Shift Pointers
- Author: Wayne Colonna
- Subject Matter: ’01 Dodge 2500 5.9L diesel, 47RE
- Issue: Bumps clear at 60 mph
Problem began immediately after an engine oil change
A 2001 Dodge 2500 5.9L diesel with a 47RE transmission comes in to Donald Holliday’s Covington Automotive shop with intermittent and erratic bumps that seem to clear up once the vehicle has reached 60 mph or greater. The technician driving the vehicle notices that the converter clutch is being commanded on and off when the bumps are felt. The way the converter clutch was being commanded on and off was not occurring in the typical fashion these vehicles are notorious for. Usually, the shuttle is more rhythmic between 45-50 mph. The convert clutch in this case was more “out/off” then quickly back “in/on” maybe once or twice then stop before intermittently repeating itself.
When it comes to TCC shuttle, vehicles using the RE transmission (42, 44, 46, 47 and 48), there is a healthy list of possibilities which can vary depending on it being equipped with a gas, 12-valve or 24-valve diesel engine. This vehicle had the 5.9L diesel with a 47RE transmission. The customer mentioned that this problem began immediately after an engine oil change.
The tech decided to look around where the filter was.
He saw that the A/C high-pressure switch was on the discharge line near the compressor as well as being close to the filter. He unplugged it and noticed oil was in the connector. He drove the vehicle with the pressure switch unplugged and the complaint was no longer evident.
In this case the connector was cleaned to remedy the complaint as the switch was still functional.
Note: The A/C high-pressure switch is connected in series electrically with the low-pressure switch and the heater control, between ground and the PCM (Figure 1). This means the low-pressure switch (mounted on the top of the accumulator) could also become suspect.
Unplugging one or the other of these switches is a quick test to see if it corrects a TCC shuttle condition. If it does, each switch will need to be tested to know which one has failed and will need to be replaced.
It is just one more reason to add to your already lengthy list of reasons for a Dodge to do the “TCC Shuttle.”
