My EOBD Android App does seem able to see the Short and Long term trim values -- where as PISTON and Torque APPs do not. -- Car is totally bog standard 99 Modena ( but not for much longer ) -- Had a faulty O2 sensor (upstream B1) - changed both sides yesterday. Does anyone know the PIDs for all the interesting data... O2 sensor readings ? So i'm seeing in EOBD.... ................................ B1..................B2 Short.....................+24%..............-1.8% Long..........................0%..............-0.6% How does that compare to others ?
What kind of sample rate are you getting? I was trying using an ODB to check some ECU's readings on my challenge car but the ECU's were so primitive - bad sample rate, the data was useless. Thoughts?
I have all 3 types of interface BT / WiFi / USB BT seems the slowest. WiFi seems to update every seconds. USB updates every second. So WiFi seems ok. I just wish I had a PID table so I could get the actual O2 sensor values. After about 15mins of running i get a P0151 code on B2, telling me it can not see any activity on the O2 sensor.
In my opinion reading 02s in any fashion other than an O scope is pretty worthless. A proper 360 O2 signal is a near flatline at .5 or .6 volts. That series of Motronic reacts so quickly you do not get the big wave in the voltage pattern of prior systems.
Clearly i have something going on with Bank 2 (mistake in original post swap B1 and B2) P0154 = says no signal of O2 (B2 S1) but it takes a good 15mins for that code to appear. or a similar sort of code complaining about the O2 So that it runs rich. Are the O2 sensors wired directly to the ECU or do they go through some form of signal amp on the way ? I guess I can buzz the wiring from connector back to ECU connector, perhaps there is a broken wire/bad connector.
I have seen too many cases of no signal due to intermittent operation of an O2 sensor for me to spend much time trying to find it without first replacing the O2's. I have seen them just quit for a few seconds and set a light. If it has not been replaced, do so. Not sure what you mean. With no O2 signal it runs rich? If so something else is wrong. The car should run perfectly with the O2s disconnected. They are not required for proper running and if so they are compensating for another problem.
I did exactly that on Sunday night, replaced both S1 sensors with new. The lumpyness / misfire / hesitancy got worse today. Now here is the funny thing, this evening I.... a) unplugged the new o2 sensor (B2 S1) b) reset the ECUs (power off) to zero the trim offset And as of the 20min trip home car seems to be running smooth. But the EOBD software is saying that Bank 2 is running Open Loop where as Bank 1 is running Closed Loop. [ Just an update - the F1 issue was solved by changing the accumulator and a full bleed/relearn ]
Car should run perfectly with all O2s disconnected and is in fact a diagnostic procedure. O2s can hide problems or make bad problems worse. Lots of data cannot be read or read properly from both banks with generic equipment from the OBD port so I wouldn't spend much time trying to figure that one out. I have no idea what your F1 problem was but thanks.
+1 avoid the ECU via ODB that motronic is too slow, get 2 wideband O2s and pull data directly. AEM widebands will datalog for you at a decent sample rate. You should see 12.1-12.6AFR @ wide open. I do think as rifledriver mentioned that you have an issue. The ECUs should be in closed loop under 74% throttle and less then ??4000rpms?? don't really remember the rpm limit. Open loop is default in the event of O2's out of range, and as mentioned will run OK, bad fuel economy as the system can't lean out at part throttle.
Bank 2 is adding fuel, you are running lean. With 0% long term and 24% short term means it running open loop and you have a DTC causing the B2 to remain in open loop. Your standard OBD scan tool doesn't read all DTC's and there is a manufacter specific code causing the problem. Don't throw parts at it, take it to someone with a proper scan tool, read the DTC and then diagnose the issue.
Found a good garage called "Cavailo", Jack and Kelvin have been great, their boss has a 360 CS. Their Leonardo can talk to my TCU, but it actually crashes when it tries to talk to my ECUs. Which is why I asked on another thread whether the ECUs had gone through any software updates. Just waiting for another FChatter to pop into HK with his Leonardo to try that - see if we get the same result. Failing that I can go to the MDealer and see if I can have a scan on a SD2. Just to correct the info for AD170 when the O2 is plugged in, it's reports "closed loop" but the short an long trims both move toward +24% with it unplugged - it reports "open loop" (obviously) the ecu reports 0 for short and long. and the engine runs smooth. Observations... O2 plugged in 1. My Innovate O2 meter reports it was rich 2. Spark plugs are getting heavy carbon deposits O2 unplugged 1. Innovate say ok 2. Plugs (new) seem good. But agree need to hook up some diagnostic computer that can get all the fault codes.
Check for exhaust leaks, something is fooling the O2. Unplugged, the ECM reverts to pre- programmed fuel injector on-times.
I also get "Low Voltage on o2 Sensor" error. Does any one know; a) the pin out of the connector the O2 plugs into. b) Expected signals the typical output of the O2 (engine off) would be about 0.5-0.6volts ? (i have a scope) c) Operation of O2 - if supply voltage was low - would the output signal be lower than spec. Would a low output signal be telling the ECU that it was running lean and so the ECU added fuel. just a thought.
Unplug the other side and use a multimeter- on your good side, compare and check for a damaged wire. If I remember output is 0-5vdc, but look up the Bosch wideband their data sheet is good, don't use the Ferrari number use one from a Porsche- wideband from the same era. I'd check mine for you but away w family til Sunday. Low voltage will make the sensor read out of range and kick you into open loop. I think you just found the symptom, now what is causing the low v.
