A4 Engine Braking

[neil]

Can the PCM be programmed for automatic down-changes for engine braking on deceleration?

Regards,

Neil.

[emarkay]

Wouldn't a manually selected downshift be more versatile?

[joecar]

Neil,

Engine braking is only available when the Overrun Clutch is applied (1st gear also requires the Lo/Rev Clutch to be applied);

In the chart, if you look down the column "Overrun Clutch" you'll see that it is not applied for the following:
- 1st, 2nd, 3rd, 4th gears in Manual 4 range ("OD");
- 1st, 2nd gears in Manual 3 range;

So in either of these ranges (OD or 3), an automatic downshift to a lower gear will not give engine braking...

The chart shows that a manual downshift is required, and as MRK said this would be more versatile...

Also, if you programmed the PT upshift/downshift curves to attempt this, you would be "holding" each gear at part throttle, causing fuel consumption to increase (as would gear wear), and driveability would feel all wrong.

Joe


http://img176.imageshack.us/img176/9550/4l60erangechartmt9.png