OBD-II Code
P0966
Severity
Not yet reviewed
Nobody on our side has assessed this code yet, so we are not going to guess at how serious it is.
Can you drive it
We cannot say
Treat it as unknown until a shop reads it with live data. If the check-engine light is FLASHING, stop driving as soon as it is safe to — that means an active misfire, whatever the code.
Indicative cost (USD)
$300–$1,500
From this code's diagnostic notes. Varies by vehicle, diagnosis, parts, and local labor. This is not a repair quote.
P0966 is the Pressure Control Solenoid B Control Circuit High — TCM commands the driver and reads circuit voltage stuck high (open circuit, no current flowing when current was expected), which means an open in the wiring, an open solenoid winding, a pushed-back pin at the case connector, or a TCM driver that's gone open.
How a shop works this
Work from evidence to part, not the other way round. A code names a circuit or a symptom; it does not name the part that failed.
Note every code that is set, not just this one.
Codes that appear together usually narrow the cause faster than any one of them read alone.
Read the freeze frame — the conditions the fault was recorded under.
Cold or warm, idle or load, road speed and engine speed. A fault that only appears cold is a different fault from one that only appears under load, even with the same code on the scanner.
Confirm the fault is current rather than history.
Clear the code and see whether it returns under those same conditions. A code that does not come back may have been logged during a repair, a flat battery, or a bad connection that has since been disturbed.
Then follow the diagnostic notes further down this page, in the order they are written.
They are written in the order a shop works this code, cheapest checks first. Where they name a component, inspect its wiring and connector before replacing it.
If the code comes back after a repair, the underlying fault is still there. That is the point to bring in a scanner with live data and freeze-frame, or a shop that has one.
Common symptoms
- Check engine light
Read the full diagnostic procedureP0966 is the Pressure Control Solenoid B Control Circuit High — TCM commands the driver and reads circuit voltage stuck high (open circuit, no curren…
P0966 is the Pressure Control Solenoid B Control Circuit High — TCM commands the driver and reads circuit voltage stuck high (open circuit, no current flowing when current was expected), which means an open in the wiring, an open solenoid winding, a pushed-back pin at the case connector, or a TCM driver that's gone open.
Cheapest-first
- check the case connector itself before doing anything else — pushed-back terminals from prior repairs and corroded pins from ATF migration are the #1 root cause and cost nothing to find.
- With the connector unplugged, ohm the PCS-B solenoid pin-pair at the case side; healthy spec is 8-30 ohms cold (3-7 ohms GM force-motor, 4-6 ohms Chrysler/Toyota PWM linear, 5-12 ohms Aisin).
- Infinite ohms = open winding, replace solenoid (or pack).
- In-spec resistance at the case = the open is upstream — back-probe the harness between TCM and case connector and ohm each leg end-to-end; anything over 5 ohms wire-resistance on a short run means a corroded splice or pin.
- Check ohms-to-ground on each pin too (>100k ohms expected on a floating circuit).
- Active current at full command should be 0.5-1.5 A — read zero current with the driver commanded on and the open is confirmed.
- Expensive-misdiagnosis caveat: on Chrysler 545RFE/68RFE the integrated solenoid pack frequently sets P0966 when a single internal solder joint inside the pack opens up from thermal cycling — externally everything looks fine, the pigtail ohms correct on cold cars, but at operating temp the joint opens and the code sets.
- This is not field-repairable; full solenoid-pack replacement is the only fix, and technicians who chase external wiring on this trans frequently come-back the customer 200 miles later when the same code returns hot.
Vehicle-specific patterns1996-2007 GM 4L60E/4L65E throws P0966 from the case-connector pin-fit losing tension after repeated unplugging during routine service — GM bulletin g…
- 1996-2007GM 4L60E/4L65E throws P0966 from the case-connector pin-fit losing tension after repeated unplugging during routine service — GM bulletin guidance is to replace the case-connector body, not just the wires, $40-80 part.
- 2003-2010Dodge Ram 1500/2500 with the 545RFE and 2007-up 68RFE shows P0966 routinely in the 70,000-150,000 mile band — the solenoid pack is replaced as a unit per Chrysler service procedure, $500-900 parts plus labor at independents per AAMCO data, $1,000-1,400 at dealers.
- 2007-2013Ram HD with the Aisin AS69RC throws P0966 from a known internal pigtail solder-joint break inside the valve-body solenoid carrier, valve-body R&R required, $800-1,400.
- 2001-2010GM HD with the Allison 1000 (LCT1000) sets the equivalent from a broken wire at the PCS-2 or PCS-3 internal harness flange-chafe location — repair the harness before the solenoid.
Estimated repair$300 to $1,500.
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