Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com - View Single Post

RH77 · 02-25-2009, 01:15 AM

I have a '98 Integra and understand your question. The Honda 4-speed automatic has 3 lockup positions: partial, half, and full. If you select D3 on the shifter, it will not engage the torque converter -- otherwise, the TC can engage in 3rd or 4th gear in D4.

So how to know? The easiest way to know, is to watch for a small drop in RPM. Full lockup is about a 500 RPM drop, with the other two slightly less.

Lifting the gas pedal and re-applying the throttle will definitely tell you if you're in lockup. If the engine RPM goes up with no drop, it's not engaging. If it slips down a bit -- you're engaging.

Personally, I have a quite the issue with TC engagement. Coolant temp is a big factor. The Honda Transmission Control Unit (TCU) is the "End-All Be-All" in transmission decisions. If you engine-off coast, then it confuses the hill-logic control circuit, and will not engage the TC until the calcs satisfy a condition of higher-speed cruise. It uses engine load, speed, acceleration, deceleration, and throttle position to determine if a your going up or down a hill.

Long story short, gaining access to a shop manual will help tremendously.

Best FE to you...

RH77

02-25-2009, 01:15 AM	#7 (permalink)
RH77 Depends on the Day Join Date: Nov 2007 Location: Kansas City Area Posts: 1,761 Teggy - '98 Acura Integra LS Sports Cars 90 day: 32.74 mpg (US) IMA - '10 Honda Insight EX Team Honda 90 day: 34.76 mpg (US) Tessie - '06 Acura TSX Base 90 day: 28.2 mpg (US) Thanks: 31 Thanked 41 Times in 35 Posts	I have a '98 Integra and understand your question. The Honda 4-speed automatic has 3 lockup positions: partial, half, and full. If you select D3 on the shifter, it will not engage the torque converter -- otherwise, the TC can engage in 3rd or 4th gear in D4. So how to know? The easiest way to know, is to watch for a small drop in RPM. Full lockup is about a 500 RPM drop, with the other two slightly less. Lifting the gas pedal and re-applying the throttle will definitely tell you if you're in lockup. If the engine RPM goes up with no drop, it's not engaging. If it slips down a bit -- you're engaging. Personally, I have a quite the issue with TC engagement. Coolant temp is a big factor. The Honda Transmission Control Unit (TCU) is the "End-All Be-All" in transmission decisions. If you engine-off coast, then it confuses the hill-logic control circuit, and will not engage the TC until the calcs satisfy a condition of higher-speed cruise. It uses engine load, speed, acceleration, deceleration, and throttle position to determine if a your going up or down a hill. Long story short, gaining access to a shop manual will help tremendously. Best FE to you... RH77 __________________ *“If we knew what we were doing, it wouldn't be called research” ― Albert Einstein* _ _