Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
2021 Ford Explorer STFACTORY OEM SERVICE PROCEDURE
Pinpoint Tests RI: REDUCTANT Temperature Sensor: Introduction
WARNING: This page does not describe the selected car, but rather 9 other vehicles, including the 2018 Ford Transit-350 HD, 2018 Ford Transit-350, 2018 Ford Transit-250, 2018 Ford Transit-150, and 2018 Ford F-550 Super Duty. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
Regeneration may occur during normal operation. During regeneration, diagnostic procedures may display biased values. If a regeneration occurs during diagnostic procedures, allow the process to complete before continuing diagnostics.
This pinpoint test is intended to diagnose the following:
- reductant temperature sensor
- reductant pump assembly
- harness circuits: RDT and SIGRTN
- reductant dosage control module (5H298)
- PCM (12A650)
REDUCTANT TEMPERATURE SENSOR EXPECTED VALUES
| Temperature (°C) | Temperature (° F) | Resistance (K Ohms, Transit) | Resistance (K Ohms, All Others) |
|---|---|---|---|
| -40 | -40 | 336 | 45 |
| -30 | -22 | 177 | 26 |
| -20 | -4 | 97 | 16 |
| -10 | 14 | 55 | 9.4 |
| 0 | 32 | 32 | 5.9 |
| 10 | 50 | 20 | 3.8 |
| 20 | 68 | 12 | 2.5 |
| 30 | 86 | 8 | 1.7 |
| 40 | 104 | 5.3 | 1.2 |
| 50 | 122 | 3.6 | 0.84 |
| 60 | 140 | 2.5 | 0.60 |
| 70 | 158 | 1.8 | 0.44 |
| 80 | 176 | 1.2 | 0.32 |
| Pin | Circuit |
|---|---|
| 5 | SIGRTN (Signal Return) |
| 3 | RDT (Reductant Temperature) |
| Pin | Circuit |
|---|---|
| 2 | SIGRTN (Signal Return) |
| 1 | RDT (Reductant Temperature) |
| Pin | Circuit |
|---|---|
| 90 | SIGRTN (Signal Return) |
| 56 | RDT (Reductant Temperature) |
| Pin | Circuit |
|---|---|
| 43 | SIGRTN (Signal Return) |
| 38 | RDT (Reductant Temperature) |
Factory Service Tools
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.