Transmission, interlock is executed and does not Move

Hi,

I'm not sure I understand what you are asking. Is there a problem with the shift interlock or is it with the transfer case?

Joe

Hi,

If reverse doesn't work, the first thing I would suggest is to have the computer scanned for diagnostic trouble codes. Either there is an issue with the transmission control module (TCM) which will show up with scanning, or there is a line pressure issue. Interestingly, the one clutch pack that engaged first gear also engages reverse. So I suspect it is something electrical and not hydraulic.

Have the scan done and let me know what codes are found. If there are none, then we will have to check line pressure.

Let me know.
Joe

Hi,

That will provide diagnostic trouble codes for the engine and not the transmission. Do you have access to a scanner that is able to read transmission codes?

Let me know.
Joe

Hi,

I think you may have sent the last message to the wrong person. Let me know.

Joe

Hi,

Yes, those codes are helpful. It seems there is a problem with voltage. Check and confirm all grounds are clean, the battery is fully charged, and there is no corrosion at points of contact.

Next, the codes related to the transmission are specific to a voltage issue. Check the transmission fuse and relay located in the power distribution box under the hood. See pics 1 and 2. I can't be sure, but I suspect the issue is the relay.

Here is a link that explains how to test a relay:

https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit

If you find all connections are good, then we need to check if power is getting to the transmission solenoid assembly. If there isn't, trace power to find loss. If there is power, replace the assembly. The solenoid assembly is located on the back side of the valve body. See pic 3

Let me know what you find.

By the way, these two codes are not related to the transmission.

1388 ASD
1491 Cooling fan circuit

Joe