Code 52...

[CajunKenny]

I just fixed my code 51 just the other day and now a code 52! When will the madness stop!?!?!?!??

I'm not convinced I have a bad Knock Sensor. I have a suspicion that it's linked to my recent Speed Density Conversion. It's just a suspicion though...

My check engine light came on Sunday Night while headed to a resturaunt. I did not have a paper clip on me to pull the code and when I came out and started it up to head home, no check engine light.

My questions:

The car still has this hesitation/miss at constant throttle. Will a code 52 cause this? Is it causing timing to be all over the place hence causing the constant throttle shutter/miss?

Does the fact that the car acts this way at constant throttle, indicate for sure that it's the knock sensor?

Thanks!

 

[boosted2085]

51 usually causes that..are you running part throttle and full throttle?..also are you in open or closed loop?..possiblity that the ecu could be fighting the maftpro over the correction

 

[CajunKenny]

Code 51 can/will cause Code 52? Or do you mean that 51 will cause the hesitation?

It seems to only happen in closed loop.

After getting my TPS adjusted back into spec, 51 cleared itself. It never returned.

I am not using Part Throttle Tracking.

I am using AFR Tracking. Currently, my tune is conservative. 11.1-11.3 afr @ ~14psi.

 

[CajunKenny]

Where in the TSRM is the Knock Sensor Information?

Link?

Anyone...??...Anyone...??...Beuller...??...Beuller...??... :biglaugh:

 

[ben1984j]

I just fixed my code 51 just the other day and now a code 52! When will the madness stop!?!?!?!??

I'm not convinced I have a bad Knock Sensor. I have a suspicion that it's linked to my recent Speed Density Conversion. It's just a suspicion though...

My check engine light came on Sunday Night while headed to a resturaunt. I did not have a paper clip on me to pull the code and when I came out and started it up to head home, no check engine light.

My questions:

The car still has this hesitation/miss at constant throttle. Will a code 52 cause this? Is it causing timing to be all over the place hence causing the constant throttle shutter/miss?

Does the fact that the car acts this way at constant throttle, indicate for sure that it's the knock sensor?

Thanks!

The code 52 couldn't be causing the hesitation/miss...it doesn't cause timing to be "all over the place" it just retards timing, also makes you run pig rich. The knock sensor might be fine, it's more likely the wiring that's at fault, but I would count on it being one of the two...

The only noticeable effect of a code 52 as far as I know is a loss of power and fuel economy...no effect on how the car runs...so I don't think there's any way it is related to your problem.

 

[shaeff]

A hard enough knock will cause the engine to hesitate on the cruise or cause sudden reduction in power during acceleration. Resuming previous operation makes it hard to pinpoint the cause.
Ironically enough, knock sensors can detect engine knock caused both by detonation/pre-ignition and rod knock. Lets hope its not option 2.

NO! Rodknock has absolutely NOTHING to do with code 52, EVER! The knock sensor's job is to look for a specific frequency at which spark knock occurs, in this case, 7kHz is the magic number where max timing is pulled. When the ECU gets this signal from the knock sensor(s), it will retard the timing and enrich fuel mixture.

Again, RODKNOCK HAS NOTHING TO DO WITH CODE 52, EVER!

Code 52 dictates that you have an electrical problem ONLY, and it's limited to the knock sensor circuit.
1) Bad wiring
2) Bad knock sensor(s)
3) Bad ECU (It's rarely ever this option- I've never seen a burned out 7M ECU)

http://www.supramania.com/forums/showpost.php?p=1315799&postcount=7

http://www.supramania.com/forums/showthread.php?t=107129&highlight=7khz

 

[CajunKenny]

Where in the TSRM is the Knock Sensor Information?

Link?

Anyone...??...Anyone...??...Beuller...??...Beuller...??... :biglaugh:

 

[shaeff]

I would link you to it, but I'm on my work PC and the TSRM is blocked.

 

[CajunKenny]

Ah. Last night I went through the EFI and Ignition Sections without any luck. I must have missed it...

 

[boosted2085]

i looked on the tsrm but when i went to the diagnosis page it tells you what page you can find whats the issue about that item but code 52 and 53 had no available page...im sure someone will have it though

 

[CajunKenny]

I hope so because I have immediate access to another one.

I'd like to at least know where they're located so I can replace it.

 

[CajunKenny]

I just found the Knock Sensor Rewire thread. Is this the "Fix" to code 52 or do I possibly just have a bad sensor?

I would hate to do all that work when I can just replace a sensor.

 

[ben1984j]

I hope so because I have immediate access to another one.

I'd like to at least know where they're located so I can replace it.

The knock sensors are on the driver's side of the block. They have green plugs going into them, can't miss 'em. The front knock sensor can be easily accessed by removing the alternator, and to get at the rear sensor you have to remove the starter.

I just found the Knock Sensor Rewire thread. Is this the "Fix" to code 52 or do I possibly just have a bad sensor?

I would hate to do all that work when I can just replace a sensor.

It's usually the wiring though...plus even if it's one of the sensors you don't know which one. It's good to do the re-wire before you start replacing sensors, because most of the time that fixes the problem.

 

[CajunKenny]

I'll take that as sound advice.

It looks like I have some weekend work then!

 

[shaeff]

The knock sensors are on the driver's side of the block. They have green plugs going into them, can't miss 'em. The front knock sensor can be easily accessed by removing the alternator, and to get at the rear sensor you have to remove the starter.

It's usually the wiring though...plus even if it's one of the sensors you don't know which one. It's good to do the re-wire before you start replacing sensors, because most of the time that fixes the problem.

This is good advice, however on '89+ cars, the rear knock sensor location moved a bit forward (toward the front of the car) and as such, with care, the rear KS can be removed without touching the starter. I still recommend disconnecting the battery though, as the + battery cable is right there, and if you hit it, well.... zap!

I'll take that as sound advice.

It looks like I have some weekend work then!

There's a great tutorial here in our Articles section:
http://www.supramania.com/forums/showthread.php?t=105505

 

[CajunKenny]

Thanks for the tip on regarding the rear ks shaeff.

A big thanks to everyone else too. My hats off to y'all!

One last question: I've seen a couple different KS part numbers floating around. One from Toyota and one from Champion. Is one better than the other?

 

[CajunKenny]

I thought of something regarding the re-wire writeup.

Why would I need to order new connectors? If that part of the harness is bad and the old ones would just get unplugged and left hanging there, why couldn't I just cut off and use the original connectors?

I suppose the original ones could be brittle; but, other than that, the old ones should work. Right?

 

[shaeff]

I thought of something regarding the re-wire writeup.

Why would I need to order new connectors? If that part of the harness is bad and the old ones would just get unplugged and left hanging there, why couldn't I just cut off and use the original connectors?

I suppose the original ones could be brittle; but, other than that, the old ones should work. Right?

Because they're only about $7 each and then you're working with all brand new materials that are squeaky clean, and connect fully and properly. Also make sure the o-rings on the KS's are in good shape.

 

[CajunKenny]

O'Rings!? Good call! I'll replace them too. I didn't know the KS's had O'Rings on them.

Can you tell I haven't had to do any KS work yet?

 

[Igknyte]

i used Shaeffs rewire kit and no more check engine light for code 52.
worked great.
Thanks again Chris.

but here is a pic of where teh knock sensors are located.
i was able to get to both ks without removing anything just disconnecting some cables connected to the battery and around the battery and alternator.

but my arm came out black when i was done.

onto my brakes..!