car into safe mode...i replaced the knock sensors on both banks but i was still throwing a CEL and getting a code 55... i guess the wiring was melted or somthing on the right bank so it still wasent giving a signal...


very frustrating this safe mode is..but today i was driving with my AC on full blast on the body only setting..and normally when i drive for about 10 minutes ill throw a CEL but with the AC on...1 hour went by...no CEL o_O... just driving through town and stuff stopping and starting...and flooring it sometimes which normally makes me throw the CEL...


how does me having the AC on make my timing not retard to the maximum level (aka safe mode) ???

its soooo weird that this happened on 2 occasions its like a temporary fix untill i get new wires installed... im not complaining lol atleased i have the full power of my car when i want it...


any ideas?

Here's my opinion, take it for what it's worth......The problem doesn't lie with the knock sensors, as you have already found out, or the wiring leading to them. The ECU is overheating and giving you a false CEL. The computer is at fault and with your A/C set to max vent you are circulating enough cool air through the cabin, and the return air vent is underneath the dash, exactly the area where the ECU is located. This is supplying enough cooling to the ECU to keep it from throwing a CEL. Replace your ECU and it will be fine.

[Raptor5150]

Originally Posted by camry6

Here's my opinion, take it for what it's worth......The problem doesn't lie with the knock sensors, as you have already found out, or the wiring leading to them. The ECU is overheating and giving you a false CEL. The computer is at fault and with your A/C set to max vent you are circulating enough cool air through the cabin, and the return air vent is underneath the dash, exactly the area where the ECU is located. This is supplying enough cooling to the ECU to keep it from throwing a CEL. Replace your ECU and it will be fine.

awesome I will tell my dad I knew I had to replace it but noooo! they are all well it must be the wireing!


ill make sure he sees your post good sir ^_^ thanks so much camry6!

[camry6]

Originally Posted by Raptor5150

awesome I will tell my dad I knew I had to replace it but noooo! they are all well it must be the wireing!


ill make sure he sees your post good sir ^_^ thanks so much camry6!

It is not un-usual for these aging ECU's to not necessarily fail completely, but cause weird problems. Good luck! PS, the knock sensor wiring is very well protected from normal operation of the vehicle, unless it has been damaged during a recent repair, the wiring is likely O.K.

[Raptor5150]

Okay so new update...my dad just told me he wants to know where the ECU is located (not the thing under the passenger side seat right?) and he...uhh wants me to put an ice pack on it to make sure it's a heating problem and if it's not it could be a ground or somthing when the AC is turned on...I know your right but you know how it is convincing older people lol.. Also tell him how the return air vent is hitting the ecu and cooling it...

Thank you so much camry6 uve been a great help..just one more step to getting my camry going again lol..

[camry6]

Originally Posted by Raptor5150

Okay so new update...my dad just told me he wants to know where the ECU is located (not the thing under the passenger side seat right?) and he...uhh wants me to put an ice pack on it to make sure it's a heating problem and if it's not it could be a ground or somthing when the AC is turned on...I know your right but you know how it is convincing older people lol.. Also tell him how the return air vent is hitting the ecu and cooling it...

Thank you so much camry6 uve been a great help..just one more step to getting my camry going again lol..

The ECU is located underneath/behind the glove box on the passenger side. reach under the dash (above where the passengers feet are) under the glove box and pull down the plastic cover. Remove the screws and clips and nuts that secure the glove box into the dash and pull it out. Be careful of the wire that connects to the glove box interior light on the inside left. The ECU is mounted vertically on a holding bracket to the right. It is silver in color and has 3 or 4 large multi-pin harness connectors plugged into it. The return air duct is located underneath the dash on the passenger side. With the A/C on max, fairly cool air is being drawn back to the blower in that same area, it is likely cooling the ECU sufficiently to prevent it from malfunctioning. Good luck!