weave2k0
New CEG'er
found this on motorcraft's website:
http://www.motorcraftservice.com/vdirs/diagnostics/pdf/obdsm986.pdf pg 42
CD4E (FWD) Transmission
(has turbine speed sensor)
Transmission Inputs
The Analog Transmission Range (TR) sensor provides a single analog input to the PCM. The voltage corresponds
to the driver-selected gear position (Park, Rev, Neutral, OD, 2, 1). This input is checked for opens and shorts.
(P0707, P0708)
The Vehicle Speed Sensor (VSS), Turbine Shaft Speed (TSS) sensor and Output Shaft Speed (OSS) sensor, if
equipped, are analog inputs that are checked for rationality. If the engine rpm is above the torque converter stall
speed and engine load is high, it can be inferred that the vehicle must be moving. If there is insufficient output from
the VSS sensor, a malfunction is indicated (P0500). If there is insufficient output from the TSS sensor, a
malfunction is indicated (P0715). If there is insufficient output from the OSS sensor, a malfunction is indicated
(P0720).
Transmission Outputs
Shift Solenoids
The Shift Solenoid (SSA and SSB) output circuits are checked for opens and shorts by the PCM by monitoring the
status of a feedback circuit from the output driver (P0750 SSA, P0755 SSB).
The shift solenoids are also checked functionally. Since the CD4E transmission does have a turbine speed sensor,
the actual gear ratio can be computed any time the transmission is not shifting and the vehicle is not coasting. An
actual gear ratio is computed in each gear and compared to the predicted gear ratio in order to determine the
actual gear pattern obtained during an up-shift sequence. This information is then used to determine which shift
solenoid is malfunctioning. For example, if SS1 is shorted to power or is hydraulically stuck in that position, the 1-2-
3-4 commanded shifts will actually result in a 1-1-4-4 shift pattern. The unique shift pattern is used to determine
which shift solenoid is malfunctioning. (P0751 SSA, P0756 SSB)
Torque Converter Clutch
The Torque Converter Clutch (TCC) output circuit is a duty-cycled output that is checked electrically for opens and
shorts by the PCM by monitoring the status of a feedback circuit from the output driver (P0743).
The TCC solenoid is checked functionally by evaluating torque converter slip under steady state conditions when
the torque converter is fully applied. If the slip exceeds the malfunction thresholds when the TCC is commanded
on, a TCC malfunction is indicated (P1744). If there is no slip when the TCC is commanded off, a TCC malfunction
is indicated (P1742)
Electronic Pressure Control
The EPC solenoid is a variable force solenoid that controls line pressure in the transmission. The EPC solenoid
has a feedback circuit in the PCM that monitors EPC current. If the current indicates a short to ground (low
pressure), engine torque may be reduced to prevent damage to the transmission. (P1747, PCA)
http://www.motorcraftservice.com/vdirs/diagnostics/pdf/obdsm986.pdf pg 42
CD4E (FWD) Transmission
(has turbine speed sensor)
Transmission Inputs
The Analog Transmission Range (TR) sensor provides a single analog input to the PCM. The voltage corresponds
to the driver-selected gear position (Park, Rev, Neutral, OD, 2, 1). This input is checked for opens and shorts.
(P0707, P0708)
The Vehicle Speed Sensor (VSS), Turbine Shaft Speed (TSS) sensor and Output Shaft Speed (OSS) sensor, if
equipped, are analog inputs that are checked for rationality. If the engine rpm is above the torque converter stall
speed and engine load is high, it can be inferred that the vehicle must be moving. If there is insufficient output from
the VSS sensor, a malfunction is indicated (P0500). If there is insufficient output from the TSS sensor, a
malfunction is indicated (P0715). If there is insufficient output from the OSS sensor, a malfunction is indicated
(P0720).
Transmission Outputs
Shift Solenoids
The Shift Solenoid (SSA and SSB) output circuits are checked for opens and shorts by the PCM by monitoring the
status of a feedback circuit from the output driver (P0750 SSA, P0755 SSB).
The shift solenoids are also checked functionally. Since the CD4E transmission does have a turbine speed sensor,
the actual gear ratio can be computed any time the transmission is not shifting and the vehicle is not coasting. An
actual gear ratio is computed in each gear and compared to the predicted gear ratio in order to determine the
actual gear pattern obtained during an up-shift sequence. This information is then used to determine which shift
solenoid is malfunctioning. For example, if SS1 is shorted to power or is hydraulically stuck in that position, the 1-2-
3-4 commanded shifts will actually result in a 1-1-4-4 shift pattern. The unique shift pattern is used to determine
which shift solenoid is malfunctioning. (P0751 SSA, P0756 SSB)
Torque Converter Clutch
The Torque Converter Clutch (TCC) output circuit is a duty-cycled output that is checked electrically for opens and
shorts by the PCM by monitoring the status of a feedback circuit from the output driver (P0743).
The TCC solenoid is checked functionally by evaluating torque converter slip under steady state conditions when
the torque converter is fully applied. If the slip exceeds the malfunction thresholds when the TCC is commanded
on, a TCC malfunction is indicated (P1744). If there is no slip when the TCC is commanded off, a TCC malfunction
is indicated (P1742)
Electronic Pressure Control
The EPC solenoid is a variable force solenoid that controls line pressure in the transmission. The EPC solenoid
has a feedback circuit in the PCM that monitors EPC current. If the current indicates a short to ground (low
pressure), engine torque may be reduced to prevent damage to the transmission. (P1747, PCA)