Pinpoint Test AL: The Vehicle Binds in Turns/Resists Turning/Pulsates/Shudders in a Straight Line
Four Wheel Drive (4WD) Systems - 1-Speed Torque-On-Demand
Pinpoint Tests
Pinpoint Test AL: The Vehicle Binds in Turns/Resists Turning/Pulsates/Shudders in a Straight Line
Normal Operation
When the vehicle is operating in All-Wheel Drive (AWD) AUTO mode, all 4 wheels receive the same amount of torque and rotate at the same speed. The amount of traction the vehicle can achieve depends on the amount of traction each tire can establish with the road surface. In order for the 4WD system to operate correctly, each wheel/tire assembly must have matching sizes and the front and rear axle ratios must match.
This pinpoint test is intended to diagnose the following:
- Unmatched tire sizes
- Unequal amounts of tire wear
- Unequal tire inflation pressures
- Unmatched front and rear axle ratios
PINPOINT TEST AL: THE VEHICLE BINDS IN TURNS/RESISTS TURNING/PULSATES/SHUDDERS IN A STRAIGHT LINE
NOTE: 4X4 is not intended for driving on hard/dry surfaces; using 4X4 mode while driving on these surfaces may produce noises like intermittent clunking, but will not damage driveline components.
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AL1 VERIFY THE CONCERN
- Test drive the vehicle on a straight stretch of road in 4X4 AUTO mode.
- Drive the vehicle through turns and parking lot maneuvers.
- Does the vehicle bind, pulsate or shudder?
Yes
If the problem occurs in 4X4 AUTO mode, GO to AL2; in 4X4 mode, binding is a normal condition.
No
GO to Pinpoint Test AH. Pinpoint Test AH: Straightline Driveline Wind-up
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AL2 CHECK THE 4X4 MODE INDICATOR
- Review the test drive notes.
- Did the 4X4 mode indicator or the powertrain malfunction indicator illuminate?
Yes
If the powertrain malfunction indicator is illuminated, GO to AL4. If the 4X4 mode indicator stays illuminated, GO to AL3.
No
GO to AL5.
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AL3 VERIFY THE FAULT
- Review the test drive notes.
- Was 4X4 mode selected when the indicators were illuminated in the Instrument Panel Cluster (IPC) message center?
Yes
The system is functioning correctly.
No
The fault may have been caused by an intermittent, uncommanded or autolock shift. TEST the system for normal operation. GO to Pinpoint Test AH. Pinpoint Test AH: Straightline Driveline Wind-up
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AL4 CHECK FOR DTCs
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: Self Test - TCCM.
- Are DTCs retrieved?
Yes
REFER to the Transfer Case Control Module (TCCM) DTC Chart for diagnosis. Four Wheel Drive (4WD) Systems - 1-Speed Torque-On-Demand
No
GO to AL5.
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AL5 VERIFY THE CONCERN
- Disconnect: Transfer Case C350.
- Test drive the vehicle on a straight stretch of road and in turns, and shift the transfer case through each mode. Record any fault conditions.
- Is the concern present?
Yes
INSPECT the driveline components for damage or wear. REFER to Inspection and Verification. TEST the system for normal operation. Inspection and Verification
No
GO to AL6.
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AL6 CHECK THE 4WD PWM CLUTCH STATUS (4WD_CLTCH_OUT) PID
- Ignition OFF.
- Connect: Transfer Case C350.
- Ignition ON.
- Clear the DTCs.
- Select 4X4 mode.
- Enter the following diagnostic mode on the scan tool: DataLogger - TCCM.
- Monitor the 4WD_CLTCH_OUT PID at closed throttle, Key ON Engine OFF (KOEO).
- Is the 4WD_CLTCH_OUT PID at least 12%?
Yes
GO to AL7.
No
CHECK the transfer case. TEST the system for normal operation.
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AL7 CHECK THE ABS MODULE WHEEL SPEED SENSOR PIDs
- Enter the following diagnostic mode on the scan tool: DataLogger - ABS Module.
- While driving the vehicle at 30 km/h (18 mph), monitor the following wheel speed sensor PIDs:
- Left Front Wheel Speed Sensor (LF_WSPD)
- Left Rear Wheel Speed Sensor (LR_WSPD)
- Right Front Wheel Speed Sensor (RF_WSPD)
- Right Rear Wheel Speed Sensor (RR_WSPD)
- Compare the speedometer reading to the wheel speed sensor PIDs.
- Do the wheel speed sensor PIDs and speedometer speeds match within 1.5 km/h (1 mph)?
Yes
GO to AL8.
No
VERIFY that the 4 road wheels are the same size and have similar tread depth. CHECK the ABS for faults. REFER to Vehicle Dynamic Systems Testing and Inspection. TEST the system for normal operation.
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AL8 CHECK THE ABSOLUTE THROTTLE POSITION (TP_TCCM) PID
- Enter the following diagnostic mode on the scan tool: DataLogger - TCCM.
- NOTE: The TP_TCCM PID is Accelerator Pedal Position (APP) as communicated by the PCM via High Speed Controller Area Network (HS-CAN).
- Slowly move throttle from closed throttle to Wide Open Throttle (WOT) and observe the TP_TCCM PID.
- Does the TP_TCCM PID value vary between 0 at closed throttle and 255 at WOT?
Yes
GO to AL9.
No
CHECK the throttle position sensor and/or PCM for faults. REFER to Computers and Control Systems. CHECK the HS-CAN, REFER to Module Communications Network Testing and Inspection. TEST the system for normal operation.
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AL9 CHECK THE TRANSFER CASE FRONT DRIVESHAFT OUTPUT
- With the vehicle in NEUTRAL, position it on a hoist. Refer to Jacking and Lifting Service and Repair.
- Rotate the front driveshaft by hand.
- Does the front driveshaft rotate freely (does it require less than 45 Nm [33 lb-ft] to rotate)?
Yes
GO to AL10.
No
CHECK the transfer case. TEST the system for normal operation.
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AL10 CHECK FOR CORRECT TCCM OPERATION
- Disconnect: TCCM C2371A and C2371B.
- Check for:
- corrosion.
- pushed-out pins.
- Connect the 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. CLEAR the DTCs. 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. REPEAT the self-test.
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