MAP Upper Voltage Error Limit

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JDD604
Posts: 3
Joined: Sat Jan 14, 2023 9:02 pm

MAP Upper Voltage Error Limit

Post by JDD604 »

I currently have an issue that may be related to the following:
http://www.ktuner.com/forums/viewtopic.php?f=42&t=2542

I am using the RSX KTunerPRB codebase. We have an RDX map sensor installed and calibrated in the settings (Scalar 600.00, Offset -200) and it seems to be reading correctly. However, we seem to be hitting the same limit as the other attached thread but only when closed loop is enabled.

The engine transitions to OL-Drive as expected in boost (with CL enabled) and remains there until just above 8psi. As we cross this pressure the engine will suddenly lean out. All the sensor values appear to be normal and flat with no obvious change other than the status changing to OL-WarmUp / CL. It does not seem to have a problem holding or exceeding 8psi on the dyno when closed loop is disabled though.

Is this a codebase problem, or do we have bin corruption?
KTuner
Site Admin
Posts: 3745
Joined: Mon Jul 22, 2013 8:13 pm

Re: MAP Upper Voltage Error Limit

Post by KTuner »

PRB has the limits raised already. The thread you're linking to was a TSX ECU that doesn't have the ability to enter MAP Sensor scalar information. The upper voltage error limit is at the top of the 5v range, around 4.98v. I doubt you're reaching that with just 8psi.

A corrupt bin won't run.
JDD604
Posts: 3
Joined: Sat Jan 14, 2023 9:02 pm

Re: MAP Upper Voltage Error Limit

Post by JDD604 »

After further review on the dyno yesterday, the problem may reflect this user's experience:
viewtopic.php?t=2451

We spent about 10 hours on the dyno tuning and troubleshooting this problem. We ended up leaving closed loop off for now since we couldn't get it to function as expected (only in boost).

The transitions from closed loop to open loop using either TPS or MAP based thresholds are not being respected. With closed loop enabled we found that modifying the "Closed Loop Lambda Target High Load" table had a dramatic effect in boost.

I changed the values from 80C to 1000C to 12.0 target AF and it richened up the AF ratio up to 10psi at WOT considerably. This is despite the fuel status claiming it was in OL-Drive. When I changed those values to 12.5 target AF (to test) the ratio went far too lean. These tables are having an impact to our ratios in boost even though they shouldn't be.
KTuner
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Posts: 3745
Joined: Mon Jul 22, 2013 8:13 pm

Re: MAP Upper Voltage Error Limit

Post by KTuner »

WOT Enrichment tables depict target a/f at WOT determination whether in CL or OL. That's based on your actual fuel maps being perfectly tuned for 14.7 fuel delivery.

You now linked to a thread about never going into open loop, but you said you're in OL - Drive. That's two unrelated threads you're trying to lump in.
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