5 replies to this topic

[MDK87]

I'm hoping there might be a genius on here that might be able to shed light on a little problem I'm having with a stubborn GVR4. 
The car I'm working on atm is a PFL E39A with a single board conversion with a Moates emulator for tuning.

 

The ECU won't go into closed loop and as a result I am getting DTC 11. 
The TPS is set to 500mV in home position, the idle stop switch is set correctly and functioning (decel fuel cut is working). 
The narrowband sensor has been replaced with a new one.
Performed a boost leak test and rectified all of the leaks.
No detectable exhaust leaks pre-sensor.
The coolant temp sensor provides resistance values in line with the factory service manual for hot and cold.
With the car in open loop mode, idle is around 14.9 AFR, measuring the narrowband output with a DMM nets ~450mV so I don't think the sensor is a dud.

With this emulator I don't know how to log, so I can't check the barometer readings or IAT but the maf comp table hasn't been drastically changed.

ALL required for closed loop.

Coolant temp >= 190F
Intake air temp < 123F
Baro >= 22.9 inHg
Baro <= 31.6 inHg

ANY required for open loop.

Throttle position too high (varies by RPM)
Airflow too low (units are tricky, but it's very low)
Coolant temp < 87F
The O2 sensor did not switch around 0.5v for over 20 seconds while running in closed loop mode. In that case, the ECU locks itself in open loop mode.

The car idles and drives great apart from this, just want to get rid of the CEL. Any help is greatly appreciated!

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Edited by MDK87, 28 September 2015 - 12:06 AM.

[BMGTZ]

O2 sensor= fucked. Not getting hot enough to work. Try this,run the engine till warm. then bring revs up to 4000 and hold for about 30 seconds. chop throttle and allow to run down. you might see the 02 sensor start to cycle in your log.

 

 

I have had a similar issue with ecmlite. replaced with LC1 wideband...nothing else and problem gone as the O2 sensor is heated type

[MDK87]

I have the heater hooked up to ign power but I will give it a shot mate, thanks. 

[blackvr]

If you have altered MAF settings and injector scalings and light load mixtures ... the following can happen. The ECU wont go into closed loop if it is really lean ( or really rich ) at light load. Essentially, if it is really lean, it wont reach the trigger point of around 0.70 volts that trips it into closed loop. Likewise if it is really rich, the trigger point seems to be around 0.30V. at least that has been my observation when setting up new larger injectors with ECMTuning. It makes it very difficult to set up the latency values and Injector scaling when you cant log ... or check the data !!

[MDK87]

Oops, rookie error.

I'm using a Falcon sensor and I googled the pinouts instead of measuring them. I got the signal and GND reversed. This time I noticed the reverse polarity indicator on the DMM...
Now it is in closed loop and cycling. Took it for a 15min drive and no DTC's.  
Cheers for the help lads.

[blackvr]

Aah.... just remember that the two white wires are earth and power , polarity not important. Glad you have it sussed !