One of our members, Leonardo Luercho in Argentina, dealt with a 62TE in a Dodge Journey that was in fail-safe sporting codes:
P076A: Direct Clutch Solenoid Circuit Fault
P084B: Direct Clutch Rationality
P1790: Fault Immediately After Shift
P076A seems indicates that there is an electrical problem with the Direct Clutch Solenoid Circuit. But when the description of the code given by the manufacturer is carefully read, it could also mean a performance problem may be the cause.
Here is the explanation due to an electrical cause:
There are six solenoids used to control the friction elements (clutches). The continuity of the solenoid circuits is periodically tested. Each solenoid is turned on or off depending on its current state. An inductive spike should be detected by the PCM during this test. If no spike is detected, the circuit is tested again to verify the failure.
Here is the explanation due to a performance problem:
In addition to the periodic testing, the solenoid circuits are tested if a gear ratio error or pressure switch error occurs. In this case, one failure will result in the appropriate DTC being set. The MIL will illuminate and the transmission goes into neutral, if the DTC is set above 35 km/h (22 mph), Limp-in mode when vehicle speed is below 35 km/h (22 mph).
- When Monitored: Initially at ignition on, then every 10 seconds thereafter. The solenoids will also be tested immediately after a gear ratio error or pressure switch error is detected.
- Set Condition: Three consecutive solenoid continuity test failures, or one failure if test is run in response to a gear ratio error or pressure switch error.
P084B is a gear ratio error code as “rationality” means the clutch does not seem to respond appropriately to the command given by the computer. This makes P084B a companion code to P076A.
P084B is defined by the manufacturer as follows:
The Transmission system uses five pressure switches to monitor the fluid pressure in the LR, 2/4, OD, LC and DC elements. The pressure switches are continuously monitored for the correct states in each gear. The DC pressure switch monitors the fluid pressure to the DC clutch to confirm proper operation of the DC solenoid. If the DC pressure switch is identified as closed in P or N, the code will immediately be set and normal operation will be allowed for that given key start. If the problem is identified for three successive ignition cycles, the transmission will go into Limp-in mode.
- When Monitored: Whenever the engine is running.
- Set Condition: The DTC is set if one of the pressure switches are open or closed at the wrong time in a given gear. If the problem is identified for three successive key starts, the transmission will go into Limp-in mode and the MIL will turn on after 10 seconds of vehicle operation.
P1790 confirms that a gear ratio problem is indeed the most likely cause to the problem.
Theory of Operation
This DTC is not stored alone. It is stored if a Gear Ratio DTC is detected immediately after shift. The existence of DTC P1790 indicates a mechanical or hydraulic (not electrical) related problem. It should be noted, however, that all mechanical problems don't necessarily result in DTC P1790. When this DTC exists, diagnosing the system should be based on the associated DTC and only mechanical causes should be considered.
- When Monitored: After a Gear Ratio Error code is stored.
- Set Condition: After a Gear Ratio Error DTC has already been set. The DTC is set if the fault happened within 1.3 seconds of a shift. The DTC set time will vary from 1.214 seconds to 15 seconds.
The cause to Leonardo’s problem with this Journey is a cracked Direct Clutch Piston as seen in figure 1. This is not the first time ATSG has seen this or Leonardo. In fact he has seen this at least four other times. We have received this call on our help lines a number of times as well. When we do, the tech begins the call by saying: I have changed the solenoid pack and inspected the wiring and everything is perfect. This is quite understandable as code P076A would send you off into checking the electrical first. Especially since this is much easier to fix than pulling the unit out. But when codes P084B and P1790 are present, all three together point to the inside of the transmission.
Could it be the valve body you may ask? It could but we have not seen a replacement valve body fix this concern. If it ever did, we would suspect a leaking bore plug for the Direct Clutch Switch Valve sometimes called the Blocker Valve (figure 2).
Need to pick up our ATSG 62TE Technical Manual? Check it out here!
If you found this article to be helpful, let us know below. If you need technical help from one of our tech experts, give us a call at 1-800-245-7722 and we will be more than happy to assist in getting that job done and the customer out the door!
Are you an ATSG Member yet? If not, click here and become one today!