Dodge Ram Truck 1500-2500-3500. Manual — part 1744

P1753-TRANSMISSION THROTTLE VALVE MECHANICAL PERFORMANCE (CONTINUED)

2.

CHECK TTVA FOR SIGNS OF DAMAGE

Turn the ignition off to the lock position.

Visually inspect the TTVA shaft for any signs of external damage or improperly mounted.

NOTE: It is not necessary to remove the TTVA to perform this procedure.

Is the TTVA damaged or improperly mounted?

Yes

>> Repair as necessary.

Perform RE TRANSMISSION VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/
ELECTRONIC CONTROL MODULES/TRANSMISSION CONTROL MODULE - DIAGNOSIS AND TEST-
ING)

No

>> Go To 3

3.

CHECK IF TTVA SHAFT END IS DAMAGED

Turn the ignition off to the lock position.

Remove the TTVA from the transmission per the Service Information. (Refer to 21 - TRANSMISSION/TRANSAXLE/
AUTOMATIC - 48RE/THROTTLE VALVE ACTUATOR - REMOVAL)

Inspect the end of the TTVA shaft for cracks or damage.

NOTE: The end of the TTVA should be keyed or ”D” shaped and fit tightly over the Throttle Valve shaft.

Is the end of the TTVA shaft undamaged and fit tightly over the Throttle Valve shaft?

Yes

>> Go To 4

No

>> Inspect the Throttle Valve shaft on the transmission for free movement. If the Throttle valve does not

move freely, inspect internal transmission components related to the Throttle Valve and replace as nec-
essary. Replace the TTVA in either case. Refer to the Service Information. (Refer to 21 - TRANSMIS-
SION/TRANSAXLE/AUTOMATIC - 48RE/THROTTLE VALVE ACTUATOR - REMOVAL)

Perform RE TRANSMISSION VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/
ELECTRONIC CONTROL MODULES/TRANSMISSION CONTROL MODULE - DIAGNOSIS AND TEST-
ING)

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AUTOMATIC TRANSMISSION - 48RE - DIESEL - ELECTRICAL DIAGNOSTICS

DR/DH

P1753-TRANSMISSION THROTTLE VALVE MECHANICAL PERFORMANCE (CONTINUED)

4.

CHECK THE TRANSMISSION THROTTLE VALVE ACTUATOR

Properly support the TTVA to where the end of the shaft can be observed and reconnect the TTVA wiring harness.

NOTE: Each time the ignition is cycled to the on position, the ECM commands a TTVA internal calibration
procedure (autozero) to determine the zero position. Do not press on the accelerator pedal during this test.
Ignition on, engine not running.

Observe the output shaft of the TTVA during the autozero procedure.

After completion of the autozero procedure, while observing the TTVA shaft, press the accelerator pedal to full throt-
tle.

Does the TTVA internal motor move the TTVA shaft?

Yes

>> Inspect the Throttle Valve shaft on the transmission for free movement. If the Throttle valve does not

move freely, inspect internal transmission components related to the Throttle Valve and repair or replace
as necessary. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - 48RE/THROTTLE VALVE
ACTUATOR - REMOVAL)

Perform RE TRANSMISSION VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/
ELECTRONIC CONTROL MODULES/TRANSMISSION CONTROL MODULE - DIAGNOSIS AND TEST-
ING)

No

>> Replace the TTVA per the Service Information.

Perform RE TRANSMISSION VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/
ELECTRONIC CONTROL MODULES/TRANSMISSION CONTROL MODULE - DIAGNOSIS AND TEST-
ING)

5.

INTERMITTENT WIRING AND CONNECTORS

The conditions necessary to set this DTC are not present at this time.

Using the schematics as a guide, visually inspect the related wiring harness. Look for any chafed, pierced, pinched,
or partially broken wires.

Visually inspect the related wiring harness connectors. Look for broken, bent, pushed out, or corroded terminals.

Wiggle the wiring and connectors while checking for any possible open or shorted circuits.

Check for any Service Information Tune-ups or Technical Service Bulletins that may apply.

Were there any problems found?

Yes

>> Repair as necessary.

Perform RE TRANSMISSION VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/
ELECTRONIC CONTROL MODULES/TRANSMISSION CONTROL MODULE - DIAGNOSIS AND TEST-
ING)

No

>> Test Complete.

DR/DH

AUTOMATIC TRANSMISSION - 48RE - DIESEL - ELECTRICAL DIAGNOSTICS

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P1754-TRANSMISSION THROTTLE VALVE ACTUATOR STUCK

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AUTOMATIC TRANSMISSION - 48RE - DIESEL - ELECTRICAL DIAGNOSTICS

DR/DH

P1754-TRANSMISSION THROTTLE VALVE ACTUATOR STUCK (CONTINUED)

For the Transmission circuit diagram (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - 48RE - SCHE-
MATICS AND DIAGRAMS)

For a complete wiring diagramRefer to Section 8W

Theory of Operation

The transmission throttle valve cable has been replace by the transmission throttle valve actuator (TTVA). The TTVA
consists of an electric DC motor, two potentiometers, and a gear drive system. The TTVA is mechanically connected
to the transmission throttle valve in the valve body by the “D” shaped opening in the bottom of the TTVA shaft.

The Transmission Throttle Valve Actuator (TTVA) does not require any mechanical adjustments. All changes in throt-
tle valve position are controlled by the Engine Control Module (ECM).

The TTVA does require an initialization period after the actuator has been removed or replaced. After the actuator
has been removed or replaced, move the ignition to the ON position for thirty (30) seconds. This will allow the ECM
sufficient time to perform the internal calibration procedures to learn the TTVA’s current “zero” position.

•

When Monitored:
Continuously with the ignition on.

•

Set Condition:
The monitored TTVA position sensor does not indicate a change in position when the TTVA is commanded to
change the position.

Possible Causes

(F856) 5 VOLT SUPPLY CIRCUIT OPEN

(K314) TTVA MOTOR (+) CIRCUIT OPEN

(K315) TTVA MOTOR (-) CIRCUIT OPEN

(K314) TTVA MOTOR (+) CIRCUIT SHORT TO GROUND

(K315) TTVA MOTOR (-) CIRCUIT SHORT TO GROUND

(K314) TTVA MOTOR (+) CIRCUIT SHORT TO VOLTAGE

(K315) TTVA MOTOR (-) CIRCUIT SHORT TO VOLTAGE

(K314) TTVA MOTOR (+) CIRCUIT SHORT TO ANOTHER CIRCUIT

(K315) TTVA MOTOR (-) CIRCUIT SHORT TO ANOTHER CIRCUIT

TRANSMISSION THROTTLE VALVE COMPONENTS

TRANSMISSION THROTTLE VALVE ACTUATOR

ENGINE CONTROL MODULE

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 21 - TRANSMIS-
SION/TRANSAXLE/AUTOMATIC - 48RE - STANDARD PROCEDURE)

DR/DH

AUTOMATIC TRANSMISSION - 48RE - DIESEL - ELECTRICAL DIAGNOSTICS

21 - 911