19.0 TCC Lockup Parameters

19.1 Overview

The ECU can control a torque converter clutch (TCC) in an automatic transmission.  The TCC output (ECU pin B6) is switched to ground when the ECU determines the TCC should be locked.  The ECU will lock the TCC when %TPS and vehicle speed meet user-defined thresholds.  To get vehicle mile per hour, your vehicle must be equipped with a vehicle speed sensor (VSS).  That VSS will need to be calibrated to your ECU using the Rate Sensor Calibration found below in this section.

19.2 Min %TPS for TCC Lock

This parameter sets the minimum %TPS required for TCC lockup.  It is used to prevent TCC lockup during closed throttle coast down.  By unlocking the TCC, the engine is allowed to rev lower to conserve fuel.  This would normally be set between the “TPS %” readings at idle and cruise.  It needs to be set lower than the “Max %TPS for TCC Lock” setting. 

19.3 Max %TPS for TCC Lock

This parameter sets the maximum allowed %TPS for TCC lockup.  It is used to prevent TCC lockup during heavy acceleration.  An unlocked TCC will prevent wear and allow the benefits of torque multiplication to be realized.  This would normally be set between the “TPS %” readings at cruise and at WOT.  It needs to be set higher than the “Min %TPS for TCC Lock” setting.

19.4 Min. MPH for TCC Lock

This parameter sets the minimum vehicle speed required for TCC lockup.  This setting is used to prevent TCC lockup at low speeds, which could lead to stalling.

19.5 TCC Lock Delay (s)

This parameter sets the length of time the %TPS and vehicle speed enable conditions must be met before the TCC will lock – or conversely, the length of time the enable conditions must be unmet before the TCC will unlock.  This feature prevents repeated locking and unlocking when %TPS or MPH is right at one of the enable thresholds.

19.6 Rate Sensor Calibration

The ECU has provisions for a drive shaft speed input.  This speed can be monitored with the “DS RPM” channel.  This input is also used to calculate vehicle speed - which is used in various speed related calculations and controls.  For example, vehicle speed is an enable condition for torque converter lockup.  It is also used to calculate fuel mileage.  Vehicle speed can be monitored with the “MPH” channel.  Fuel Mileage can be monitored with the “MPG” channel.

The ECU also has provisions for an additional rate sensor.  This rate can be monitored with the “AUX RPM” channel.

The ECU will accept either discrete/Hall Effect or inductive type signals as its speed inputs.  There is a separate ECU pin for each type.  The following pins are found in the VSS connector on the main harness:

                                    Pin C – MPH Inductive, yellow

                                    Pin B – MPH Discrete, white

The following pins are found in the SHAFT connector on the main harness:

                                    Pin D – Shaft Inductive, purple

                                    Pin B – AUX Discrete, orange

NOTE - Whichever inputs are not being used should be connected to ground.  This will prevent the unused inputs from floating and falsely triggering the ECU. 

19.6.1 Driveshaft RPM Calib. (600/PPR)

Divide 600 by the number of pulses per revolution of the drive shaft and enter the result here. 

19.6.2 MPH Calibration

To calculate this number, multiply your tire diameter (in inches) by 195.  Then divide the result by your final drive gear ratio.

MPH Calibration = (195 * tire diameter) / gear ratio.

For example, if your tire diameter is 26 inches, and your final drive gear ratio is 3.42:1, the MPH Calibration number would be 1482.

MPH Calibration = (195 * 26) / 3.42 = 1482.

19.6.3 Aux. RPM Calib. (1200/PPR)

Divide 1200 by the number of pulses per revolution of the part being measured and enter the result here.