Issue Overview:
- 2000-02 Dodge trucks equipped with the 4.7-liter V-8 and the 45RFE transmission may lose the turbine-shaft signal, resulting in a DTC P0715 and/or slow PRNDL response on the instrument-panel indicator.
- After overhaul, a vehicle with a 45RFE or 545RFE moves forward with the manual shift lever in the neutral position. When reverse is selected, the transmission is bound up.
- Some 2004-2005 Jeep Grand Cherokee and Liberty models with the 545RFE may have misleading DTCs indicating low line pressure and gear-ratio errors.
2000-02 Dodge trucks equipped with the 4.7-liter V-8 and the 45RFE transmission may exhibit a loss of turbine-shaft signal resulting in a DTC P0715 and/or a complaint of slow PRNDL response on the instrument-panel indicator. Note: This problem can be intermittent or happen more frequently when the transmission is hot.
The cause may be a faulty capacitor in the auto-shutdown relay circuit allowing a small short to power on the transmission control module’s main ground circuit at G115 ground location. Note: The capacitor ground strap is installed on top of the TCM grounds at ground location G115. When the capacitor fails, the main TCM grounds will be faulty, which can be checked at terminals 53, 39, 37 and 57 at the TCM. Voltage to ground should be below 0.1 volt. See Figure 1 for a partial TCM wire schematic.
Ground problems typically will show up on terminal 13 at the TCM, which is the internal ground provided for the turbine- and output-shaft speed sensors as well as the transmission-fluid temperature sensor. This terminal has shown readings as high as 1.0 volt. This can cause the signal from the turbine-shaft speed sensor to be erratic or fall off at high shaft speed. There have also been complaints of a slow response in the PRNDL display on the instrument panel because of the main-ground problems.
Figure 2 shows a wiring diagram of the capacitor in the auto-shutdown relay circuit. Notice that the feed to the capacitor is from a 30-amp fuse. The capacitor is used as a noise filter for the injectors and coil-over-plug circuits. The problems listed previously have shown up as the capacitor and its internal diode are failing.
Using the part number provided under service information, replace the capacitor (Figure 3).
Refer to Figure 4 for a view of the new-design capacitor.
Testing: You can test the capacitor by simply disconnecting it to see whether the symptoms disappear. ATSG strongly recommends replacement. Note: ATSG has also had situations where the turbine-shaft speed signal continued to be a problem even after the capacitor was replaced and the harness for the TSS circuit proved good. In these instances the TCM will have to be replaced.
- Capacitor (Dodge part number) . . . . . . . . . . . 56028644AB
After overhaul, the vehicle moves forward with the manual shift lever in the neutral position. When reverse is selected, the transmission is bound up.
The underdrive friction plates are 0.076 inch thick and the overdrive friction plates are 0.091 inch thick (Figure 5).
The internal tooth configuration is identical on both (Figure 6); therefore, they can easily be swapped with one another. When this is done the underdrive clutch is mechanically locked on, resulting in the complaints listed.
Make certain that the thinner underdrive friction plates are stacked in the underdrive-clutch pack (Figure 7).
You also must take care with the steel plates, as the plates for both clutches have the same 12-tooth configuration and an outer diameter of about 5.440 inches. However, the underdrive steel plates are 0.067 inch thick and the overdrive steel plates are 0.086 inch thick. In addition, the reverse-clutch steel plates are the same thickness as the underdrive-clutch steel plates.
Some 2004-2005 Jeep Grand Cherokee and Liberty models may come in with the following diagnostic trouble codes stored in the TCM memory:
- P0868 – Line Pressure Low
- P0731 – Gear-ratio error in 1st
- P0732 – Gear-ratio error in 2nd
- P0733 – Gear-ratio error in 3rd
- P0734 – Gear-ratio error in 4th
- P0735 – Gear-ratio error in 5th
- P0736 – Gear-ratio error in Reverse
- P01736 – Gear-ratio error in 2 prime
The vehicle may have the MIL illuminated and the transmission may be in limp mode. These conditions may be intermittent.
Jeep Grand Cherokee and Liberty models built between April 7, 2004, and Feb. 27, 2005, were equipped with TCMs that have an internal electronic-circuit failure. The suspect TCMs have build dates from April 4, 2004 (Julian date 0954), to Feb. 9, 2005 (Julian date 0405).
Note: The Julian date 0954 translates as follows: 095 is the day of the year that the TCM was built, and 4 is the year; this means the TCM was built on the 95th day of 2004. The Julian dates can be found on the TCM bar-code tag.
Make certain that line pressure is not low and that no friction damage has occurred; repair as necessary.
Replace the TCM and perform the “Quick Learn” procedure, then road-test to ensure proper vehicle operation.
- 2004 Jeep Grand Cherokee transmission control module . . . . . 56044574AC
- 2005 Jeep Liberty transmission control module . . . . . . . . . . . . . 56044737AF
March 2011 Issue
Volume 28, No. 3
- Overview
- Dodge trucks: DTC P0715 and/or slow PRNDL response
- 45RFE/545RFE: Pulls forward in neutral
- Jeep 545RFE: Misleading codes