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, Powertrain Control (PCM) / Diagnosis and Testing
P0339-00-CRANKSHAFT POSITION SENSOR INTERMITTENT
Theory of Operation
The Crankshaft Position (CKP) Sensor circuits consist of a Powertrain Control Module (PCM) supplied 5-Volt reference circuit, low reference circuit and an output signal circuit. The CKP Sensor is an internally magnetic biased digital output integrated circuit sensing device. The sensor detects magnetic flux changes between the peaks and valleys of a tone wheel on the crankshaft. Each tooth on the tone wheel is evenly spaced with missing teeth used as a reference gap. The CKP Sensor produces an ON/OFF DC voltage of varying frequency, reference output pulses per crankshaft revolution. The frequency of the CKP Sensor output depends on the velocity of the crankshaft. The CKP Sensor sends a digital signal to the PCM , which represents an image of the crankshaft tone wheel. The PCM uses each CKP signal pulse to determine crankshaft speed and decodes the crankshaft tone wheel reference gap to identify crankshaft position. This information is then used to sequence the ignition timing and fuel injection events for the engine. The PCM also uses CKP Sensor output information to determine the crankshaft position relative to the camshaft. This information is used to identify cylinder misfires and to control the CMP actuator if equipped.
When Monitored and Set Conditions
When Monitored:
•This diagnostic runs with the engine cranking or running.
Set Conditions:
•When the CKP Sensor failure counter reaches 20.
Default Actions:
•MIL light will illuminate.
Possible Causes
5-VOLT SUPPLY CIRCUIT SHORTED TO VOLTAGE
5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND
5-VOLT SUPPLY CIRCUIT SHORTED TO THE CKP SENSOR GROUND CIRCUIT
5-VOLT SUPPLY CIRCUIT OPEN/HIGH RESISTANCE
CKP SIGNAL CIRCUIT SHORTED TO VOLTAGE
CKP SIGNAL CIRCUIT SHORTED TO GROUND
CKP SIGNAL CIRCUIT SHORTED TO THE CKP SENSOR GROUND CIRCUIT
CKP SIGNAL CIRCUIT OPEN/HIGH RESISTANCE
CKP SENSOR GROUND CIRCUIT OPEN/HIGH RESISTANCE
CRANKSHAFT POSITION SENSOR
POWERTRAIN CONTROL MODULE (PCM)
28 - DTC-Based Diagnostics / MODULE, Powertrain Control (PCM) / Diagnosis and Testing
P0137-00-O2 SENSOR 1/2 CIRCUIT LOW
Theory of Operation
The 4-Wire oxygen sensor is equipped with a galvanic battery that typically generates a voltage signal between 0.0 volts and 1.0 volts. The 4-Wire O2 Sensor also includes a heating element that keeps the sensor at proper operating temperature during all operating modes. Maintaining correct sensor temperature at all times allows the system to enter into closed loop operation sooner. Also, it allows the system to remain in closed loop operation during periods of extended idle.
A bias voltage in the Powertrain Control Module (PCM) shifts the signal voltage to fluctuate between 2.5 volts and 3.5 volts, depending upon the oxygen content of the exhaust gas. When a large amount of oxygen is present (caused by a lean air/fuel mixture) the sensor produces a low voltage. When there is a lesser amount of oxygen present (caused by a rich air/fuel mixture) it produces a higher voltage. By monitoring the oxygen content and converting it to electrical voltage, the sensor acts as a rich-lean switch.
In Open Loop operation the PCM ignores input from the O2 sensors. In Closed Loop operation the PCM monitors the O2 sensor's input (along with other inputs) and adjusts the injector pulse width accordingly based on pre-programmed (fixed) values and inputs from other sensors. The PCM also compares upstream and downstream O2 Sensor inputs to calculate the catalytic convertor oxygen storage capacity and converter efficiency.
When Monitored and Set Conditions
When Monitored: This diagnostic runs continuously when the following conditions are met:
•With the engine running.
•O2 Sensor is in closed loop mode.
Set Conditions:
•The Powertrain Control Module (PCM) detects that the O2 Sensor 1/2 signal voltage is below the minimum calibrated threshold.
Default Actions:
•The MIL light will illuminate.
Possible Causes
O2 SENSOR RETURN CIRCUIT SHORTED TO GROUND
O2 SENSOR 1/2 SIGNAL CIRCUIT SHORTED TO GROUND
O2 SENSOR 1/2 SIGNAL CIRCUIT SHORTED TO THE O2 SENSOR RETURN CIRCUIT
O2 SENSOR 1/2 SIGNAL CIRCUIT SHORTED TO THE O2 SENSOR 1/2 HEATER CONTROL CIRCUIT
O2 SENSOR 1/2
POWERTRAIN CONTROL MODULE (PCM)
28 - DTC-Based Diagnostics / MODULE, Powertrain Control (PCM) / Diagnosis and Testing
P2096-00-DOWNSTREAM FUEL TRIM SYSTEM 1 LEAN
Theory of Operation
The 4-Wire oxygen sensor is equipped with a galvanic battery that typically generates a voltage signal between 0.0 volts and 1.0 volts. The 4-Wire O2 Sensor also includes a heating element that keeps the sensor at proper operating temperature during all operating modes. Maintaining correct sensor temperature at all times allows the system to enter into closed loop operation sooner. Also, it allows the system to remain in closed loop operation during periods of extended idle.
A bias voltage in the Powertrain Control Module (PCM) shifts the signal voltage to fluctuate between 2.5 volts and 3.5 volts, depending upon the oxygen content of the exhaust gas. When a large amount of oxygen is present (caused by a lean air/fuel mixture) the sensor produces a low voltage. When there is a lesser amount of oxygen present (caused by a rich air/fuel mixture) it produces a higher voltage. By monitoring the oxygen content and converting it to electrical voltage, the sensor acts as a rich-lean switch.
In Open Loop operation the PCM ignores input from the O2 sensors. In Closed Loop operation the PCM monitors the O2 sensor's input (along with other inputs) and adjusts the injector pulse width accordingly based on pre-programmed (fixed) values and inputs from other sensors. The PCM also compares upstream and downstream O2 Sensor inputs to calculate the catalytic convertor oxygen storage capacity and converter efficiency.
When Monitored and Set Conditions
When Monitored: This diagnostic runs when the following conditions are met:
•With the engine running in closed loop mode.
•Ambient/battery temperature above -6.7° C (20° F).
•Altitude below 2590.8 m (8500 ft).
Set Conditions:
•The conditions that cause this diagnostic to fail is when the Upstream O2 Sensor becomes biased from an exhaust leak, O2 Sensor contamination or some other extreme operating condition. The Downstream O2 Sensor is considered to be protected from extreme environments by the catalyst. The PCM monitors the Downstream O2 Sensor feedback control, called downstream fuel trim, to detect any shift in the Upstream O2 Sensor target voltage from nominal target voltage. The value of the downstream fuel trim is compared with the lean thresholds. Every time the value exceeds the calibrated threshold, a fail timer will increment and mass flow through the exhaust is accumulated. If the fail timer and accumulated mass flow exceed the fail thresholds, the test fails and the diagnostic stops running for that trip.
Default Actions:
•MIL light will illuminate.
Possible Causes
EXHAUST LEAK
FUEL DELIVERY SYSTEM
O2 SENSOR, WIRING, OR CONNECTORS
ENGINE MECHANICAL SYSTEM
POWERTRAIN CONTROL MODULE (PCM)
U0415-00-IMPLAUSIBLE DATA RECEIVED FROM ABS
Perform the COMMUNICATION PRE-DIAGNOSTIC PROCEDURE. (Refer to 28 - DTC-Based Diagnostics/MODULE, Body Control (BCM) /Standard Procedure).
28 - DTC-Based Diagnostics / MODULE, Body Control (BCM) / Standard Procedure
COMMUNICATION PRE-DIAGNOSTIC PROCEDURE
Communication Pre-Diagnostic Procedure
1.CHECK FOR POSSIBLE CAUSES
NOTE: For an in-depth explanation of the CAN system operation, refer to the DESCRIPTION in Section 8E, COMMUNICATION.
1. Check Battery for proper State of Charge (SOC) and Charging System for proper operation. (Refer to 08 - Electrical/Charging/Diagnosis and Testing) .
2. With a scan tool, check all electronic Control Modules for battery and ignition voltage related DTCs.
3. Check for and perform all Service Bulletins that could be related to the customer complaint.
4. Check aftermarket accessories for proper installation. (Check for improper electrical connections and fasteners that may be contacting wire harnesses.)
5. With a scan tool, check all electronic Control Modules for software updates that are related to the customer complaint. Update Control Module(s) as necessary.
6. Check wire harnesses for collision related damage.
Were any problems found?
Yes
•Repair the problem as necessary.
•With a scan tool, erase DTCs from the related electronic Control Modules and perform the appropriate VERIFICATION TEST. If a VERIFICATION TEST is not available for that module, perform the BCM VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Body Control (BCM) /Standard Procedure).
No
•Go To 2
2.CHECK ELECTRONIC CONTROL MODULES FOR VEHICLE CONFIGURATION DTCS
NOTE:
A Configuration DTC indicates that an Electronic Control Module (ECU) is not programmed with information that is specific to the vehicle (VIN, mileage, etc.). If an ECU is not configured properly, serial data communication failures could exist. The following list includes, but is not limited to, DTC descriptors that indicate a Configuration DTC.
•ECU Configuration Mismatch - Not Configured
•ECU Unable To Configure
•Implausible/Missing ECU Network Configuration Data
•Implausible/Missing Vehicle Configuration Data
•Implausible Vehicle Configuration
•Incorrect Variant/Configuration
•PROXI Not Programmed
•Restore Vehicle Configuration
•Vehicle Configuration Mismatch
•Vehicle Configuration Not Programmed
1. With the scan tool, generate a Vehicle Scan Report.
2. With the Vehicle Scan Report, check all ECUs for Configuration DTCs.
Are any Configuration DTCs set?
Yes
•Configure the ECU(s) as necessary in accordance with the Service Information.
•Perform the appropriate VERIFICATION TEST. If a VERIFICATION TEST is not available for that electronic Control Module, perform the BCM VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Body Control (BCM) /Standard Procedure).
No
•Go To 3
3.CHECK ELECTRONIC CONTROL MODULES FOR ACTIVE COMMUNICATION RELATED DTCS
1. Refer to the Vehicle Scan Report.
Are any Communication related DTCs active?
Yes
•Go To 4
No
•Go To 5
4.CHECK ACTIVE DTCS
1.
Refer to the Vehicle Scan Report.
NOTE: Diagnose Lost Communication DTCs (not to be confused with CAN Bus Off or Can Bus Performance DTCs) before diagnosing other CAN related DTCs.
Which type of Communication DTC is active?
Lost Communication
•Go To 7
Implausible Data, Implausible Signal, Missing Message, or Invalid Data
•Go To 9
5.CHECK STORED DTCS
1. Refer to the Vehicle Scan Report.
NOTE: Diagnose all Lost Communication DTCs before diagnosing other CAN related DTCs.
Which type of Communication DTC is stored?
Lost Communication
•Perform the STORED LOST COMMUNICATION DTCS procedure. (Refer to 29 - Non-DTC Diagnostics/Communication/Diagnosis and Testing) .
Implausible Data, Implausible Signal, Missing Message, or Invalid Data
•Go To 6
6.CHECK OFFENDING CONTROL MODULE FOR DTCS
NOTE: The ‘Offending Control Module’ is the module that the Implausible DTC is set against.
1. Refer to the Vehicle Scan Report.
Are any DTCs set in the Offending Control Module?
Yes
•Refer to the appropriate diagnostic procedure.
No
•Go To 11
7.CHECK FOR MULTIPLE LOST COMMUNICATION DTCS
1. Refer to the Vehicle Scan Report.
Choose the scenario that best describes the condition of the vehicle from the list below:
One module is reporting a Lost Communication DTC against a single Control Module.
•Go To 8
Multiple Control Modules are reporting a Lost Communication DTC against a single Control Module.
•Perform the NO RESPONSE diagnostic procedure for the Control Module that is not communicating. (Refer to 29 - Non-DTC Diagnostics/Communication/Diagnosis and Testing) .
8.CHECK OFFENDING CONTROL MODULE FOR COMMUNICATION
NOTE: The ‘Offending Control Module’ is the module that the Loss of Communication DTC is set against.
1. Refer to the Vehicle Scan Report.
Is the Offending Control Module active on the bus?
Yes
•Replace the Reporting Control Module in accordance with the Service Information.
•Perform the appropriate VERIFICATION TEST. If a VERIFICATION TEST is not available for that Control Module, perform the BCM VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Body Control (BCM) /Standard Procedure).
No
•Perform the NO RESPONSE diagnostic procedure for the module that is not communicating. (Refer to 29 - Non-DTC Diagnostics/Communication/Diagnosis and Testing) .
9.CHECK OFFENDING CONTROL MODULE FOR DTCS
NOTE: The ‘Offending Control Module’ is the module that the Implausible Data, Implausible Signal, Missing Message, or Invalid Data DTC is set against.
1. Refer to the Vehicle Scan Report.
With the scan tool, check the Offending Control Module for non-U-code DTCs that are related to the U-code that is set, or related to the customer complaint if the U-code DTC name is not clear about which signal is faulted.
Yes
•Refer to the appropriate diagnostic procedure.
No
•Go To 10
10.CHECK OTHER CONTROL MODULES FOR RELATED NON U-CODE DTCS
NOTE: IMPORTANT: Some Control Modules simply pass information from one Control Module to the other. In some cases, a U-code DTC may be set that implicates the “pass-through” module that sent the information. For example, if an Engine Coolant Temperature (ECT) Sensor DTC is set in the Powertrain Control Module (PCM), the HVAC module may set an “Implausible Data from BCM” DTC because the BCM is the module that normally passes that information from the PCM to the HVAC module. However, the BCM may not set any DTCs related to the faulted ECT Sensor because the BCM does not use the ECT information. In this case, the PCM ECT DTC should be diagnosed before the Implausible Data DTC. If you suspect a scenario like this, diagnose the non U-code DTC(s) before diagnosing any Implausible Data, Implausible Signal, Invalid Data, or Missing Message DTCs.
1. With the scan tool, check all other Control Modules for non-U-code DTCs that are related to the U-code that is set, or related to the customer complaint if the U-code DTC name is not clear about which signal is faulted.
Is a related non U-code DTC set in another Control Module?
Yes
•Diagnose the related DTC. Refer to the appropriate Diagnostic Procedure.
No
•Replace the Offending Control Module in accordance with the Service Information.
•Perform the appropriate VERIFICATION TEST. If a VERIFICATION TEST is not available for that module, perform the BCM VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Body Control (BCM) /Standard Procedure).
11.CHECK RELATED WIRE HARNESS CONNECTIONS
1. Disconnect all related wire harness connectors.
2. Disconnect all related in-line wire harness connections (if equipped).
3. Inspect wire harness connectors, component connectors, and all male and female terminals for the following conditions:
•Proper connector installation.
•Damaged connector locks.
•Corrosion.
•Signs of water intrusion.
•Weather seal damage (if equipped).
•Bent terminals.
•Overheating due to a poor connection (terminal may be discolored due to excessive current draw).
•Terminals that have been pushed back into the connector cavity.
•Perform a terminal drag test on each connector terminal to verify proper terminal tension.
Repair any conditions that are found.
4. Reconnect all related wire harness connectors. Be certain that all wire harness connectors are fully seated and the connector locks are fully engaged.
5. Reconnect all in-line wire harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
6. With the scan tool, erase DTCs.
7. Using the Vehicle Scan Report, operate the vehicle in the conditions that set the DTC.
8. With the scan tool, read DTCs.
Did the DTC return?
Yes
•If there is a history of this DTC setting multiple times, replace the Offending Control Module in accordance with the Service Information.
•Perform the appropriate VERIFICATION TEST. If a VERIFICATION TEST is not available for that Control Module, perform the BCM VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Body Control (BCM) /Standard Procedure).
No
•Perform the appropriate VERIFICATION TEST. If a VERIFICATION TEST is not available for that Control Module, perform the BCM VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Body Control (BCM) /Standard Procedure).
•Test complete.