U11D1, U11D4, and U0401 are PCM and TCM errors.
28 - DTC-Based Diagnostics / MODULE, Transmission Control (TCM), C635 DDCT / Diagnosis and Testing
U11D4-00-LOST PEDAL POSITION MESSAGE
Theory of Operation
This diagnostic checks the validity and availability of the gas pedal position signal which is sent by the Powertrain Control Module (PCM) via a CAN message. The diagnostic checks the validity by performing a CRC and message counter check to verify the gas pedal position signal is continuously updated by the PCM and that it has a valid value. The diagnostic also checks the availability by checking the received valid bit.
•When Monitored:
Ignition key is ON and the engine is not in cranking mode.
Power supply must be between 7 volts and 24 volts and the Main Micro Processor (MMP) supply diagnostics have not failed.
The Bus OFF failure is not present, the CAN communication between TCM and PCM is not lost, there are no dual port RAM faults and the CAN message was read at least once.
•Set Condition:
The failure is detected if at least one of the following malfunctions is verified:
1) Toggle Bit Check and Parity Bit 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 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 specific signals bits (the PDL_POS) of the message content plus the toggle bit plus the parity bit is an even number. If the toggle bit value does not change or the signal parity is not verified for a calibrated amount of time then DTC U11D4 is set.
2) Signal Not Available Check: When the signal is not available, the PCM sends a SNA default value to the TCM. If the TCM reads this value then DTC U11D4 is set.
Possible Causes
PCM - INTERNAL ERROR
TRANSMISSION CONTROL MODULE
28 - DTC-Based Diagnostics / MODULE, Transmission Control (TCM), C635 DDCT / Diagnosis and Testing
U11D1-00-ENGINE SPEED MESSAGE RATIONALITY
Theory of Operation
This diagnostic checks the validity, availability and rationality of the engine speed signal which is sent by the Powertrain Control Module (PCM) via a CAN message. The diagnostic checks the validity by performing a CRC and message counter check to be sure the engine speed signal is continuously updated by the PCM and that it has a valid value. The diagnostic also checks the availability by checking the received value is not equal to the Signal Not Available (SNA) default value. Then the diagnostic checks the rationality by comparing the received engine speed to the odd or even clutch speed and to the odd or even input shaft speed. The clutch speed is measured directly from the clutch speed sensor and the input shaft speed is calculated based upon the driveline speed multiplied by the actual gear ratio. Any reference to odd or even is directly related to the actual odd or even gear engaged.
•When Monitored for Signal Invalid or Missing
Ignition key is ON and the engine is not in cranking mode.
Power supply must be between 7 volts and 24 volts and the Main Micro Processor (MMP) supply diagnostics have not failed.
The Bus OFF failure is not present, the CAN communication between TCM and PCM is not lost, there are no dual port RAM faults and the CAN message was read at least once.
•When Monitored for Signal Not Rational – Engine Speed Check for Zero Value
Ignition key is ON, the engine is not in cranking mode, there is no shift in progress, a gear is engaged, the clutch speed is greater than a threshold 250 rpm.
Power supply must be between 7 volts and 24 volts and the Main micro processor (MMP) supply diagnostics are not in failure.
The clutch position sensor has no electrical faults and the clutch speed has no rationality faults.
The Bus OFF failure is not present, the CAN communication between TCM and PCM is not lost, there are no dual port RAM faults and the CAN message was read at least once.
•When Monitored for Signal Not Rational – Engine Speed Compared to Odd or Even Clutch Speed and Odd or Even Input Shaft Speed
Ignition key is ON, the engine ignition status is on, the engine is not in cranking mode, there is no shift in progress, the engine torque is less than 100 Nm or the clutch temperature is less than 170 °C, a gear is engaged and the clutch speed is stable for more than 1 sec.
Power supply must be between 7 volts and 24 volts and the Main micro processor (MMP) supply diagnostics are not in failure.
The driveline speed signal has no faults.
The Bus OFF failure is not present, the CAN communication between TCM and PCM is not lost, there are no dual port RAM faults and the CAN message was read at least once.
•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.
Possible Causes
PCM - INTERNAL ERROR
BCM CAN BUS DTCS PRESENT
TRANSMISSION CONTROL MODULE
28 - DTC-Based Diagnostics / MODULE, Transmission Control (TCM), C635 DDCT / Diagnosis and Testing
U11D4-00-LOST PEDAL POSITION MESSAGE
Theory of Operation
This diagnostic checks the validity and availability of the gas pedal position signal which is sent by the Powertrain Control Module (PCM) via a CAN message. The diagnostic checks the validity by performing a CRC and message counter check to verify the gas pedal position signal is continuously updated by the PCM and that it has a valid value. The diagnostic also checks the availability by checking the received valid bit.
•When Monitored:
Ignition key is ON and the engine is not in cranking mode.
Power supply must be between 7 volts and 24 volts and the Main Micro Processor (MMP) supply diagnostics have not failed.
The Bus OFF failure is not present, the CAN communication between TCM and PCM is not lost, there are no dual port RAM faults and the CAN message was read at least once.
•Set Condition:
The failure is detected if at least one of the following malfunctions is verified:
1) Toggle Bit Check and Parity Bit 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 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 specific signals bits (the PDL_POS) of the message content plus the toggle bit plus the parity bit is an even number. If the toggle bit value does not change or the signal parity is not verified for a calibrated amount of time then DTC U11D4 is set.
2) Signal Not Available Check: When the signal is not available, the PCM sends a SNA default value to the TCM. If the TCM reads this value then DTC U11D4 is set.
Possible Causes
PCM - INTERNAL ERROR
TRANSMISSION CONTROL MODULE
28 - DTC-Based Diagnostics / MODULE, Transmission Control (TCM), C635 DDCT / Diagnosis and Testing
U11D4-00-LOST PEDAL POSITION MESSAGE
Theory of Operation
This diagnostic checks the validity and availability of the gas pedal position signal which is sent by the Powertrain Control Module (PCM) via a CAN message. The diagnostic checks the validity by performing a CRC and message counter check to verify the gas pedal position signal is continuously updated by the PCM and that it has a valid value. The diagnostic also checks the availability by checking the received valid bit.
•When Monitored:
Ignition key is ON and the engine is not in cranking mode.
Power supply must be between 7 volts and 24 volts and the Main Micro Processor (MMP) supply diagnostics have not failed.
The Bus OFF failure is not present, the CAN communication between TCM and PCM is not lost, there are no dual port RAM faults and the CAN message was read at least once.
•Set Condition:
The failure is detected if at least one of the following malfunctions is verified:
1) Toggle Bit Check and Parity Bit 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 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 specific signals bits (the PDL_POS) of the message content plus the toggle bit plus the parity bit is an even number. If the toggle bit value does not change or the signal parity is not verified for a calibrated amount of time then DTC U11D4 is set.
2) Signal Not Available Check: When the signal is not available, the PCM sends a SNA default value to the TCM. If the TCM reads this value then DTC U11D4 is set.
Possible Causes
PCM - INTERNAL ERROR
TRANSMISSION CONTROL MODULE