Dodge 48RE Transmission & The Parts Affected
| Change: Beginning at the start of production for the model year 2005, Dodge trucks equipped with the 5.9 diesel and 48RE transmission, were equipped with an electronically controlled Transmission Throttle Valve Actuator (TTVA), See Figure 1. This Actuator has replaced the previous Throttle Valve Cable, which controls the Throttle Valve in the Valve Body.
Reason: To electronically control of the Throttle Valve inside the valve body |
Parts Affected:
- TRANSMISSION THROTTLE VALVE ACTUATOR – The TTVA consists of an electronic DC motor, which has two potentiometers and a gear driven system that controls the Throttle Valve in the valve body, for shift timing, passing gear below 4th gear and pressure control. The position of the gear train is monitored by the TTVA Position sensor which supplies an input to the Engine Control Module (Figure 2). The TTVA is controlled by the ECM thru the inputs of Accelerator Position Sensor 1 and 2. Refer to the chart in Figure 3 for a comparison chart of APP1 and APP2 to the voltages that control the TTVA and the TTVA position voltage feedback to the ECM. Note: If the TTVA is removed from the transmission, the ECM will have to relearn its “0” position. The ignition will have to be turned on and the engine off for 30 seconds to accomplish “Auto Zero.”
With the addition of the TTVA a new wiring harness was introduced. Refer to Figure 4 for a partial wire schematic of the TTVA and its connectors.
- TRANSMISSION CASE – The transmission case had two bosses added to it to mount the new TTVA.
Transmission Case
Interchangeability:The previous design Transmission Case is not interchangeable with the new design TTVA because of the lack of mounting bosses on the case.
Service Information
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- TTVA TROUBLE CODE DESCRIPTIONS
- P1749 – TTVA Position Sensor Low (Electrical)
- P1750 – TTVA Position Sensor High (Electrical)
- P1751 – TTVA Position Minimum range Performance (Mechanical)
- P1753 – TTVA Position Mechanical Performance (Mechanical)
- P1754 – TTV Actuator Stuck (Electronic/Mechanical)
- P1755 – TTVA Control Circuit (Electronic/Mechanical)
- Note: Some of the DTC’s listed can cause the voltage to the TTVA to be shut off by the ECM, this will in turn cause the motor position to be in high TV mode.
C1 Connector and C2 Connector
Voltage and Percentage Charts
Accelerator Position Sensor Closed Throttle Wide Open Throttle Accelerator Position Sensor 1% 2 96 Accelerator Position Sensor 1 Voltage .45 V 4.56V Accelerator Position Sensor 2% 3 97 Accelerator Position Sensor 2 Voltage .24 V 2.29 V
TRANSMISSION THROTTLE VALVE – ACTUATOR PARTIAL ELECTRICAL SCHEMATIC
ENGINE CONTROL MODULE
Located on the front drivers side of engine