Set Condition
- Set Condition for Signal Invalid or Missing:
The failure is detected if at least one of the following malfunctions is verified:
1) CRC and Message Counter Check: A signal toggle bit and a signal parity bit are sent by the PCM within the CAN message. In order to be sure the message content is continuously updated, the value of the toggle bit changes from 0 to 1 and vice versa every two messages. In order to be sure the message is valid, the parity bit value is set so that the sum of the signal bits (ENG_RPM) of the message content plus the toggle bit plus the parity bit is an even number. If the toggle bit value does not change for a calibrated amount of time or the signal parity is not verified then DTC U11D1 is set.
2) Signal Not Available Check: When the signal is not available, the PCM sends an SNA default value to the TCM. If the TCM reads this value then DTC U11D1 is set.
- Set Condition for Signal not Rational - Engine Speed Check for Zero Value
The failure is detected if the received engine speed value is equal to 0 RPM then DTC U11D1 is set.
- Set Condition for Signal not Rational - Engine Speed Compared to Odd or Even Clutch Speed and Odd or Even Input Shaft Speed
The failure is detected if the difference between the received engine speed and the odd or even clutch speed is greater than 500 RPM and if the difference between the received engine speed and the odd or even input shaft speed is greater than 500 RPM then DTC U11D1 is set.