Section 07-01: Transmission, Automatic, E4OD
1997 F-250 Heavy Duty, F-350 and F-Super Duty Workshop Manual
DESCRIPTION AND OPERATION

Transmission Electronic Control System

 

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





ItemPart NumberDescription
1MAP/BARO Sensor
29B989Throttle Position Sensor
3Engine Oil Temperature (EOT) Sensor (7.3L DI Diesel)
4Intake Air Temperature (IAT) Sensor (7.3L DI Diesel)
5Transmission Control Switch (TCS) and Transmission Control Indicator Lamp (TCIL)
612A650Powertrain Control Module
7Transmission Solenoid Body
84x4 Low (4x4 L)
99E731Vehicle Speed Sensor (VSS) (Model-Dependent)
107A247Transmission Range (TR) Sensor
11Accelerator Pedal (AP) Sensor (7.3L DI Diesel)
12Programmable Speedometer/Odometer Module (PSOM)
1313480Stoplight Switch
14Electronic Ignition (EI) System
15Distributor Ignition (DI) (Gasoline Engine)
16Camshaft Position (CMP) Sensor (7.3L DI Diesel)
172884Air Conditioning (A/C) Clutch
1812B579Mass Air Flow Sensor
19Barometric Pressure (BARO) Sensor (7.3L DI Diesel)

 

Manifold Absolute Pressure (MAP) Sensor — Gasoline Engines



Description

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



Description

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)



Description

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



Description

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



Description

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.



Description

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



Description

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)



Description

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



Description

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



Symptoms

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



Symptoms

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



Description

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



Description

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



Description

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



Description

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)



Description

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



Description

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



Description

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



Description

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



Description

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



Description

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



Description

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