Pinpoint Test T: Rear Wheels Binding When Turning Corners With the Mode Select Switch (MSS) in 2-Wheel Drive (2WD)
Electronic Locking Differential (ELD) System
Pinpoint Tests
Pinpoint Test T: Rear Wheels Binding When Turning Corners With the Mode Select Switch (MSS) in 2-Wheel Drive (2WD)
Refer to Wiring Diagram Set 34, Four-Wheel Drive Systems for schematic and connector information. Diagrams By Number
Normal Operation
When the Mode Select Switch (MSS) is engaged to lock the rear differential, a Pulse Width Modulated (PWM) signal is sent to the Electronic Locking Differential (ELD) field coil by the Transfer Case Control Module (TCCM) differential lock control circuit. This signal is a PWM signal which is initially 98% duty cycle to lock the differential and decreases to 40% duty cycle once the differential is locked. If the differential does not lock, the TCCM continues to send the signal for a set amount of time. When the differential is starting to lock, the graphic in the Instrument Panel Cluster (IPC) message center starts to blink. When the differential is fully locked, the graphic illuminates steady.
- DTC P1834:00 (Transfer Case Differential Lock-up Solenoid Short Circuit To Battery: No Sub Type Information) - The TCCM sends a signal to lock the differential. The TCCM senses that circuit CCF31 is shorted to battery voltage. The differential is constantly engaged.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- ELD field coil
- TCCM
PINPOINT TEST T: REAR WHEELS BINDING WHEN TURNING CORNERS WITH THE MODE SELECT SWITCH (MSS) IN 2-WHEEL DRIVE (2WD)
NOTE: Make sure the battery is fully charged before carrying out this pinpoint test.
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T1 CHECK FOR VOLTAGE TO THE ELD FIELD COIL
- Ignition OFF.
- Disconnect: ELD Field Coil C4359.
- Ignition ON.
- Set the Mode Select Switch (MSS) in 2H (Electronic Shift-On-The-Fly (ESOF)
- Set the Mode Select Switch (MSS) in OFF (2-Wheel Drive (2WD) or MSOS)
- Measure the voltage between ELD field coil C4359-1, circuit CCF31 (BN/VT), harness side and ground.
- Is any voltage present?
Yes
GO to T2.
No
Repair the rear differential. CLEAR the DTCs. TEST the system for normal operation. REPEAT the self-test.
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T2 CHECK THE ELD FIELD COIL CIRCUIT FOR A SHORT TO VOLTAGE
- Ignition OFF.
- Disconnect: TCCM C2371B.
- Ignition ON.
- Measure the voltage between ELD field coil C4359-1, circuit CCF31 (BN/VT), harness side and ground.
- Is any voltage present?
Yes
REPAIR circuit CCF31 (BN/VT). CLEAR the DTCs. TEST the system for normal operation. REPEAT the self-test.
No
GO to T3.
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T3 CHECK REAR LOCKING DIFFERENTIAL PWM OUTPUT CONTROL (DIFF_PWM_OS) PID
- Ignition OFF.
- Connect: ELD Field Coil C4359.
- Connect: TCCM C2371B.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: DataLogger - TCCM.
- With the MSS in 2H, monitor the DIFF_PWM_OS PID.
- Does the DIFF_PWM_OS PID read OFF?
Yes
GO to T4.
No
INSTALL a new MSS. REFER to Mode Select Switch (MSS) Mode Select Switch (MSS). CLEAR the DTCs. TEST the system for normal operation. REPEAT the self-test.
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T4 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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