ECMlink [RESOLVED] 2G Stuck in open loop among other issues

[Dryppical]

I have a 1997 Eclipse GSX and I have been driving it for 800 miles since my manual swap. Didn't have any issues with it until last week the alternator went out. I got a new one and put it in along with a 3" aluminum intake and throttle body shaft seals. I drove it into town and back with no issues.

Next day I went into town again and on my way back, my car had a stroke. The AFR gauge pegged rich, the car started bucking really hard and I pulled off into a parking lot and checked everything out. Nothing seemed wrong and I wasn't very far from home so I legged it home. I had to accelerate extremely slowly or else it would start bucking again.

The check engine light came on so I hooked up my laptop to check it out and I had a P0100. A mass air flow circuit malfunction. I then did a log so I can look at potential issues and I have all sorts of issues. I have no idea what I am looking at and I compared it to an old log I had of the car idling. The airflow no longer reads, the AFR stopped logging in DSMLink but my gauge still reads, it's stuck in open loop, MAF hertz no longer reads, airflow per rev no longer reads, mafraw reads 25hz when it should be reading 600 or so hz (I have a GM MAF with ECMLink adapter cable), combined fuel trim and selected LTFT don't read.

I figured my GM MAF maybe needed a cleaning so I cleaned it and same issue. I decided to try and replace it with a known good one and same issue. I have no clue where to start and everything was fine up to this point. The new log doesn't show the P0100 code as I cleared it after replacing the MAF and it didn't come back quite yet.

The "idle" log is from December 4th, 2024. Any help is greatly appreciated. My mods are up to date in my profile

 

[Dryppical]

I did a boost leak test. Had a boost leak before and after my MAF and at my T for boost gauge and afpr. Still no idea about my MAF or AFR being dumb in DSMLink. I assume it’s something to do with wiring. I have no idea. If any one else has any ideas, I’m willing to try whatever

I figured out why the ECU isn’t reading AFR. My wideband gauge isn’t sending a signal to the ECU. I tested right at the gauge and nothing. Maybe my gauge decided to half die on me?

 

[Dryppical]

Little update, I tried a known good afr gauge and same issue. I also tried a known good wideband o2 sensor and same issue. Something strange happened after I swapped the wideband o2 though. It came out of open loop for about 2.5 seconds and ran normal then went back into closed loop. For whatever reason something is causing it to be stuck in open loop. Now to find out why. Here's the log I took when it happened. It kicks into closed loop at 60 seconds and comes out at 62.5. Any input is appreciated

 

[steve]

Why is your Airflow and AirFlowPerRev = 0 for 99.9% of the time? (61 to 63 seconds in the log is the only time it worked). Either the GM MAF or the ECMTuning Adapter cable is acting up.

 

[Dryppical]

I figured that was a cause of open loop.

I did some testing for voltage on the GM MAF connector and it’s receiving 12V on the signal wire and to my understanding it’s supposed to receive 5v? I tested the stock MAF connector and I’m receiving 12v and 5v on the correct wires.

Looks like my ECMLink adapter cable must have died or something.

 

[steve]

Do you have a version 2 GM MAF Cable or one of the early ones? If it's a early version that doesn't have a separate ground wire you might try modding it. https://www.ecmtuning.com/wiki/gmmafcablemod

Also I'd guess you were failing the second and fifth tests which forced open loop.

2G Open loop mode (any one true)

Throttle position too high (varies by RPM)
Airflow too low (units are tricky, but it's very low)
Coolant temp < 51F
Coolant temp > 228F
The O2 sensor did not switch around 0.5v for over 128 seconds while running in closed loop mode. In that case, the ECU locks itself in open loop mode.

 

[Dryppical]

I have the v2 cable that has the separate ground. I’m going to try contacting ecmlink to see if they can repair it maybe?

 

[miliman13]

Little update, I tried a known good afr gauge and same issue. I also tried a known good wideband o2 sensor and same issue. Something strange happened after I swapped the wideband o2 though. It came out of open loop for about 2.5 seconds and ran normal then went back into closed loop. For whatever reason something is causing it to be stuck in open loop. Now to find out why. Here's the log I took when it happened. It kicks into closed loop at 60 seconds and comes out at 62.5. Any input is appreciated

It doesn't get hot enough and the throttle is active idk if you were doing this on purpose or not

As mentioned, you don't report a value for AirflowPerRev but looking at your load which usually is close to AFPR is very high. Engine has to be warm to really considerer any values.

Looking at the IDLE log form your first post

You must be logged in to view this image or video.

You do appear to go into closed loop again not very warm

in the 2nd log you show no value for AFPR or load
for all 3 logs your ISC position seems high.

Someone correct me if I am wrong, but AFPR or Mass Air Flow M_dot is a function of the MAS or MAP sensor depending on set up.

 

[Dryppical]

I found out my ECMLink GM MAF cable was bad. The circuit board died on me. I bought another ECMLink cable and put it in and problem solved. Thanks everyone for the help!