OBD-II Code P0976 — What It Means & How to Fix It

What Does This Error Mean?

P0976 means Shift Solenoid B Control Circuit is Low. The TCM has detected lower voltage than expected on the solenoid B control circuit. This points to a short to ground in the wiring or a shorted solenoid B coil. Solenoid B controls specific gear combinations — a circuit fault causes those gears to be unavailable. You may notice the transmission stuck in one gear, skipping gears, or entering limp mode.

Affected Models

All automatic transmission vehicles 1996 and newer
Common in GM vehicles with 4L60E and 6L80 transmissions
Common in Ford 4R70W and 5R55 series transmissions
Common in Toyota A340 and A760 series transmissions

Common Causes

Shorted shift solenoid B coil producing a low-resistance path to ground
Short to ground on the solenoid B control wire in the external harness
Moisture or fluid ingress at the external transmission harness connector
Damaged internal harness with a wire contacting the transmission case
Faulty TCM output driver for the solenoid B channel

How to Fix It

Disconnect the external transmission harness connector. Measure resistance between the solenoid B control wire and chassis ground.

Near-zero resistance confirms a short to ground. Anything under 5 ohms on the control wire should be investigated.
With the external connector disconnected, check if the short is in the external harness (between TCM and transmission) or internal (inside the transmission).

If the short disappears when the external connector is disconnected at the TCM, the fault is in the harness between the two. If it persists, the fault is in the TCM.
If the short is inside the transmission, drop the pan and inspect the internal harness for wires with damaged insulation touching the case.

Pay special attention to where the internal harness routes past sharp edges on the valve body or transmission case.
Test solenoid B directly by disconnecting it from the internal harness. Measure resistance across the solenoid terminals. Replace if near zero ohms.

A healthy solenoid B typically reads 10 to 30 ohms. A shorted coil reads close to zero.
Repair wiring or replace the solenoid. Install a new filter and fresh ATF. Clear codes and test drive to confirm normal shifting in all gears.

Monitor shift solenoid B activation via scan tool live data during the test drive.

When to Call a Professional

Solenoid B replacement with fluid and filter service costs $250 to $550. Internal harness replacement is $100 to $300. External harness repair runs $150 to $400. TCM replacement if needed costs $400 to $800 plus programming.

Frequently Asked Questions

What gears does solenoid B control?

The specific gears controlled by solenoid B depend on the transmission model. In a 4L60E, solenoid B is active in 1st and 2nd gear. In other transmission families the pattern differs. A fault in solenoid B typically prevents engagement of the gears it controls.

Can I drive with P0976?

Short distances may be possible if the car is not fully in limp mode. However, a shorted solenoid can cause clutch pack damage over time. Get it diagnosed quickly to avoid escalating repair costs.

How is P0976 different from P0755?

P0755 is a functional fault code — solenoid B has a malfunction. P0976 is an electrical diagnosis code — the solenoid B control circuit is specifically shorted low. P0976 gives you more specific information about the type of electrical fault present.