P0773
Shift Solenoid E ElectricalP0773 is a generic OBD-II powertrain diagnostic trouble code: Shift Solenoid E Electrical. It is logged by the engine control unit when the powertrain monitor detects that a specific fault threshold has been exceeded — typically resulting in the malfunction-indicator lamp (MIL / check-engine light) being illuminated.
What P0773 means
P0773 is set when the TCM detects a confirmed electrical fault in the Shift Solenoid "E" control circuit — specifically an open circuit, short-to-ground, short-to-voltage, or coil resistance outside the manufacturer's specified range. Unlike the broader P0770 (general malfunction), P0773 pinpoints the problem to the wiring, connector, or solenoid coil rather than internal hydraulic or mechanical causes, although a mechanical failure that produces an electrical symptom (e.g., a seized solenoid drawing excess current) can also trigger it.
Common electrical failure modes include corroded connector terminals at the transmission harness plug, chafed wiring where the harness passes over the transmission case, moisture ingress into the solenoid body causing coil winding shorts, and a faulty TCM output driver. On vehicles where Solenoid E controls torque-converter lock-up, the immediate result is loss of TCC engagement and higher-than-expected cruise RPM. On vehicles where it controls a gear-range circuit, one or more ratios may become unavailable.
Because P0773 is electrically focused, diagnosis is typically more straightforward than P0770: a resistance check at the solenoid connector and a continuity test of the harness will usually isolate the fault. Connector cleaning, wiring repair, or solenoid replacement resolves most cases without requiring valve-body or internal transmission work.
Common causes
Most-frequently reported root causes when P0773 is logged.
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1
Faulty Shift Solenoid E with an open or shorted internal coil winding.
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2
Corroded, spread, or damaged connector pins at the solenoid or transmission harness plug.
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3
Chafed or broken wiring in the solenoid E control circuit.
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4
Short-to-ground or short-to-voltage caused by harness contact with the transmission case.
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5
Blown fuse or damaged relay in the solenoid power-supply circuit.
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6
Failed TCM output driver circuit unable to control the solenoid.
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7
Moisture or fluid contamination entering the solenoid body and shorting the coil.
Symptoms drivers notice
How to diagnose P0773
A typical diagnostic flow when this code is present.
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1
Retrieve all stored DTCs and freeze-frame data; note whether P0770 or TCC slip codes are also present.
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2
Inspect the transmission external wiring harness and connector for chafing, corrosion, and bent or pushed-back pins.
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3
Measure solenoid E coil resistance at the transmission connector (manufacturer spec is typically 10–30 Ω); an open or short confirms solenoid failure.
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4
Check for supply voltage and proper ground at the solenoid connector with ignition on and engine off.
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5
Test harness continuity from the solenoid connector back to the TCM connector, looking for opens or unintended continuity to chassis ground.
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6
If harness and solenoid pass electrical checks, inspect the TCM connector and verify the driver output with a lab scope.
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7
Replace the faulty component (solenoid, wiring, or TCM driver) and perform a drive cycle to confirm the code does not return.
Related powertrain codes
- P0700 — Transmission Control System Malfunction
- P0701 — Transmission Control System Range/Performance
- P0702 — Transmission Control System Electrical
- P0703 — Torque Converter/Brake Switch B Circuit Malfunction
- P0704 — Clutch Switch Input Circuit Malfunction
- P0705 — Transmission Range Sensor A Circuit malfunction (PRNDL Input)
Frequently asked questions
How do I tell P0773 apart from P0770?
P0773 is specifically an electrical fault — the TCM measured an abnormal voltage or resistance in the Solenoid E circuit. P0770 is a broader malfunction that can include mechanical or hydraulic causes. If you have only P0773, start with wiring and solenoid resistance checks.
Can a bad ground cause P0773?
Yes. A high-resistance or open transmission-harness ground creates a voltage offset at the solenoid that the TCM interprets as an electrical fault, even if the solenoid itself is healthy.
Will P0773 clear itself after a repair?
Once the electrical fault is corrected, the code will self-clear after a successful drive cycle in most TCMs. Use a scan tool to clear it manually so the readiness monitors reset promptly.
Is solenoid E always the TCC solenoid?
On many Toyota and Honda platforms, yes. On other transmission designs Solenoid E may control a different gear-range clutch. Always confirm the function using a vehicle-specific wiring diagram before condemning the torque converter.
Disabling P0773 in software
RaceTune can permanently disable P0773 — and any other OBD-II diagnostic trouble code — on every ECU family we support. The monitor is disabled inside the ECU itself, so the fault stops being logged: the warning light stays off and the engine never enters limp mode for this code. The change is tied to your exact software version.
Software modifications affect emissions compliance and are not road-legal in many jurisdictions. RaceTune service files are intended for motorsport, off-road, and export use.
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