Attention: TDR Forum Junkies 
Would someone with a new '08 Ram tell me how the exhaust brake is factory programmed to operate?
My '06 with OEM Jacobs Exhaust Brake, 48RE, and 4. 10 gears is controlled by the ECM. When I lift my foot at highway speed the exhaust brake is activated and remains closed down to 40 mph. At 40 the exhaust brake opens momentarily, the ECM blips the rpm, the 48RE downshifts to 3rd direct, and the exhaust brake is again closed and remains closed down to 20 mph. At 20 mph the 48RE torque convertor unlocks and the exhaust brake is deactivated.
Today, just out of curiousity I drove an '08 Ram pickup with 68RFE and 4. 10 gears. At highway speed when I lifted my foot the exhaust brake engaged just like on my '06 but at around 40 mph the exhaust brake disengaged and remained off as the truck continued to slow. The transmission did not downshift as road speed declined whether in normal mode or "tow/haul mode. " I expected the exhaust brake to turn off momentarily while the transmission downshifted then close again and remain on down to 20 mph or so like my '06. I was surprised and frankly disappointed.
I've recently driven a couple of 4500 and 3500 cab and chassis trucks with the Aisin automatic. Each of those trucks activated the exhaust brake and kept it closed all the way down to 20 mph or less as it downshifted through the gears.
Was the operation of the Ram pickup I drove today out of the ordinary or is that the way they are programmed?
How about a cab and chassis owner? Does the ECM on the c & c trucks keep the exhaust brake engaged and downshift through the gears all the way down to 20 mph or below as I was thinking the trucks I drove did?
I'm confused by what I experienced today and now questioning what I thought I knew or understood about the new Rams.
Harvey
On edit: After posting this thread I had a thought that may answer my own question. Before I slowed the first time and observed the exhaust brake operation described above I had been experimenting with the thumb shifter. I shifted down a couple of gears then back up to sixth. I didn't know at the time but after shifting back up to 6th gear it is apparently necessary to flip the thumb shifter one more time to return the transmission to full automatic operation. I didn't notice until later in the test drive that "6" was displayed in the instrument panel. I realized then that I had locked it in 6th gear and had not returned the transmission to computer control. I think that may have been the reason why the transmission did not downshift and did not keep the exhaust brake activated. I think I made a mistake but the computer knew better. I guess I was outsmarted by the computer.
My '06 with OEM Jacobs Exhaust Brake, 48RE, and 4. 10 gears is controlled by the ECM. When I lift my foot at highway speed the exhaust brake is activated and remains closed down to 40 mph. At 40 the exhaust brake opens momentarily, the ECM blips the rpm, the 48RE downshifts to 3rd direct, and the exhaust brake is again closed and remains closed down to 20 mph. At 20 mph the 48RE torque convertor unlocks and the exhaust brake is deactivated.
Today, just out of curiousity I drove an '08 Ram pickup with 68RFE and 4. 10 gears. At highway speed when I lifted my foot the exhaust brake engaged just like on my '06 but at around 40 mph the exhaust brake disengaged and remained off as the truck continued to slow. The transmission did not downshift as road speed declined whether in normal mode or "tow/haul mode. " I expected the exhaust brake to turn off momentarily while the transmission downshifted then close again and remain on down to 20 mph or so like my '06. I was surprised and frankly disappointed.
I've recently driven a couple of 4500 and 3500 cab and chassis trucks with the Aisin automatic. Each of those trucks activated the exhaust brake and kept it closed all the way down to 20 mph or less as it downshifted through the gears.
Was the operation of the Ram pickup I drove today out of the ordinary or is that the way they are programmed?
How about a cab and chassis owner? Does the ECM on the c & c trucks keep the exhaust brake engaged and downshift through the gears all the way down to 20 mph or below as I was thinking the trucks I drove did?
I'm confused by what I experienced today and now questioning what I thought I knew or understood about the new Rams.
Harvey
On edit: After posting this thread I had a thought that may answer my own question. Before I slowed the first time and observed the exhaust brake operation described above I had been experimenting with the thumb shifter. I shifted down a couple of gears then back up to sixth. I didn't know at the time but after shifting back up to 6th gear it is apparently necessary to flip the thumb shifter one more time to return the transmission to full automatic operation. I didn't notice until later in the test drive that "6" was displayed in the instrument panel. I realized then that I had locked it in 6th gear and had not returned the transmission to computer control. I think that may have been the reason why the transmission did not downshift and did not keep the exhaust brake activated. I think I made a mistake but the computer knew better. I guess I was outsmarted by the computer.
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