p0966 code, 2014-5500

[endoscott]

My nephew hauls hay with a 5500, 150,000 miles, Aisin trans, lately has been getting p0966 code and it will hiccup and go into limp mode. Happens more often in colder, wet weather. He dropped the pan and will change filter and fluid and he is thinking it could be a failing bypass solenoid or something. I am OK taking apart a manual trans but I never worked on automatics. Any ideas out there?

 

[R.Taylor]

Pressure Control Solenoid failing.... Easy fix, It's right there under the pan.

 

[sag2]

Check the trans connector below about where the driver sits. It is along the frame rail and can get moisture where it is located. Might have to pull the bottom of the inner fender to get better access. Also look for pin push out in the connector.

 

[Wiredawg]

Friend,

I tried cutting and pasting from FCA Service Manual for 20 minutes, but couldn't get it to work. I highly recommend buying it if you plan to work on your truck... Doesn't come in book form any more. The troubleshooting as WAY more involved than what your NEPHEW is trying to do.

Here's what comes up:

Theory of Operation
The purpose of the diagnostic is to check linear solenoid number 1 circuit for electrical failures by continuously monitoring the solenoid output circuit feedback current for high, low, or open conditions. The TCM controls each linear solenoid via pulse-width modulation for precise control of the hydraulic circuit pressure. If the monitored linear solenoid number 1 output circuit feedback current is greater than or equal to a calibrated high threshold (circuit high) or is less than or equal to a calibrated low threshold (circuit low or open) for a calibrated amount of time, a DTC will be set.



NOTE: Although the name for this DTC indicates it is for Pressure Control Solenoid 2 (B), this DTC actually sets for Pressure Control Solenoid 1.
2
No
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  • 8

3
No

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  • 4

No

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  • 5

6
No

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  • 7

7.CHECK RELATED HARNESS CONNECTIONS

1. Disconnect all TCM harness connectors.
2. Disconnect all related in-line harness connections (if equipped).
3. Disconnect the related component harness connectors.
4. Inspect harness connectors, component connectors, and all male and female terminals for the following conditions:

• 
  
  
  • Proper connector installation.
  • Damaged connector locks.
  • Corrosion.
  • Other signs of water intrusion.
  • Weather seal damage (if equipped).
  • Bent terminals.
  • Overheating due to a poor connection (terminal may be discolored due to excessive current draw).
  • Terminals that have been pushed back into the connector cavity.
  • Perform a terminal drag test on each connector terminal to verify proper terminal tension.

Repair any conditions that are found.


5. Reconnect all TCM harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
6. Reconnect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
7. Reconnect all related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
8. With the scan tool, erase DTCs.
9. Using the recorded Event and Environmental Data, along with the When Monitored and Set Conditions above, operate the vehicle in the conditions that set the DTC.
10. With the scan tool, read TCM DTCs.


Did the DTC return?

Yes

• 
  
  
  • Replace the Transmission Control Module (TCM) in accordance with the Service information. (Refer to 08 - Electrical/8E - Electronic Control Modules/MODULE, Transmission Control/Removal) .
  • Perform the TRANSMISSION VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Transmission Control (TCM) /Standard Procedure).

No

• 
  
  
  • Perform the TRANSMISSION VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Transmission Control (TCM) /Standard Procedure).
  • Test complete.

8.CHECK WIRING AND CONNECTORS

1. The conditions necessary to set the DTC are not present at this time.
2. Using the schematics as a guide, inspect the wiring and connectors specific to this circuit.
3. Wiggle the wires while checking for shorted and open circuits.
4. Check for any Service Bulletins that may apply.


Were any problems found?

Yes

• 
  
  
  • Repair as necessary.
  • Perform the TRANSMISSION VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Transmission Control (TCM) /Standard Procedure).

No

• 
  
  
  • Test complete.

Cheers, Ron​

 

[endoscott]

Thanks! You guys are awesome!