Toyota 12-Pin GTL Oil Pump & Gearbox Connector – OEM 6188-0375 / 6181-2459 | Waterproof
Direct OEM-specification replacement for the Toyota 12-pin waterproof connector used on GTL (automatic transmission) oil pump and gearbox control harnesses. Cross-references OEM part numbers 6188-0375 (male/plug side) and 6181-2459 (wire seal / harness side). Used in automatic transmission control harnesses across Toyota and Lexus platforms. Available bare or with 15cm pre-wired leads.
The automatic transmission connector is one of the most demanding connectors in the vehicle. It is submerged in automatic transmission fluid (ATF) at temperatures up to 150°C, while simultaneously carrying solenoid control signals, speed sensor signals, and temperature sensor signals. ATF contamination of the connector causes terminal corrosion that is chemically different from standard atmospheric corrosion — ATF-corroded terminals have a characteristic brown/orange deposit that significantly increases contact resistance. A corroded transmission connector causes the TCM to lose solenoid control, triggering limp mode (typically 3rd gear only) and logging multiple transmission fault codes.
| OEM Number | Type |
|---|---|
| 6188-0375 | Male (plug side) — transmission side |
| 6181-2459 | Wire seal / harness side |
| Pin Group | Function | Failure Symptom if Corroded |
|---|---|---|
| Pins 1–3 | Shift solenoid control signals (S1, S2, S3) | Limp mode, stuck in 3rd gear, P0750–P0760 |
| Pins 4–5 | Lock-up clutch solenoid control | Torque converter not locking up, P0740 |
| Pins 6–7 | Line pressure solenoid control | Harsh shifts, P0745 |
| Pins 8–9 | Input / output speed sensor signals | P0715 / P0720 — speed sensor circuit fault |
| Pins 10–11 | ATF temperature sensor signal and reference | P0710 — ATF temperature sensor circuit fault |
| Pin 12 | Ground / TCM earth return | Multiple simultaneous transmission fault codes |
| Attribute | Detail |
|---|---|
| Pin Count | 12-Pin |
| OEM Part Numbers | 6188-0375 / 6181-2459 |
| Housing Material | High-temp nylon (PA66), ATF-resistant, waterproof sealed |
| Wire Option | Bare connector / 15cm pre-wired leads |
| Application | Automatic transmission oil pump harness, gearbox control harness |
| Compatible Brands | Toyota, Lexus |
| Code | Description |
|---|---|
| P0700 | Transmission control system — malfunction indicator |
| P0710 | ATF temperature sensor — circuit malfunction |
| P0715 | Input / turbine speed sensor — circuit malfunction |
| P0740 | Torque converter clutch solenoid — circuit malfunction |
| P0745 | Pressure control solenoid A — circuit malfunction |
| P0750 | Shift solenoid A — circuit malfunction |
Q: My Toyota is stuck in 3rd gear and has P0750 — is it the connector or the solenoid?
A: Limp mode (3rd gear only) with P0750 on Toyota is frequently caused by a corroded 12-pin transmission connector rather than a failed shift solenoid. The connector is exposed to ATF contamination, which causes terminal corrosion that mimics a failed solenoid. Inspect the connector before removing the transmission valve body to replace solenoids.
Q: Are terminals included?
A: Yes, terminals are included with all variants.
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12 Pin Connectors
