Got an ongoing issue with my car and I am somewhat lost on working out what the issue is.
Car comes up with an EFI 52 error. According to the diagnostic chart, that error is for Knock Sensor (the one located in the engine on the passenger side of the car). Once the error appears, that car goes into "limp home" mode.
From what I can tell, there is no knock occurring at all.
The error will come up when the car revs to about 2000 rpm or so, and only when the engine is warm. It does not happen when the car is cold. Once the car is warm, I can reproduce the EFI 52 error consistently.
I replaced both the oxygen sensors thinking they might be somewhat responsible, but that hasn't helped either. Not that it hurt as the car still had the factory sensors.
I tried the fuel pump bypass trick to see if the engine was getting starved of fuel and hence triggering the knock sensor, but that didn't help.
So far, I have replaced the knock sensor in question, but that hasn't helped. I was at, one stage, getting EFI 42, which is the Air Flow Meter. That got replaced and went away but funnily enough, EFI 52 has remained.
I have also had the ECU out of the car and had a look. Can't see anything that resembles leaking capacitors, at least not in my eyes. Happy to take it out again and take some photo to see if anyone else can see an issue.
Not sure where to proceed from here. Any ideas what the issue might be?
Sunday, July 29, 2012 - 09:45 pm, by: Katsuji Ueda(Senrioka8)
EFI error code 52 is fault with knock sensor signal system. Diagnostic condition: The error code will appear when knock sensor or wire-harness is open or short when the engine rev. will be between 1600rpm~5200rpm. Check points. 1: Wire-harness and connector (Knock sensor system) 2: Knock sensor ( left bank ) 3: Engine control computer
Tuesday, July 31, 2012 - 08:47 am, by: Damian Ware(Frozenpod)
I have never seen the error code for the AFM be correct yet.
Every instants of the AFM error code I have seen has been caused by a faulty ECU.
Assuming that your AFM was faulty and you have already replaced the sensor I can only suggest checking the wiring very closely.
The knock sensors have a shielded wire and if the shielding is damaged they pick up noise which upsets the ECU. 1uz's seem to produce the most noise at around 2000-2400rpm it could be the cause.
Alternatively given your AFM error code the knock sensor may be fine but your ECU could be the problem.
Damian, I too was surprised that about the AFM error, and even more surprised that replacing the AFM didn't fix the EFI 52 error along with it. When you say to check the wiring, do you mean the wiring on the AFM or the Knock Sensor wiring?
So, I got around to taking out the ECU this morning, and I came across one capacitor that was leaking from the the bottom. It's only a small amount, which is probably why I never saw it before.
Once I saw some muck under the capacitor, I got out a toothpick to see if it was solid or not, and it was just fluid and that pretty much sums it up. It appears to be in the early stages of leaking.
Saturday, September 15, 2012 - 07:47 pm, by: Anthony El-Khoury(Mushu)
So, just another update and further twist.
ECU have been sorted out, thanks go to Damian for this.
However, the issues still remain.
Have yet to take the Knock Sensor out to test for continuity as it was a pain to get it out last time and I really don't want to do it again, but it looks like that might have to be the next step.
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