Oh joy--a CEL
08-23-2006, 11:54 AM
#1
Weathergirl
Rennlist Member
Rennlist Member
Thread Starter
Oh joy--a CEL
The code is 1224. Came on twice--both times when I was in traffic inching forward at idle. I searched Rennlist and saw a thread that said this means intermittant oxygen sensor failure. I don't have the list of codes here at work. Is that correct for an OBD1 '95 993?
So, does this just mean replace the sensor? Or might there be some other problem that causes that code.
Thanks, - Jon
So, does this just mean replace the sensor? Or might there be some other problem that causes that code.
Thanks, - Jon
08-23-2006, 12:42 PM
#2
Rennlist Member
I had a differnt code, but pulled the connectors and doused them in electrical contact cleanner, reinserted them several times and after 700+ miles the fault has not returned.
That is a cheap way to go first. If that fails you might want to get an analysis done to determine if it really is the sensor or not a drive circuit. A common issue is the heater element falls out of tolerance.
That is a cheap way to go first. If that fails you might want to get an analysis done to determine if it really is the sensor or not a drive circuit. A common issue is the heater element falls out of tolerance.
08-23-2006, 04:10 PM
#4
Rennlist Member
Yes, if you look at the sensor it should have four wires (at least my 96 does). I think the two white wires are the heating element. Using a continuity meeter you can measure the resistance between the two white wires and it should be no more than 2.6 Ohms. If it gets higher than that the heater current will be too low and it can trip a fault.
I don't know what your fault number actually means, but I wouold start by cleaning the contacts of the O2 sensor connectors inside the engine bay. Then reset the CEL and drive it and see if it returns. If it does you need futher diagnostics to nail it down. Your fault code number might provide a clue, but I don't have a list of codes and their definitions.
If you look on the web and Google 'obd 1 1224 code' I found a link that describes the code for an OBD I fault with a BMW listed as "Intake Air Temperature Sensor".
I was thinking that the codes are pretty standard, but someone here may have superior knowledge.
So it may not be the O2 sensor.
I don't know what your fault number actually means, but I wouold start by cleaning the contacts of the O2 sensor connectors inside the engine bay. Then reset the CEL and drive it and see if it returns. If it does you need futher diagnostics to nail it down. Your fault code number might provide a clue, but I don't have a list of codes and their definitions.
If you look on the web and Google 'obd 1 1224 code' I found a link that describes the code for an OBD I fault with a BMW listed as "Intake Air Temperature Sensor".
I was thinking that the codes are pretty standard, but someone here may have superior knowledge.
So it may not be the O2 sensor.
08-23-2006, 05:14 PM
#7
Technical Guru
Rennlist Member
Rennlist Member
Fault code 24 is "Oxygen Sensor Short to Ground" and the first two digits "12" means intermittent failure so the problem could possibly be just the connector or the wiring to the sensor.
If the control unit detects an oxygen sensor voltage signal of more than 1.4 V or less than 0.1 V, the control unit switches to operation without oxygen sensor. (Short to ground or open circuit).
If regulation does not work and the sensor voltage is O.K., use System Tester 9288 to check the coding of the control unit before replacing it.
You can find the complete procedure for fault checking the O2 sensor HERE.
If the control unit detects an oxygen sensor voltage signal of more than 1.4 V or less than 0.1 V, the control unit switches to operation without oxygen sensor. (Short to ground or open circuit).
If regulation does not work and the sensor voltage is O.K., use System Tester 9288 to check the coding of the control unit before replacing it.
You can find the complete procedure for fault checking the O2 sensor HERE.
