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Posting for a friend.
Believe truck is a 2005. It is a Dodge Ram 1500 with greater than 100K miles on it. Transmission is 45 RFESymptoms.
Put truck into reverse and felt like went to neutral. Did the same thing, put in drive and felt like went to Neutral.
Pushed truck back to curve, tried later in day began to drive and truck drove. then went back to neutral in short distance.Codes are
P0876
P0731
P0841I understand these to have faulty solenoids but do not have experience testing. Any experienced suggestions would be appreciated.
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1) Check the fuses to make sure one isn’t blown. The power circuitry to the solenoids is fuse protected. 2) Check level, color, and condition of trans fluid.
I mentioned to him already to check fuses due to the multiple codes and to check fluid condition, level as good start to any transmission problem.
I guess my question is any one familiar with a particular solenoid to start testing and good testing techniques. I have seen some of the videos on testing the 2/3 or OD solenoids etc but isn’t that usually a shifting problem. I do not know why he would loose all forward/ reverse ability but don’t want to blame failed transmission without evidence.
I mentioned to him already to check fuses due to the multiple codes and to check fluid condition, level as good start to any transmission problem.
Checking fuses is the most important first step when there is a fault like this involving more than one component on an electronically controlled unit, such as this transmission. The reasoning behind this is, they aren’t going to fail at the exact same moment. You’d be surprised how many times someone thinks they will have to replace an engine, transmission, or very expensive control module, and it turns out to be a blown fuse or loose wire. The fluid condition is another way to quickly assess the probable mechanical condition of the unit. If the fluid is dark, burnt smelling, and/or has glittery bits in it, there is a higher likelihood of catastrophic failure. If, on the other hand, the fluid looks and smells pristine, there is a higher likelihood the transmission is ok and there is perhaps a simpler reason for the issue. The basics must be checked before further diagnosis is warranted and before doom and gloom are being considered. There is no shop or diagnostician anywhere who would even presume to guess what might be wrong with this transmission until the fuses and fluid has been checked.
I guess my question is any one familiar with a particular solenoid to start testing and good testing techniques.
As for solenoid testing techniques, it is the same regardless of what kind of solenoid or where it is located; engine, transmission, emissions, etc. All the same. Check at each solenoid’s electrical connector for the presence of power and ground when it is supposed to be energized (on). Check the resistance of the solenoid coil, should be very low: usually between 0.2 and 0.8 ohms. If those tests check out, attempt to manually activate the solenoid by directly applying power and ground to it, and it should click and/or you should see its action occur.
I do not know why he would loose all forward/ reverse ability
This is an electronically controlled hydraulically operated device. There are fluid pressure sensors that report to the transmission control module (transmission computer) and solenoid valves that open and close to switch hydraulic circuits that the fluid flows through to govern its operation. When the electronics fail, the fluid isn’t being monitored and/or flowing through the proper circuits, so the transmission malfunctions. But, mechanical failures can happen too. The fluid is circulated and pressurized by the internal fluid pumps and orifices in the case and valve body. Fractures in the case or valve body can result in loss of hydraulic pressure in a circuit, and thus malfunctions occur.
but don’t want to blame failed transmission without evidence
Exactly. The fuse and fluid test help us determine which direction to start troubleshooting, they don’t tell us necessarily what is wrong, just a place to start. For example, it makes no sense to troubleshoot electrically if there is trash and bits of metal swimming in burnt fluid. It also makes no sense to troubleshoot mechanically when there is a blown fuse, loose connector, or damaged wire. We have to start somewhere, these tests provide a starting point. In your specific case, the codes reported belong to multiple components. The odds are astronomical that they all failed simultaneously. This points to a common cause of failure. Either they have all stopped getting power, or there has been a major mechanical failure such that they have been rendered ineffectual. The part where you said at one point it began operating again, then shortly soon after quit operating, leads me to believe an electrical failure, but mechanical cannot yet be ruled out without doing the basic checks.
Thanks Cap for detailed reply. All makes since. I have only been able to talk with him via text to this point. I will let you guys know what is found out if I get further personally involved.
“As for solenoid testing techniques, it is the same regardless of what kind of solenoid or where it is located; engine, transmission, emissions, etc. All the same. Check at each solenoid’s electrical connector for the presence of power and ground when it is supposed to be energized (on). Check the resistance of the solenoid coil, should be very low: usually between 0.2 and 0.8 ohms. If those tests check out, attempt to manually activate the solenoid by directly applying power and ground to it, and it should click and/or you should see its action occur.”
Any advice for testing procedure on Transmission pressure sensor and Output speed sensor.
I came across an interesting TSB today. There is a spin-on filter, similar to an engine oil filter, inside the transmission pan. This filter can rupture and hydraulic pressure lost causing the engagement issues and codes. TSB 21-007-06
Fixed.
Turned out to be loose screw on filter. Could spin it with 1 finger. Glad not to throw parts at that.
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