How is this different from P0748, which is also an electrical fault?

P0748 is a general electrical complaint about the solenoid A circuit — it covers opens, shorts and resistance that has drifted out of specification, and different manufacturers set it under different conditions. The 'Control Circuit' codes are narrower and come from a different place: they are the module's own intelligent output driver reporting exactly which fault type it detected. P0960 specifically means open load. That precision is useful, because it lets you skip straight to continuity and coil resistance rather than working through every electrical possibility.

The freeze frame shows the car was parked. Does the fault only happen at a standstill?

No, and reading it that way will waste your time. The module's driver detects an open load by pushing a tiny bias current through the solenoid even when it is commanded off, so it can find a missing connection with the ignition on and the engine not running. Codes of this type are routinely captured in a parked, cold car before anything has been asked of the transmission. The stationary freeze frame is a property of how the test works, not a description of when the fault appears.

Why can I not just test it with a multimeter while it is running?

Because the circuit is not a simple on-or-off one. Line pressure solenoids are variable-force devices driven by pulse-width modulation under closed-loop current control, so the voltage on the driver wire is a square wave whose duty cycle changes constantly. An averaging meter placed across it returns a number that looks plausible whether the circuit is healthy or not. Resistance measurements are valuable, but taken with the circuit dead and the module unplugged. For live checks the right tools are a low-current clamp or a scope.

Can I keep driving with P0960?

Only far enough to reach a workshop, and how carefully depends on what the car is doing. An open circuit means the module has no control over line pressure whatsoever, leaving only the transmission's hydraulic default. If the car bangs into gear and shifts harshly, the default is a high pressure and the clutches are being applied firmly rather than slipping — uncomfortable but not immediately destructive. If instead it slips, flares between gears or struggles to pull away, pressure is too low, the clutches are slipping under load, and every mile is generating heat and wear. In that case stop and have it recovered.

OBD-II trouble code

P0960: Pressure Control Solenoid "A" Control Circuit/Open

This one is the module reporting on its own output stage rather than on the transmission's behaviour. It can set with the car standing still and the engine off — and one measurement at the case connector decides whether this is a wiring repair or a solenoid pack.

High severityPowertrainTransmission / Pressure ControlDrivable short-term

Quick facts

System: Powertrain
Category: Transmission / Pressure Control
Severity: High severity
Drivable: Usually safe to drive short-term
Repair cost range: $150 – $1,800
DIY difficulty: Shop recommended

One of 27 pressure control solenoid codes

P0960 sits in a grid: one axis is which solenoid the letter refers to, the other is what went wrong with it. Each cell is a genuinely different fault with its own diagnosis — but codes from the same row or column often appear together, and what a pairing means is usually the fastest way in. The hub page lays out all 27 and explains how to read them against each other.

See all pressure control solenoid codes →

Browse every code in P0900–P0999, or start from the full code library.

What does P0960 mean?

P0960 belongs to a newer style of diagnostic than the pressure control solenoid codes forty numbers below it, and the difference is worth understanding because it changes where the diagnosis starts.

The older codes in the P0745 to P0749 group describe the solenoid's effect: the module commands a line pressure, watches what the transmission does, and complains when the result is wrong. The codes titled 'Control Circuit' are something else. They are a self-report from the module's own output stage. Modern transmission control modules do not simply switch a solenoid on and off through a plain transistor. They use an intelligent driver that measures what it is doing while it does it, and that driver can distinguish an open load, a short to ground and a short to battery on its own, then report which one it found. P0960 is that driver saying it found nothing connected at all.

That produces an immediate practical consequence that surprises people. Open-load detection does not need the solenoid to be energised. The driver pushes a very small bias current through the load even when the solenoid is commanded off, precisely so it can confirm the load is still there. So this code can set with the ignition on and the engine not running, in a parked car, before the transmission has been asked to do anything. If the freeze frame shows zero road speed, zero engine load and a cold transmission, that is not a corrupted record and it is not a clue about a particular manoeuvre — it is the normal way this code is captured. Reading it as 'the fault happens at a standstill' sends people looking for a condition that does not exist.

The second thing that separates this code from a conventional electrical fault is that you cannot judge the circuit with an ordinary multimeter on the driver wire. Line pressure solenoids are variable-force devices driven by pulse-width modulation under closed-loop current control. The voltage on that wire is a square wave whose duty cycle changes continuously, so an averaging meter placed across it returns a number that is genuinely meaningless — it will read something plausible on a healthy circuit and something equally plausible on a faulty one. The instruments that answer the question are a low-current clamp around the driver wire, or a scope. Resistance measurements are still useful, but only with the circuit dead and the module disconnected.

What makes the difference to the bill is where the open turns out to be, and the split is stark. Everything outboard of the transmission case connector — the external harness, the connector body, the module-side terminals — is repairable, and repairing it is a few hundred dollars at most. Everything inboard of it is not. The internal harness terminals and the solenoid's own lead-out sit in fluid that reaches well over 120°C, and they are assembled by welds and moulded carriers rather than by serviceable crimps. An open in there is not repaired; the solenoid or the whole internal harness assembly is replaced, which means dropping the pan, draining the fluid and often disturbing the valve body. Testing at the external case connector — with the module unplugged, checking coil resistance from the case side and continuity back to the module separately — splits those two worlds in about ten minutes and tells the owner which conversation they are having.

As for what the transmission does meanwhile: an open circuit means the module has no control over line pressure at all, only whatever the hydraulic default happens to be. Some designs default to a high pressure and shift brutally; others default low and slip. The first is unpleasant, the second is destructive, and a driver should establish which one they have before deciding how far to drive.

Common causes

Open circuit in the external transmission harness between module and case connector
Terminal backed out of, or corroded within, the case pass-through connector
Broken lead-out or internal weld at the solenoid itself
Damaged internal harness inside the transmission after valve body or pan work
Solenoid coil failed open from age and heat cycling
Chafed harness section worn through where it crosses the case or bellhousing
Module connector terminal damaged, spread or backed out
Failed output driver inside the transmission control module
Connector left unplugged or partially seated after transmission service
Rodent damage to the exposed harness run along the transmission

Symptoms

Transmission dropped into fail-safe or limp mode, often locked in one forward gear
Harsh, slamming engagements and gear changes
Slipping or flaring between gears on designs that default to low pressure
Check engine light on, sometimes with the transmission warning lamp as well
Code present with the ignition on before the vehicle has been driven
No torque converter lock-up and correspondingly poor fuel economy
Reduced top speed because the transmission will not select higher gears
Multiple solenoid circuit codes stored together, pointing at a shared connector
Fault appearing immediately after a transmission service or repair
Rising transmission fluid temperature during sustained driving

Diagnostic steps

1.Read freeze frame but do not over-interpret it — an open-load fault can be detected with the engine off, so a stationary capture is normal for this code rather than significant.
2.Check for other solenoid circuit codes stored alongside it, since several together point at a shared connector or ground rather than at one component.
3.Inspect the external transmission harness and the case pass-through connector for chafe, corrosion and backed-out terminals before any measurement.
4.Disconnect the module and measure coil resistance at the transmission case connector, comparing against the manufacturer's specification.
5.Separately check continuity of each wire from the case connector back to the module connector, which splits an external fault from an internal one.
6.Treat a coil reading of effectively infinite resistance at the case connector as an internal fault, which means solenoid or internal harness replacement rather than a wiring repair.
7.Do not attempt to judge the live circuit with an averaging multimeter, since the driver is pulse-width modulated and the reading will be meaningless.
8.Use a low-current clamp or a scope on the driver wire if live confirmation is needed, watching commanded current against actual current.
9.Inspect and test the module connector terminals for tension before condemning the module itself.
10.Confirm fluid level and condition as part of the repair, since any internal work will require a fill and the fluid's state affects what else should be done.

Repair cost

$150 – $1,800

Diagnosis is $100 to $200, and splitting internal from external at the case connector is quick. An external harness or connector repair is $150 to $450 and is the best outcome. A pressure control solenoid replacement is $150 to $400 for the part with $250 to $600 labour depending on whether the pan alone comes off or the valve body has to come out, so $400 to $1,000 fitted is typical. An internal harness assembly adds $150 to $350. Fluid and filter are $120 to $300 on top. Module replacement and programming, which is uncommon, runs $600 to $1,800.

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DIY vs shop

Leave this one to a qualified shop. It typically involves emissions-critical components, refrigerant handling, or other work that requires manufacturer-grade tooling, training, or certification. DIY attempts often produce a more expensive problem than the original code.