Allison 3000 & 4000 Gen 4 Fault Code: P063F Auto Configuration Engine Coolant Temp Input Not Present

Description

DIAGNOSTIC RESPONSE:
None

CIRCUIT DESCRIPTION:
The engine coolant temperature can be specified by:
1. Autodetect of the ECT sensor source (prior to MY09 new release calibrations). Calibrations that have rolled forward from a previous software release will continue to have the autodetect source available in later CIN versions.
2. Use of CMC Override Engine Coolant source with the diagnostic tool to set ECT sensor source (Analog, AE J1939, SAE J1587, PWM, or Autodetect). Choose “Autodetect” from the CMC list only if the calibration is prior to MY09 or the autodetect feature has rolled into later CIN versions.
3. Communication link type selected during calibration request process for MY09 and later calibrations.

NOTE: New MY09 and later calibrations that did not maintain autodetect, i.e., did not roll forward from earlier software, should not be reprogrammed by the CMC Override Engine Coolant Source. This may disable some datalink features for the calibration’s specified communication link type. If a different ECT sensor source is needed other than that specified by the communication link type, calibrate with a new CIN that enables the desired ECT sensor source.

Engine coolant temperature is monitored by the Transmission Control Module (TCM) to determine if retarder capacity should be reduced based on elevated engine coolant temperature. Additionally, closed throttle downshifts may be raised. The coolant temperature input must be enabled by calibration and programmed as enabled. Three levels of preselect downshifts are available through programming. The engine coolant temperature may also be disabled through programming as well.

ECT sensor configuration is determined by autodetect logic for MY08 and earlier calibrations. The logic counts down for a total of 25 engine starts while recording detections of candidate engine coolant temperature sources. The engine coolant temperature source can either be an analog voltage detected on W135 or a message over SAE J1939, SAE J1708/J1587, or IES CAN. A confidence flag sets once a source is detected for five consecutive engine starts. Multiple sources detected before a confidence flag is set or multiple confidence flags will result in the highest priority source being used as the engine coolant temperature source. Multiple sources can be detected on a single engine start cycle. When the countdown period is complete, the software uses the highest priority engine coolant source having a confidence flag set and the autodetect logic stops.

NOTE: Most autodetect installations (prior to MY09 software) use datalink messages, SAE J1939 (most common), SAE J1708/J1587, or IES CAN for the ECT message instead of an analog input (W135) for ECT sensor. The vehicle OEM has warranty responsibility for integration issues with any SAE J1939, SAE J1708/J1587, IES CAN links and any related vehicle controllers that cause the engine coolant source not to be autodetected.

CONDITIONS FOR RUNNING THE DTC:
1. Autodetect logic enabled.
2. TCM initialized normally and engine speed is above 200 rpm for more than 5 seconds.
3. ECT sensor source undetected after 25 engine starts.

CONDITIONS FOR SETTING THE DTC:
DTC P063F sets if the TCM fails to detect the ECT sensor source.

ACTION TAKEN WHEN THE DTC SETS:
1. The CHECK TRANS light does not illuminate.
2. The DTC is stored in the TCM history.
3. The TCM uses default ECT sensor values.

CONDITIONS FOR CLEARING THE DTC/CHECK TRANS LIGHT:
The diagnostic tool may be used to clear the DTC from the TCM history. The TCM automatically clears the DTC from the TCM history if the vehicle completes 40 warm-up cycles without the DTC recurring.

DIAGNOSTIC AIDS:
DTC P063F may be caused by:
1. Incorrect engine calibration.
2. Incorrect transmission calibration.
3. Engine or Vehicle that does not support required datalink messages.
4. Communication link problem.
5. Missing or defective ECT sensor or engine coolant temperature circuits and components.
6. Defective TCM.

Review applicable information in Auto-detect Logic, General Troubleshooting of Performance Complaints, Control system and Transmission Specifications, and other related information.