P0773 Shift Solenoid "E" Electrical Malfunction

The P0773 trouble code is an OBD-II diagnostic trouble code related to the electrical control of Shift Solenoid "E" inside an automatic transmission.

P0773 – Shift Solenoid "E" Electrical Malfunction

This code means that the Transmission Control Module (TCM) has detected an electrical problem in the circuit controlling Shift Solenoid "E".

Shift Solenoid "E" is an electronically controlled valve that directs transmission fluid through specific hydraulic passages. The TCM uses this solenoid, together with other shift solenoids, to control gear changes.

Because P0773 specifically identifies an electrical malfunction, the first diagnostic focus should be on the solenoid, wiring, connectors, power supply and TCM control circuit rather than immediately assuming there is internal transmission damage.

What Does P0773 Mean?

Automatic transmissions use hydraulic pressure to engage clutches and control different gears.

The TCM controls this hydraulic system electronically through shift solenoids.

The basic process is:

TCM → Electrical Signal → Shift Solenoid "E" → Hydraulic Fluid Flow → Transmission Gear

When the TCM detects that the electrical circuit for Solenoid "E" does not behave as expected, it stores:

P0773 – Shift Solenoid "E" Electrical Malfunction

Depending on the vehicle, the TCM may monitor:

• Solenoid resistance

• Circuit continuity

• Current flow

• Voltage

• Short-to-ground conditions

• Short-to-power conditions

• Open-circuit conditions

• Solenoid response

What Is Shift Solenoid "E"?

Shift Solenoid "E" is a small electrically controlled valve used inside an automatic transmission.

When the TCM sends an electrical command, the solenoid changes the flow of transmission fluid through the hydraulic system.

The exact function of Solenoid "E" varies between transmissions.

It may be involved in controlling:

• Gear changes

• Clutch application

• Brake application

• Shift valves

• Hydraulic circuits

Therefore, P0773 does not identify a specific gear by itself.

The transmission manufacturer's service information is required to determine exactly what Solenoid "E" controls.

What Does "Electrical Malfunction" Mean?

The word electrical is important in P0773.

The TCM is detecting an abnormal electrical condition rather than simply detecting that the transmission is shifting poorly.

Possible electrical problems include:

• Open circuit

• Short circuit

• Short to ground

• Short to power

• Excessive resistance

• Low current

• High current

• Failed solenoid coil

• Damaged wiring

• Corroded connector

• Loose terminal

• TCM driver problem

This is different from P0771, P0772 and P0774, which indicate performance/stuck-off, stuck-on and intermittent conditions respectively.

Symptoms of P0773

Possible symptoms include:

• Check Engine Light

• Transmission warning light

• Harsh shifting

• Delayed shifting

• Erratic shifting

• Missing gear

• Transmission stuck in one gear

• Unexpected downshifting

• Transmission slipping

• Reduced acceleration

• Limp mode

• Delayed Drive engagement

• Delayed Reverse engagement

• Poor fuel economy

In some vehicles, the only obvious symptom may be the warning light.

What Does P0773 Feel Like While Driving?

The driving behavior depends on what Solenoid "E" controls in the particular transmission.

Harsh gear changes

If the solenoid cannot operate correctly, hydraulic pressure may not be controlled at the correct moment.

Delayed shifting

The transmission may hesitate before completing a gear change.

Missing gear

A particular gear may not engage correctly.

Transmission stuck in one gear

The TCM may disable certain shifts to protect the transmission.

Limp mode

The vehicle may operate with a limited number of gears.

Slipping

If the affected hydraulic circuit controls a clutch, incorrect operation can result in clutch slip.

Common Causes of P0773

Faulty Shift Solenoid "E"

The internal electromagnetic coil may be open, shorted or have abnormal resistance.

Open circuit

A broken wire can prevent current from reaching the solenoid.

Short circuit

A damaged wire can contact another circuit or ground.

Damaged wiring harness

Heat, vibration, transmission-fluid contamination and mechanical movement can damage the harness.

Corroded connector

Corrosion can increase resistance and interfere with the electrical signal.

Loose connector terminal

A terminal that does not make reliable contact can cause an electrical malfunction.

Damaged solenoid connector

The connector itself may be cracked, damaged or contaminated.

Low system voltage

A weak battery or charging problem can affect transmission control.

Blown fuse

Some transmission solenoid circuits receive power through a shared fuse.

Poor ground

A poor electrical ground can interfere with solenoid operation.

Transmission internal wiring problem

The wiring inside the transmission can also fail.

TCM driver failure

The TCM contains electronic drivers that control the solenoids. A failed driver can cause P0773.

Is P0773 Serious?

P0773 should be taken seriously, but it does not automatically mean that the transmission is mechanically damaged.

Because this is primarily an electrical code, the actual repair may be relatively simple if the cause is:

• A damaged wire

• Corroded connector

• Loose terminal

• Blown fuse

• Faulty solenoid

However, continued driving with incorrect shifting can create additional transmission wear.

Can You Drive With P0773?

If the vehicle shifts normally and there are no other symptoms, a short drive to a repair facility may be possible.

Avoid continued driving if the vehicle has:

• Severe slipping

• Violent shifting

• Loss of gears

• Transmission overheating

• Limp mode

• Loss of Drive or Reverse

P0773 vs. P0774

These two codes both concern Shift Solenoid "E", but they indicate different conditions.

P0773 – Shift Solenoid "E" Electrical Malfunction

The TCM detects an electrical problem in the solenoid circuit.

P0774 – Shift Solenoid "E" Intermittent

The electrical or operational problem occurs intermittently.

If P0773 is present, the electrical circuit should be tested carefully.

P0773 vs. P0772

P0772 – Shift Solenoid "E" Stuck On

The system detects that Solenoid "E" is stuck in an active condition.

P0773 – Shift Solenoid "E" Electrical Malfunction

The system detects an electrical problem involving the solenoid circuit.

P0773 therefore does not necessarily mean that the solenoid is mechanically stuck.

P0773 vs. P0771

P0771 – Shift Solenoid "E" Performance / Stuck Off

The solenoid is not producing the expected operating response or is behaving as though it is stuck off.

P0773 – Electrical Malfunction

The primary detected problem is electrical.

P0773 vs. P0770

P0770 – Shift Solenoid "E" Malfunction

A general malfunction involving Solenoid "E".

P0773 – Shift Solenoid "E" Electrical Malfunction

A more specific electrical fault has been detected.

Where Is Shift Solenoid "E"?

The location depends on the transmission design.

It can be:

• Inside the transmission

• Installed in the valve body

• Beneath the transmission pan

• Integrated into a solenoid pack

• Integrated into a mechatronic assembly

Some transmissions allow individual solenoid replacement.

Others require servicing or replacing a complete solenoid pack or mechatronic unit.

How to Diagnose P0773

P0773 should be approached as an electrical diagnosis first.

1. Scan the TCM

Use a professional scan tool to retrieve all transmission-related codes.

Check for:

• Stored codes

• Pending codes

• Freeze-frame data

• Transmission temperature

• Commanded gear

• Solenoid commands

• Input speed

• Output speed

Other codes can provide important information.

2. Check the battery voltage

Verify that the battery and charging system are operating correctly.

Low voltage can create misleading transmission-control faults.

3. Check transmission-related fuses

Inspect the relevant fuses according to the vehicle manufacturer's wiring diagram.

Do not simply replace a repeatedly blown fuse without finding the reason it failed.

4. Inspect the transmission connector

Look for:

• Corrosion

• Bent pins

• Loose terminals

• Water intrusion

• Transmission-fluid contamination

• Damaged connector housing

5. Inspect the wiring harness

Look for:

• Broken wires

• Chafing

• Pinched wiring

• Melted insulation

• Short circuits

• Previous poor repairs

Pay particular attention to areas close to the transmission and exhaust components.

6. Test circuit continuity

Check continuity between the TCM and Shift Solenoid "E" according to the wiring diagram.

An open circuit can trigger P0773.

7. Check for short circuits

Test for:

• Short to ground

• Short to power

• Short between circuits

The correct testing procedure depends on the transmission's electrical architecture.

8. Measure solenoid resistance

Measure the resistance of Shift Solenoid "E" and compare it with the manufacturer's specification.

An open coil or significantly abnormal resistance indicates a potential solenoid fault.

Do not rely on generic resistance values because specifications vary between transmissions.

9. Check the solenoid power supply

Determine whether the solenoid is receiving the correct voltage.

Some transmission designs provide power to multiple solenoids through a shared circuit, while the TCM controls the ground side.

Other systems use different architectures.

The manufacturer's wiring diagram should be followed.

10. Check the TCM control signal

Determine whether the TCM is providing the appropriate control signal.

An oscilloscope can be useful on systems that use PWM control.

11. Inspect internal transmission wiring

If the external harness and connectors are good, inspect the internal transmission wiring where accessible.

A damaged internal harness can create P0773 even when the external wiring looks perfect.

12. Test the solenoid mechanically

If the electrical circuit is correct but the solenoid remains suspect, determine whether it can move correctly.

Electrical testing alone cannot always identify mechanical sticking.

13. Check the valve body if necessary

A valve-body fault generally causes performance problems rather than a purely electrical P0773, but it may be relevant if additional transmission codes or symptoms are present.

14. Evaluate the TCM

If the wiring, power supply, connectors and solenoid are all confirmed good, the TCM driver circuit may need to be tested.

Can a Bad Solenoid Cause P0773?

Yes.

An internal coil failure can cause:

• Open circuit

• Short circuit

• Excessive resistance

• Insufficient current flow

A faulty solenoid is therefore one of the first components to test.

Can Wiring Cause P0773?

Yes.

A broken, shorted or high-resistance wire can trigger P0773.

Can a Bad Connector Cause P0773?

Yes.

A loose or corroded connector is a common type of electrical fault that should be checked before replacing expensive components.

Can a Blown Fuse Cause P0773?

Yes, depending on the vehicle.

If Solenoid "E" shares a power supply with other transmission components, a blown fuse can interrupt its operation.

The cause of the blown fuse should always be identified.

Can Low Battery Voltage Cause P0773?

Potentially.

Low system voltage can affect solenoid operation and TCM diagnostics.

Battery and alternator operation should therefore be verified.

Can Dirty Transmission Fluid Cause P0773?

Usually not directly.

Dirty fluid is more commonly associated with solenoid sticking and hydraulic performance problems.

However, severe contamination can eventually affect solenoid operation and should not be ignored.

Can Low Transmission Fluid Cause P0773?

Usually not as a direct electrical cause.

Low fluid generally creates hydraulic and transmission-performance problems rather than an electrical circuit fault.

If P0773 is present, the electrical circuit should receive priority during diagnosis.

Can a Bad Valve Body Cause P0773?

A valve-body problem by itself is less likely to produce a purely electrical P0773.

However, if other codes or symptoms are present, the valve body may still need to be inspected.

Can P0773 Cause Harsh Shifting?

Yes.

If Solenoid "E" is required for a particular shift, an electrical failure can prevent the transmission from controlling hydraulic pressure correctly.

Can P0773 Cause Transmission Slipping?

Yes, depending on the transmission.

If the affected solenoid controls a clutch-related hydraulic circuit, its failure can contribute to slipping.

Can P0773 Cause Limp Mode?

Yes.

The TCM may enter a fail-safe strategy if it cannot reliably control Solenoid "E".

Can P0773 Cause Transmission Overheating?

Potentially.

Incorrect shifting or clutch slip can generate additional heat.

Can P0773 Damage the Transmission?

The electrical fault itself does not necessarily mean that internal damage has occurred.

However, if the fault causes repeated incorrect shifts or clutch slip, continued driving can accelerate transmission wear.

Can P0773 Be Caused by the TCM?

Yes, but a TCM failure should normally be considered only after the external circuit and solenoid have been tested.

A proper diagnostic order is:

Fuse → Power Supply → Wiring → Connector → Solenoid → Internal Harness → TCM

Common Diagnostic Mistakes With P0773

Replacing the solenoid immediately

The actual problem may be a broken wire or corroded connector.

Checking only the solenoid resistance

A normal resistance reading does not prove that the entire circuit is functioning correctly.

Ignoring the wiring diagram

Transmission solenoid circuits vary considerably between manufacturers.

Ignoring the transmission connector

A loose terminal can create exactly the type of electrical problem represented by P0773.

Replacing the TCM too early

The TCM should not be blamed until the wiring and solenoid have been properly tested.

Assuming internal transmission damage

P0773 is primarily an electrical fault and does not automatically indicate mechanical transmission failure.

Using incorrect test procedures

Applying voltage directly to a solenoid without knowing the manufacturer's testing procedure can damage the component or TCM.

What Is the Correct Repair for P0773?

The repair depends on the confirmed cause.

Possible repairs include:

• Replacing Shift Solenoid "E"

• Repairing an open circuit

• Repairing a short circuit

• Repairing damaged wiring

• Replacing damaged connector terminals

• Cleaning connector corrosion

• Repairing water intrusion

• Replacing a damaged internal transmission harness

• Replacing a blown fuse after identifying its cause

• Correcting battery or charging-system problems

• Repairing the solenoid power supply

• Repairing the TCM control circuit

• Updating TCM software where applicable

• Reprogramming the TCM

• Replacing the TCM if its driver circuit is confirmed defective

How to Test the Vehicle After Repair

After the repair, the vehicle should be tested to confirm that the electrical fault has been permanently corrected.

Verify that:

• Shift Solenoid "E" receives the correct electrical supply

• The control signal is correct

• Circuit resistance is within specification

• Wiring maintains continuity

• Connectors remain secure

• The transmission shifts correctly

• No gears are missing

• No slipping occurs

• Limp mode does not activate

• No additional transmission codes appear

• P0773 does not return

The vehicle should be tested both at normal operating temperature and under the driving conditions in which the original fault occurred.

Frequently Asked Questions About P0773

What does P0773 mean?

P0773 means the transmission control system has detected an electrical malfunction involving Shift Solenoid "E" or its control circuit.

Does P0773 mean Shift Solenoid "E" is bad?

Not necessarily. Wiring, connectors, fuses, power supply and the TCM can also cause the code.

Can a broken wire cause P0773?

Yes.

Can a corroded connector cause P0773?

Yes.

Can a blown fuse cause P0773?

Yes, depending on the vehicle's electrical design.

Can low battery voltage cause P0773?

It can contribute to transmission-control faults.

Can dirty transmission fluid cause P0773?

It is less likely to cause the electrical code directly, although severe contamination can affect solenoid operation.

Can P0773 cause harsh shifting?

Yes.

Can P0773 cause slipping?

Yes, depending on which hydraulic circuit Solenoid "E" controls.

Can P0773 cause limp mode?

Yes.

Can I drive with P0773?

If the vehicle is operating normally, a short drive to a repair facility may be possible. If there is severe slipping, violent shifting, overheating or loss of gears, continued driving should be avoided.

Does P0773 mean the transmission needs to be replaced?

No. P0773 is an electrical fault code, and the problem may be limited to the solenoid, wiring or connector.

Final Thoughts on P0773

P0773 – Shift Solenoid "E" Electrical Malfunction indicates that the transmission control system has detected an electrical problem involving Shift Solenoid "E".

The most important difference between P0773 and the other Shift Solenoid "E" codes is that P0773 specifically points toward the electrical circuit.

The most logical diagnostic sequence is:

Scan Tool → Battery/Fuses → Power Supply → Wiring → Connectors → Solenoid Resistance → Control Signal → Internal Harness → TCM

A faulty solenoid is certainly possible, but a damaged wire, loose terminal, corroded connector or power-supply problem can produce the same code.

For this reason, replacing Shift Solenoid "E" without testing the complete circuit can lead to an unnecessary repair. Once the electrical system is verified, any remaining transmission-performance problems can then be investigated through the hydraulic and mechanical systems.