Section 07-01: Transmission, Automatic, E4OD | 1997 F-250 Heavy Duty, F-350 and F-Super Duty Workshop Manual |
Electronic System Description
The following pages provide a brief description of each of the sensors and actuators used with the E4OD transmission. The function of each of these components and the associated symptoms and diagnostic trouble codes (DTCs) are also given.
E4OD Automatic Transmission Electronic Control System Component Locator
Item | Part Number | Description |
---|---|---|
1 | — | MAP/BARO Sensor |
2 | 9B989 | Throttle Position Sensor |
3 | — | Engine Oil Temperature (EOT) Sensor (7.3L DI Diesel) |
4 | — | Intake Air Temperature (IAT) Sensor (7.3L DI Diesel) |
5 | — | Transmission Control Switch (TCS) and Transmission Control Indicator Lamp (TCIL) |
6 | 12A650 | Powertrain Control Module |
7 | — | Transmission Solenoid Body |
8 | — | 4x4 Low (4x4 L) |
9 | 9E731 | Vehicle Speed Sensor (VSS) (Model-Dependent) |
10 | 7A247 | Transmission Range (TR) Sensor |
11 | — | Accelerator Pedal (AP) Sensor (7.3L DI Diesel) |
12 | — | Programmable Speedometer/Odometer Module (PSOM) |
13 | 13480 | Stoplight Switch |
14 | — | Electronic Ignition (EI) System |
15 | — | Distributor Ignition (DI) (Gasoline Engine) |
16 | — | Camshaft Position (CMP) Sensor (7.3L DI Diesel) |
17 | 2884 | Air Conditioning (A/C) Clutch |
18 | 12B579 | Mass Air Flow Sensor |
19 | — | Barometric Pressure (BARO) Sensor (7.3L DI Diesel) |
Manifold Absolute Pressure (MAP) Sensor — Gasoline Engines
On gasoline engines, the manifold absolute pressure sensor (MAP sensor) (9F479) senses atmospheric pressure to produce an electrical signal. The frequency of this signal varies with intake manifold pressure. The powertrain control module (PCM) (12A650) monitors this signal to determine altitude. The PCM then adjusts the E4OD shift schedule and EPC pressure for altitude. On diesel engines, the MAP sensor measures boost pressure. The PCM monitors this signal and adjusts EPC pressure.
Symptoms
Firm shift feel, late shifts at altitude
Diagnostic Trouble Codes
126-129, P0235-P0237
Throttle Position (TP) Sensor 9B989
The throttle position sensor (TP sensor) (9B989) is a potentiometer that is mounted on the throttle body (9E926). The throttle position sensor detects the position of the throttle plate or lever and sends this information as a voltage signal to the powertrain control module. If the throttle position sensor or related circuits fail to operate in a normal manner, the powertrain control module will recognize that the throttle position sensor signal is out of specification. The powertrain control module will then operate the E4OD transmission at a higher line pressure to prevent transmission damage. This high line pressure causes harsh upshift and engagements. Used as an input to determine shift scheduling and electronic pressure control.
Symptoms
Harsh engagements, firm shift feel, abnormal shift schedule, abnormal or no torque converter clutch operation. May flash transmission control indicator lamp.
Diagnostic Trouble Codes
121, 122, 123, 124, 125, 167, P0121, P0122, P0123, P1120, P1121, P1124, P1125
Transmission Control Switch (TCS) and Transmission Control Indicator Lamp (TCIL)
The transmission control switch (TCS) is a momentary contact switch. When the switch is pressed, a signal is sent to the powertrain control module. The powertrain control module then energizes the transmission control indicator lamp and the coast clutch solenoid, applying the coast clutch to provide engine braking and cancels fourth gear operation. The TCIL indicates overdrive cancel mode activated (lamp on), electronic pressure control circuit shorted or monitored sensor failure (lamp flashing).
Sensor
Transmission control switch
Symptoms
No overdrive cancel when switch is cycled
Diagnostic Trouble Codes
632, P1780, tested during Key On Engine Off (KOEO) On-Board Diagnostic only
Actuator
Transmission control indicator lamp
Symptoms
Failed on — overdrive cancel mode always indicated, no flashing for electronic pressure control circuit shorted. Failed off — overdrive cancel mode never indicated, no flashing for electronic pressure control circuit shorted, also may be due to a bad fuse. Erratic operation (flashing) may be due to a wiring concern.
Diagnostic Trouble Code
631, P1779
Powertrain Control Module (PCM)
On vehicles equipped with gasoline engines, the operation of the E4OD automatic transmission is controlled by the powertrain control module. Many input sensors provide information to the powertrain control module, which then controls the actuators that affect transmission operation.
On vehicles equipped with diesel engines, the operation of the E4OD automatic transmission is also controlled by the powertrain control module. However, some of the input sensors are different.
Transmission Solenoid Body
The powertrain control module controls the E4OD transmission operation through four on/off solenoids and one variable force solenoid. These solenoids and transmission fluid temperature sensor are housed in the transmission solenoid body assembly. All are part of the transmission solenoid body and are not replaced individually. Additionally, in 1995, the protection diodes that were on the solenoid body were moved to the PCM.
The four on/off solenoids operate in the following manner.
Transmission Fluid Temperature (TFT) Sensor
The transmission fluid temperature sensor is located on the solenoid body assembly in the transmission sump. It is a temperature-sensitive device called a thermistor. The resistance value of the transmission fluid temperature sensor will vary with temperature change. The powertrain control module monitors voltage across the transmission fluid temperature sensor to determine the temperature of the transmission fluid. The powertrain control module uses this signal to determine whether a cold start shift schedule is necessary. The cold start shift schedule lowers shift speeds to allow for the reduced performance of cold engine operation. The powertrain control module also uses the transmission fluid temperature sensor input to adjust electronic pressure control pressure for temperature effects and to inhibit torque converter clutch operation during the warm-up period.
Symptoms
Torque converter clutch and stabilized shift schedule happens too soon after a cold start. Code 657 or P1783 indicates transmission fluid temperature exceeds 132°C (270°F) and results in increased EPC pressure and torque converter clutch engagement. May flash transmission control indicator lamp.
Diagnostic Trouble Codes
636, 637, 638, 657, P0712, P0713, P1711, P1783
Electronic Pressure Control (EPC) Solenoid
CAUTION: The electronic pressure control pressure output from the variable force solenoid is NOT adjustable. Any modification to the electronic pressure control solenoid will affect the transmission warranty.
The electronic pressure control solenoid is a variable force solenoid. The variable-force type solenoid is an electrohydraulic actuator combining a solenoid and a regulating valve. It supplies electronic pressure control that regulates transmission line pressure and line modulator pressure. This is done by producing resisting forces to the main regulator and the line modulator circuits. These two pressures control clutch application pressures.
Symptoms
Failed on — minimum electronic pressure control pressure (minimum transmission torque capacity). Limited engine torque (partial fuel shutoff, heavy misfire). Flashing transmission control indicator lamp. Failed off — maximum electronic pressure control pressure, harsh engagements and shifts. May flash transmission control indicator lamp.
Diagnostic Trouble Codes
6241, 6251, P17461, P17471
NOTE: 1Output circuit check, generated only by electrical condition.
Torque Converter Clutch (TCC) Solenoid
The torque converter clutch solenoid (TCC solenoid) provides torque converter clutch control by shifting the converter clutch control valve to apply or release the torque converter clutch.
Symptoms
Failed on — engine stalls in drive at idle low speeds with brake applied or MANUAL 2. Failed off — converter clutch never engages. May flash transmission control indicator lamp.
Diagnostic Trouble Codes
6291, P07412, P07431, P1742, P1743, P1744
NOTE: 1Output circuit check, generated only by electrical condition.
2May also be generated by other non-electronic-related transmission hardware conditions.Coast Clutch Solenoid (CCS)
NOTE: On certain applications, the coast clutch is controlled by the PCM in the overdrive position (TCS OFF) in gears 1, 2, and 3.
The coast clutch solenoid provides coast clutch control by shifting the coast clutch shift valve. The solenoid is activated by pressing the transmission control switch or by selecting the 1 or 2 range with the transmission range selector lever. In MANUAL 1 and 2, the coast clutch is controlled by the solenoid and also hydraulically as a fail-safe to ensure engine braking. In reverse, the coast clutch is controlled hydraulically and the solenoid is not on.
Symptoms
Failed on — third gear engine braking with (D) range selected. Failed off — no third gear engine braking in overdrive cancel.
Diagnostic Trouble Code:
6261, 6282, 6431, 6521, P07412, P07431, P17541
NOTE: 1Output circuit check, generated only by electrical condition.
2May also be generated by other non-electronic-related transmission hardware conditions.Shift Solenoids 1 and 2
Shift solenoids 1 and 2 provide gear selection of first through fourth gears by controlling the pressure to the three shift valves.
Shift Solenoid 1
Improper gear selection, depending on failure mode and manual lever position. Refer to the Shift Solenoid Operation Chart in the Specifications portion of this section. May flash transmission control indicator lamp.
Diagnostic Trouble Codes
P6172, 6182, 6192, 6211, P07501, P0751, P07812, P07822, P07832
NOTE: 1Output circuit check, generated only by electrical condition.
2May also be generated by other non-electronic-related transmission hardware conditions.Shift Solenoid 2
Improper gear selection, depending on failure mode and manual lever position. Refer to the Shift Solenoid Operation Chart in the Specifications portion of this section. May flash transmission control indicator lamp.
Diagnostic Trouble Codes
6172, 6182, 6192, 6221, P07551, P07811, P07822, P07832, P0756
NOTE: 1Output circuit check, generated only by electrical condition.
2May also be generated by other non-electronic-related transmission hardware conditions.Shift Solenoid Operation Chart
Refer to the Specifications portion of this section for the Shift Solenoid Operation Chart. The chart shows normal solenoid operation for given operating modes.
4x4 Low (4x4L) Switch
The low range switch is located on the transfer case cover (7165). It provides an indication of when the 4x4 transfer case gear system is in the LOW range. Modifies shift schedule for 4x4L transfer case gear ratio.
Symptoms
Failed on — Early shift schedule in 4x2 and 4x4H. Failed off — Shifts delayed in 4x4L. If the 4x4 low indicator light fuse is blown, the transmission (7003) will shift according to 4x4 low shift schedule regardless of transfer case position.
Diagnostic Trouble Codes
633, 691, P1729, P1781
Vehicle Speed Sensor (VSS) 9E731
The vehicle speed sensor (VSS) (model-dependent) is a variable reluctance sensor that sends an AC/frequency signal to the powertrain control module. The vehicle speed sensor signal is used by the powertrain control module to calculate vehicle speed in mph and determine shift scheduling and electronic pressure control.
Symptoms
Harsh engagements, firm shift feel, abnormal shift schedule; unexpected downshifts can occur at closed throttle, abnormal torque converter clutch operation or torque converter clutch engages only at wide-open throttle. May flash transmission control indicator lamp.
Diagnostic Trouble Codes
452, P0500, P1500, P1501, P0503
Transmission Range (TR) Sensor 7A247
The powertrain control module sends voltage to the Transmission Range (TR) sensor. The TR sensor incorporates a series of step-down resistors which act as a voltage divider. The powertrain control module monitors this voltage which corresponds to the positon of the transmission range selector lever (P, R, N, (D), 2 or 1). The powertrain control module uses this information to determine the desired gear and electronic pressure control pressure. The TR sensor is located on the outside of the transmission at the manual lever.
Symptoms
Harsh engagements, firm shift feel.
Diagnostic Trouble Codes
634, 654, 667, 668, P0705, P0707, P0708, P1705
Accelerator Pedal (AP) Sensor — 7.3L DI Diesel Only
The accelerator pedal (AP) sensor is mounted on the accelerator pedal on vehicles equipped with a 7.3L DI diesel engine. The AP sensor detects the position of the accelerator pedal and sends this information as a voltage signal to the PCM. If the AP sensor or related circuits fail to operate in a normal manner, the powertrain control module will recognize that the AP sensor signal is out of specification. The powertrain control module will then operate the E4OD transmission at a higher line pressure to prevent transmission damage. This high line pressure causes harsh upshift and engagements. Used as an input to determine shift scheduling and electronic pressure control.
Symptoms
Harsh engagements, firm shift feel, abnormal shift schedule, abnormal or no torque converter clutch operation. May flash transmission control indicator lamp.
Diagnostic Trouble Codes
122, 123, P0122, P0123
Programmable Speedometer/Odometer Module (PSOM)
The programmable speedometer/odometer module receives input from the rear brake anti-lock sensor, which is mounted on the rear axle differential housing. The PSOM processes this input signal information and relays it to the powertrain control module and the speed control module. This signal tells the powertrain control module the vehicle speed in miles per hour (mph). Used as an input in determining shift scheduling and electronic pressure control.
Symptoms
Harsh engagements, firm shift feel, abnormal shift schedule, unexpected downshifts may occur at closed throttle, abnormal torque converter clutch operation or engages only at wide-open throttle (WOT). May flash transmission control indicator lamp.
Diagnostic Trouble Codes
452, P0500, P1500, P1501, P0503
Stoplight Switch 13480
The stoplight switch (13480) tells the powertrain control module when the brakes are applied. The switch is closed when the brakes are applied and open when they are released. The PCM uses this signal to disengage the torque converter clutch when the brake is applied.
Symptoms
Failed on or not connected — torque converter clutch will not engage at less than one-third throttle. Failed off — torque converter clutch will not disengage when brake is applied.
Diagnostic Trouble Code
536, P1703
Distributor Ignition (DI) System
On gasoline engines, the profile ignition pickup sensor sends a signal to the powertrain control module indicating the engine rpm and the crankshaft (6303) position.
Symptoms
Engine will stall or miss.
Diagnostic Trouble Codes
211, P0340, P0341, P0344
Camshaft Position (CMP) Sensor — 7.3L DI Diesel Only
On the 7.3L DI diesel engines, the CMP sensor provides engine rpm information to the PCM. This rpm input is used to determine shift scheduling and EPC pressure.
Symptoms
No start
Diagnostic Trouble Codes
P0340, P0341, P0344
Air Conditioning (A/C) Clutch 2884
The air conditioning clutch is an electromagnetic clutch that is energized when the clutch cycling A/C pressure cut-off switch (19D594) closes. The A/C pressure cut-off switch is located on the suction accumulator-drier. The closing of the A/C pressure cut-off switch completes the circuit to the clutch and draws it into engagement with the compressor driveshaft. The A/C pressure cut-off switch is used as an input to determine electronic pressure control when the air conditioning clutch is engaged to compensate for the additional load on the engine.
Symptoms
Failed on — electronic pressure control slightly low with A/C off. Failed off — electronic pressure control slightly high with A/C on.
Diagnostic Trouble Codes
539, P1460, P1463, P1464
Mass Air Flow (MAF) Sensor 12B579
The mass air flow sensor (MAF sensor) (12B579) directly measures the mass of air flowing into the engine. The sensor output is a DC (analog) signal ranging from 0.5 volt to 5 volts, used by the processor to calculate injector pulse width. Used as an input to determine electronic pressure control.
Symptoms
High electronic pressure, firm shifts and engagements.
Diagnostic Trouble Codes
157, 158, 159, 184, 185, P0102, P0103, P1100, P1101
Barometric Pressure (BARO) Sensor — 7.3L DI Diesel Only
The barometric pressure sensor (BARO sensor) (12A644) operates similarly to the manifold absolute pressure sensor. It measures barometric pressure instead of intake manifold pressure. The powertrain control module uses the signal from the barometric pressure sensor to determine the altitude at which the vehicle is operating. The powertrain control module then adjusts the E4OD shift schedule and EPC pressure for the altitude.
Symptoms
Firm shift feel, late shifts at altitude
Diagnostic Trouble Codes
P0107, P0108