91 Es250- Still Struggling With Code 52-knock Sensor

[jjewell]

I've gone over the whole circuit for/including the sensor-reset ecu-chem treated fuel system-keep getting the knock sensor code! :cries: Been searching threads for days- no real solutions. Saw one thread suggesting a resistor to simulate sensor signal to ecu. Anyone done this? What value of resistor?

I gotta get this car smogged- running out of time! Please, can anyone give me some help? :( I've also gone over the fsm- still no good. My fingers be very sore for the searches. OR...........

would I be better off getting another knock sensor, locating it elsewhere (where it's easier to get at) & wiring it in? is it position sensitive?

This car runs great, even with the code. But it sure is wearing me down!

[bob95603]

I'd disconnect the battery (appears that you may have done this) to reset all the codes. Leave it disconnected for about 2 minutes to ensure everything is wiped out. Reconnect and see if you still get the code.

Take the car on the freeway for about 20 minutes and then get a smog pre-check (about $35) to see if it will pass. If it doesn't pass, go to DMV and see if you can get an extension. Tell them the part is on order but delivery is in about 10 days. I just got an extension this AM for a brake and light inspection. Get there about 10 minutes before they open and you'll be in and out in about 10 minutes (vs the normal 3 hrs around here).

Where are you in N Calif? I'm in Auburn and have a 1990 FSM but couldn't find anything in there regarding a knock sensor code.

[jjewell]

I'd disconnect the battery (appears that you may have done this) to reset all the codes. Leave it disconnected for about 2 minutes to ensure everything is wiped out. Reconnect and see if you still get the code.

Take the car on the freeway for about 20 minutes and then get a smog pre-check (about $35) to see if it will pass. If it doesn't pass, go to DMV and see if you can get an extension. Tell them the part is on order but delivery is in about 10 days. I just got an extension this AM for a brake and light inspection. Get there about 10 minutes before they open and you'll be in and out in about 10 minutes (vs the normal 3 hrs around here).

Where are you in N Calif? I'm in Auburn and have a 1990 FSM but couldn't find anything in there regarding a knock sensor code.

I'm in Concord, west of SF. Yeah, I've done the battery thing, etc. This AM I got some electrical contact cleaner spray & doused the male & female connectors, dried them & put in some dialectric grease before reassembly. Drove around doing errands (freeway & town) 20 miles- so far knock wood, no code. The code 52 says basically no communication between ECU & sensor. The cel has been intermittent at times- no other codes. Hoping the clean connection does the trick.

I have the 91 FSM in full & it goes into the codes quite a bit in detail. Gonna do some things around the house then take her out on the road again. Keep yer fingers crossed for me!

[bob95603]

Where's that sensor located?

[jjewell]

Where's that sensor located?

Under the intake manifold. :cries: Sure hope I don't have to replace it! Entails about 4 careful hrs. of work. I've checked several threads on it to help "semi" prepare myself if it comes to it.

[ArmyofOne]

Where's that sensor located?

Under the intake manifold.:cries: Sure hope I don't have to replace it! Entails about 4 careful hrs. of work. I've checked several threads on it to help "semi" prepare myself if it comes to it.

I told you, if it comes down to it, pull the cluster out and yank the bulb out. get it smogged, then fix the problem and stick the bulb back in. It will pass even with that sensor out.

Edited December 29, 2005 by ArmyofOne

[jjewell]

Where's that sensor located?

Under the intake manifold.:cries: Sure hope I don't have to replace it! Entails about 4 careful hrs. of work. I've checked several threads on it to help "semi" prepare myself if it comes to it.

I told you, if it comes down to it, pull the cluster out and yank the bulb out. get it smogged, then fix the problem and stick the bulb back in. It will pass even with that sensor out.

Thats good news it will pass. I'm just being anal about the prob. Just trying to get it fixed as least painfully as possible.