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.
2004 Lincoln Navigator RWDFACTORY OEM SERVICE PROCEDURE
Transfer Case DTCS
TRANSFER CASE (4WD CONTROL MODULE) DIAGNOSTIC TROUBLE CODE (DTC) LIST
| DTC | Description | Source | Perform Test |
|---|---|---|---|
| B1342 | ECU is Defective | 4WD control module | CLEAR the DTCs. REPEAT the 4WD control module self-test. If DTC B1342 is retrieved, INSTALL a new 4WD control module. REFER to FOUR-WHEEL DRIVE (4WD) CONTROL MODULE . CLEAR the DTCs. REPEAT the self-test. |
| B2105 | Throttle Position Input Out | 4WD | Go To PINPOINT TEST B: THE VEHICLE DOES NOT OPERATE CORRECTLY IN A4WD AND 4WD HIGH MODES . |
| B2106 | Throttle Position Input Out of Range High | 4WD control module | Go To PINPOINT TEST B: THE VEHICLE DOES NOT OPERATE CORRECTLY IN A4WD AND 4WD HIGH MODES . |
| C1728 | Transfer Case Unable to Transition Between 2H and 4H. | 4WD control module | Go To PINPOINT TEST C: NO COMMUNICATION WITH THE FOUR-WHEEL DRIVE (4WD) CONTROL MODULE . |
| C1729 | Transfer Case Unable to Transition Between 4WD HIGH and 4WD LOW | 4WD control module | Go To PINPOINT TEST D: THE VEHICLE DOES NOT SHIFT BETWEEN AUTO/4WD HIGH AND 4WD LOW MODES CORRECTLY . |
| C1979 | IWE Solenoid Circuit Failure | 4WD control module | Go To PINPOINT TEST F: DTCS C1979/C1980-IWE SOLENOID CIRCUIT FAILURE/IWE SOLENOID SHORT TO BATTERY . |
| C1980 | IWE Solenoid Short to Battery | 4WD control module | Go To PINPOINT TEST F: DTCS C1979/C1980-IWE SOLENOID CIRCUIT FAILURE/IWE SOLENOID SHORT TO BATTERY . |
| P1812 | Transmission 4-Wheel Drive Mode Select Circuit Failure | 4WD control module | Go To PINPOINT TEST D: THE VEHICLE DOES NOT SHIFT BETWEEN AUTO/4WD HIGH AND 4WD LOW MODES CORRECTLY . |
| P1815 | Transmission 4-Wheel Drive Mode Select Short Circuit to Ground | 4WD control module | Go To PINPOINT TEST A: ELECTRONIC SHIFT FUNCTIONAL TEST . |
| P1824 | Transmission 4-Wheel Drive Clutch Relay Circuit Failure | 4WD control module | Go To PINPOINT TEST A: ELECTRONIC SHIFT FUNCTIONAL TEST . |
| P1826 | Transmission 4-Wheel Drive Low Clutch Relay Short Circuit to Battery | 4WD control module | Go To PINPOINT TEST A: ELECTRONIC SHIFT FUNCTIONAL TEST . |
| P1827 | Transmission 4-Wheel Drive Low Clutch Relay Short Circuit to Ground | 4WD control module | Go To PINPOINT TEST A: ELECTRONIC SHIFT FUNCTIONAL TEST . |
| P1849 | Transmission Transfer Case Contact Plate A Short Circuit to Ground | 4WD control module | Go To PINPOINT TEST D: THE VEHICLE DOES NOT SHIFT BETWEEN AUTO/4WD HIGH AND 4WD LOW MODES CORRECTLY . |
| P1853 | Transmission Transfer Case Contact Plate B Short Circuit to Ground | 4WD control module | Go To PINPOINT TEST D: THE VEHICLE DOES NOT SHIFT BETWEEN AUTO/4WD HIGH AND 4WD LOW MODES CORRECTLY . |
| P1857 | Transmission Transfer Case Contact Plate C Short Circuit to Ground | 4WD control module | Go To PINPOINT TEST D: THE VEHICLE DOES NOT SHIFT BETWEEN AUTO/4WD HIGH AND 4WD LOW MODES CORRECTLY . |
| P1861 | Transmission Transfer Case Contact Plate D Short Circuit to Ground | 4WD control module | Go To PINPOINT TEST D: THE VEHICLE DOES NOT SHIFT BETWEEN AUTO/4WD HIGH AND 4WD LOW MODES CORRECTLY . |
| P1867 | Transmission Transfer Case Contact Plate General Circuit Failure | 4WD control module | Go To PINPOINT TEST D: THE VEHICLE DOES NOT SHIFT BETWEEN AUTO/4WD HIGH AND 4WD LOW MODES CORRECTLY . |
| P1891 | Transmission Transfer Case Contact Plate Ground Return Open Circuit | 4WD control module | Go To PINPOINT TEST D: THE VEHICLE DOES NOT SHIFT BETWEEN AUTO/4WD HIGH AND 4WD LOW MODES CORRECTLY . |
Factory Service Tools
Use the Manual With the Right Hardware
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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.
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