Pinpoint Test P: DTC P1899:00

Four Wheel Drive (4WD) Systems - Electronic Shift

Pinpoint Tests

Pinpoint Test P: DTC P1899:00

Refer to Wiring Diagram Set 34, Four-Wheel Drive Systems for schematic and connector information. Diagrams By Number

Normal Operation

The vehicle must be engaged into either 4H or 4L (and in 2H on SVT Raptor only) mode in order to operate the rear Electronic Locking Differential (ELD). When the Mode Select Switch (MSS) is engaged to lock the rear differential, a signal is sent to the ELD field coil by the Transfer Case Control Module (TCCM) through the differential lock control circuit. This signal is a duty cycle signal which is initially high to lock the differential and decreases once the differential is locked. When the differential is starting to lock, the indicator on the MSS will start to blink. When the differential is fully locked, the indicator will illuminate steady.

- DTC P1899:00 (Axle Disconnect Indicator Circuit Low: No Sub Type Information) - When not in locking mode, the TCCM senses the indicator circuit has low voltage and is always illuminated.

This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- TCCM

PINPOINT TEST P: DTC P1899:00

NOTE: Make sure the battery is fully charged before performing this pinpoint test.

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P1 CHECK THE 4WD SWITCH STATUS (4X4_SW) PID

- Ignition ON.
- Set the MSS to 4H and pull the knob to lock the rear differential.
- Monitor the 4X4_SW PID.
- Does the 4X4_SW PID indicate 4H mode?

Yes
GO to P2.

No
INSTALL a new MSS. REFER to Mode Select Switch (MSS) Service and Repair. CLEAR the DTCs. TEST the system for normal operation. REPEAT the self-test.

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P2 CHECK THE REAR ELD INDICATOR CIRCUIT FOR A SHORT TO GROUND

- Ignition OFF.
- Disconnect: TCCM C2371A.
- Disconnect: MSS C284.
- Measure the resistance between TCCM C2371A-20, circuit CCF33 (GY/YE), harness side and ground.




- Is the resistance greater than 10,000 ohms?

Yes
GO to P3.

No
REPAIR circuit CCF33 (GY/YE). CLEAR the DTCs. TEST the system for normal operation. REPEAT the self-test.

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P3 CHECK FOR CORRECT TCCM OPERATION

- Ignition OFF.
- Disconnect all TCCM connectors.
- Check for:

- corrosion.
- pushed-out pins.
- Connect all TCCM connectors and make sure they are seated correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?

Yes
INSTALL a new TCCM. REFER to Transfer Case Control Module (TCCM) Service and Repair. TEST the system for normal operation. REPEAT the self-test.

No
The system is operating correctly at this time. Concern may have been caused by a loose or corroded connector. CLEAR the DTCs. TEST the system for normal operation. REPEAT the self-test.

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