Pinpoint Test N: The Vehicle Binds In Turns/Resists Turning/Pulsates/Shudders In A Straight Line
Four Wheel Drive (4WD) Systems - 2-Speed Torque-On-Demand
Pinpoint Tests
Pinpoint Test N: The Vehicle Binds in Turns/Resists Turning/Pulsates/Shudders in a Straight Line
Normal Operation
When the vehicle is operating in 4X4 AUTO, 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 Four-Wheel Drive (4WD) system to function correctly, each tire must be in good condition 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 N: THE VEHICLE BINDS IN TURNS/RESISTS TURNING/PULSATES/SHUDDERS IN A STRAIGHT LINE
NOTE: 4X4 HIGH/4X4 LOW is not intended for driving on hard/dry surfaces.
-------------------------------------------------
N1 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 N2; in 4X4 HIGH mode or 4X4 LOW mode, binding is a normal condition.
No
GO to Pinpoint Test P. Pinpoint Test P: Four-Wheel Drive (4WD) System Functional Test
-------------------------------------------------
N2 CHECK THE INDICATORS
- Review the test drive notes.
- Did any of the Instrument Cluster (IC) 4X4 indicators or the powertrain Malfunction Indicator Lamp (MIL) illuminate?
Yes
If the 4X4 or 4X4 LOW indicators stayed illuminated, GO to N3.
If the powertrain MIL stayed illuminated, GO to N4.
No
GO to N5.
-------------------------------------------------
N3 VERIFY THE FAULT
- Review the test drive notes.
- Was 4X4 HIGH or 4X4 LOW selected when the indicators were illuminated?
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 P. Pinpoint Test P: Four-Wheel Drive (4WD) System Functional Test
-------------------------------------------------
N4 CHECK FOR DTCs
- Connect the scan tool.
- Carry out the 4X4 control module self-test.
- Are DTCs retrieved?
Yes
REFER to the 4X4 Control Module DTC Chart for diagnosis. 4X4 Control Module DTC Chart
No
GO to N5.
-------------------------------------------------
N5 VERIFY THE CONCERN
- Ignition OFF.
- 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
Vehicles with limited slip rear differential: The condition may be normal and no repair action is necessary. CHECK the rear axle to verify. REFER to Differential Assembly &/or Axle Shaft Assembly. TEST the system for normal operation.
Vehicles without limited slip rear differential: 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 N6.
-------------------------------------------------
N6 CHECK THE 4WD CLUTCH PWM STATUS (4WDCPWMST) PID
- Ignition OFF.
- Connect: Transfer Case C350.
- Ignition ON.
- Clear the 4X4 control module DTCs.
- Enter the following diagnostic mode on the scan tool: DataLogger - 4X4 Control Module.
- Monitor the 4WDCPWMST PID at closed throttle, Key ON Engine OFF (KOEO).
- Is the 4WDCPWMST PID greater than 10%?
Yes
GO to N7.
No
CHECK the transfer case. REFER to Transfer Case. TEST the system for normal operation.
-------------------------------------------------
N7 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 N8.
No
VERIFY that the 4 road wheels are the same size and have similar tread depth. CHECK the ABS for faults. REFER to Antilock Brakes / Traction Control Systems. TEST the system for normal operation.
-------------------------------------------------
N8 CHECK THE TP STATUS (TPI) PID
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: DataLogger - 4X4 Control Module.
- NOTE: The TPI PID is Accelerator Pedal Position (APP) as communicated by the PCM via High Speed Controller Area Network (HS-CAN).
- Slowly move accelerator pedal from closed throttle to Wide Open Throttle (WOT) and observe the TPI PID, KOEO.
- Does the TPI PID value vary between 0 at closed throttle and 255 at WOT?
Yes
GO to N9.
No
CHECK the APP sensor and/or PCM for faults. REFER to Computers and Control Systems Information. TEST the system for normal operation.
-------------------------------------------------
N9 CHECK THE TRANSFER CASE FRONT DRIVESHAFT OUTPUT
- With the vehicle in NEUTRAL, position it on a hoist. Refer to Vehicle Jacking and Lifting.
- 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
INSTALL a new 4X4 control module. REFER to 4X4 Control Module Service and Repair. TEST the system for normal operation.
No
CHECK the transfer case. REFER to Transfer Case. TEST the system for normal operation.
-------------------------------------------------