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Tables
- Altitude: these are to compensate certain functions based on barometric readings. if you think there is something that needs tweaking, these are probably not it.
- Shift light: simple enough: these tables determine when the shift light will come on based on RPM, gear and TPS%.
- Main Spark Advance: the amazing difference that can be had by changing spark is enormous. if you're picking up knock, you'll usually take it out of here or the TCC retard table. you MAY see an increase in power/economy by increasing advance, but it's a pretty hit and miss thing since it depends on a LOT of factors.
- PE Spark Adder: I don't like this table. it adds spark based on your AFR in PE. you normally won't need more spark in PE to make best power.
- Idle spark retard/advance due to over/underspeed: yep.... exactly how it sounds. the ECM will slightly retard or add more advance due to the engine not hitting target idle speeds.
- Base Coolant Spark Advance: this table exists to take advantage of the fact that at lower coolant temps, you can run more advance safely. you can also retard spark at higher coolant temps to help reduce the occurrence of knock
- EGR Spark Advance vs %EGR: if your EGR was disabled, and you weren't picking up knock until you re-enabled it, this is probably your culprit.
- Knock attack/recovery rates: its how quickly the ECM will remove and then add back in the commanded spark when it detects knock.
- Max knock retard: exactly as it sounds, it's the maximum amount of advance the ECM will pull when it detects knock.
- TCC Locked Spark Retard: the ECM retards spark just because the TCC is locked. you MAY see a benefit here by reducing the amount of retard, but should be played with only after the main spark table is refined.
- Idle spark multiplier vs coolant temp: table based on coolant temp to change the amount of advance delivered to keep the engine happy.
- Initial timeout spark: this is the amount of (additional) advance the ECM will command during cranking after the ICM does its job.
- Spark timeout decay: how quickly the ECM removes the added spark for initial advance to go normal.
- Idle spark multiplier vs MAP: same idea as the vs coolant temp.
- Launch mode spark advance: here is where the basis of the launch mode advance is drawn from.
- Stall torque management: these determine how the ECM commands advance when the converter is being stalled. I'm not quite sure how the * of advance plays in, but I've never had to mess with it either. it feels like a torque management type of table.
- CCP: this is how CCP duty cycle is derived. increasing it can do a few good things for you: better fuel economy, less pressure in the gas tank, decreased emissions from a pressurized tank. it could also throw your fuel tuning off, so disable it in the constants until you are done with EVERYTHING else, including EGR tuning.
- TCC: the load limits allow you to determine when the TCC will be unlocked when you either have too much or not enough throttle for it to be intelligent for it to be engaged. the load limit doesn't seem to correlate perfectly with TPS%, so it will be a matter of feel and memory to get this perfect.
- Converter stuff: it's how the ECU calcs exhaust temps and what to do if they reach the overtemp threshold... either the added advance or added fuel table seems to disable highway fuel if they are cleared out.
- Fuel multiplier vs map/baro: this delivers varying amounts of fuel based on the barometric to MAP ratio. possibly to compensate that shooting into a vacuum compared to a non-vacuum will result in different fuel flows...
- Base Pulse Constant vs Desired EGR: does more than you think. in the 0% position, it's actually a comparison of injector flow to engine size. make baby steps in your calculations if you have to change it. too much change can throw an otherwise good tune WAY off. a 10% increase in engine size will require a 10% increase in all cells, unless you have EGR permanently disabled, in which case, just adjust cell 0. a 10% increase in injector flow requires a 10% reduction of all numbers (unless EGR is not going to be run).
- Main/idle/base VE: already been discussed.
- VE modifier when EGR On: doesn't seem to be used with the 4t60 cars, but its hit and miss otherwise. may be due to other car lines using a different type of EGR.
- Open loop idle AFR multiplier: varies idle AFR in open loop based on MAP.
- Open Loop AFR: you can bump economy up quite a bit by leaning out certain sections of these tables, just don't go too far and cause stalling/surging issues.
- Open loop closed throttle AFR: sets the target AFR while in open loop idle. the MAP based multiplier is in play here.
- BLM Delay vs Delta between INT and 128: this can essentially be used to have an autotuning car, since you change how quickly the BLM reacts to INT change. it's not very safe to do this, but also has other uses.
- Injector offset vs battery voltage: this is how the ECM accounts for changes in battery voltage, which changes how quickly the injectors pop open.
- Injector offset vs base pulse width: this table adds more pulse width time to the BPW to account for very short opening times not actually opening the injector for as long as intended.
- Cranking Fuel: exactly as it sounds. factory numbers are probably quite rich, but I don't know, I don't have starting issues.
- Choke Fuel: exactly as it functioned on a carb: changes the AFR for a specified amount of time by a specific amount after a specific delay and then decays by a specific amount until it hits the desired AFR in open or closed loop, depending on start-up temp and the time it spends in choke. confusing enough? Again, factory feels quite rich, especially for MPFI systems...
- PE AFR: look how rich it is (see the pattern yet?)! there is power to be had by leaning it out, believe it or not. I like 12.5:1 everywhere; it's rich, but safe.
- AE: acceleration enrichment: is used during throttle transitions to add extra fuel (just like a pump shot on a carb). if you have a stumble when stepping on the throttle, this is probably why. if it only happens at certain coolant temps, elevations, or air temps change the appropriate table. if it's something constant across those variables, it could be either of the two remaining tables, but AE Enrich vs AE Pulse is the easier and safer one to play with.
- DE: this is how you adjust the severity, length and the conditions in which DE will happen.
- TPS needed for PE: this is where you set the throttle threshold to allow PE fuel and spark. I would never want it beyond 50%.
- O2 reference upper/lower: this is what the ECM is targeting when it's averaging an AFR. going beyond the rich table will cause the INT to move to allow for leaner fueling, while going leaner will cause the INT to move toward the rich side. there are offsets based on coolant temps, which is why you should never make fueling based adjustments until you're at full operating temp, or you minimize the effects here.
- INT Delay: how long the INT waits after the O2 sees a fueling error before moving based on engine airflow. stock tables aren't bad, but have room for improvement.
- Base pulse inverse IAT vs IAT: IDK WTF this table is for, since all it seems to do is correlate degrees Kelvin and degrees Fahrenheit...
- Desired idle speed: I think some of the lower temps RPMs are a bit high, but this is a preference/need based table, so stretch to fit.
- Throttle follower decay rate: ever let off the throttle and the engine's RPMs seemed to hover and then drop? this is why. you can speed it up or slow it down, but it affects drivability quite a bit.
- IAC warm park position: this is more or less what the ECM is expecting to add to the IAC to be at a stable idle based on various coolant temps.
- Max throttle follower steps vs vehicle speed: throttle follower is to help maintain a smoother operation of the engine. too many steps and it can seem like just a small amount of throttle change vastly changes the target vehicle speed. change here if necessary.
- IAC motor step offset vs temp: if you only seem to have an overrun idle at certain starting temps, this is the place to fix it.
- Over/underspeed proportion feedback: this is to give the ECM some kind of idea how far to move the IAC to keep the idle correct. shouldn't need to play with.
- Speed increasing/decreasing derivative feedback: similar idea as above, but this basically takes place when already in action.
- Integral gain rates vs pos/neg error: also similar to the above, and shouldn't be messed with.
- Warm parkdown bias vs baro: compensating altitude to the number of added steps to the IAC.
- EGR: 5 tables here, the solenoid combination controls which of the 3 solenoids is allowed to be opened for EGR. flow approximates the amount of EGR flow that is pushed into the motor based on solenoid combination. duty cycle multiplier speaks for itself, VE compensation when TCC locked is another way of saying that based on backpressure, this much spent exhaust gas is going into the engine and EGR desired advance lag filter vs airflow shows how the ECM will "slowly" add advance when the EGR solenoids are opened.
Something i've discovered recently: in the A1 mask at least, idle is more or less Alpha-N(comparing throttle position and RPM to determine fueling) if the "Idle Fuel" Flag is set. this is how it works:
- Airflow offset for %TPS vs RPM: This is the basic table used for the Alpha-N equation. The ECM grabs the value here and uses the next tables to manipulate it and to get a more accurate value. Every TPS% point will add the amount of grams/sec to the equation as shown in the table, with the ECM interpolating as necessary.
- Airflow multiplier vs map/baro ratio: This is used to add to or subtract from the initial value based the ratio of MAP kPa to barometric kPa
- Airflow multiplier vs MAT: This table is then used to add or subtract from the calculated values to compensate for the fact that colder air is denser and has more oxygen in it.
- Airflow multiplier vs baro: lower barometric pressures mean less air being pushed in via atmosperic pressure, this table accounts for that.
- Airflow vs IAC Motor Position: next, the calculated value is offset by the amount of steps as shown in this table.
- Airflow vs IAC Minimum Motor Position: Finally, this table is called upon for a final offset, and the stored value is then used in combination with the constant that describes fuel flow in seconds per gram to determine pulsewidth.