Pinpoint Test C: The Vehicle Does Not Shift Between 2H (4X2) and 4H (4X4 HIGH) Correctly
Four Wheel Drive (4WD) Systems - Mechanical Shift
Pinpoint Tests
Pinpoint Test C: The Vehicle Does Not Shift Between 2H (4X2) and 4H (4X4 HIGH) Correctly
Refer to Wiring Diagram Set 34, Four-Wheel Drive Systems for schematic and connector information. Diagrams By Number
Normal Operation
The Mode Indication Switch (MIS) communicates the transfer case shift lever position to the Transfer Case Control Module (TCCM). The TCCM then controls the transfer case synchronization clutch and Integrated Wheel Ends (IWEs) as necessary. If the vehicle is not responding to the operator's intentions, systematically check the necessary inputs and outputs at the TCCM, internal components of the transfer case and shift lever, IWE components and halfshafts. Check all circuits for opens and shorts to power or ground.
- DTC P1870:00 (Mechanical Transfer Case 4X4 Switch Circuit Failure: No Sub Type Information) - Fault sets when an invalid shifter position exists for 5 seconds or more while the ignition is in the ON position and the battery voltage is between 9-16 volts. Invalid shifter position would be due to circuit faults sensed by TCCM C2371A pins 2 or 3, a faulted MIS or mechanical failure of the transfer case. The TCCM treats the position as 4L.
- DTC U300D:11 (Ignition Input On/Start: Circuit Short To Ground) - Fault sets when short to ground is sensed by TCCM C2371A pin 7.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Shift lever assembly
- Transfer case internal components
- MIS
- IWEs
- Front axle assembly
PINPOINT TEST C: THE VEHICLE DOES NOT SHIFT BETWEEN 2H (4X2) AND 4H (4X4 HIGH) CORRECTLY
WARNING: When directed to drive the vehicle as part of this test, drive the vehicle on a hard surface in an area without traffic to prevent a crash. Failure to follow these instructions may result in personal injury.
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C1 CHECK FOR DTCs
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: Self Test - TCCM.
- Are any DTCs present?
Yes
For DTC P1870:00, GO to C3.
For DTC U300D:11, GO to C2.
For all other DTCs, REFER to the Transfer Case Control Module (TCCM) DTC Chart. Four Wheel Drive (4WD) Systems
No
GO to C2.
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C2 CHECK THE IGNITION POSITION (KEY_POS_4X4) AND IGNITION STATUS (KEY_STATUS_4X4) PIDs
- Enter the following diagnostic mode on the scan tool: DataLogger - TCCM.
- Monitor the KEY_POS_4X4 and KEY_STATUS_4X4 PIDs while cycling through each position.
- Do the ignition PIDs match the ignition switch positions?
Yes
GO to C3.
No
If the KEY_STATUS_4X4 PID did not match, CHECK Battery Junction Box (BJB) fuse 54 (5A). If the fuse is OK, REPAIR circuit CBB54 (VT/OG). If the fuse is not OK, REFER to the Wiring Diagrams to identify the possible causes of the circuit short. After the fault is repaired, CLEAR the DTCs. TEST the system for normal operation. REPEAT the self-test. Diagrams By Number
If the KEY_POS_4X4 PID did not match, REFER to Steering Column Switches Testing and Inspection. to diagnose the ignition switch. After the fault is repaired, CLEAR the DTCs. TEST the system for normal operation. REPEAT the self-test.
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C3 CHECK THE MIS POSITIONS MONITORING THE TRANSFER CASE CONTACT PLATE SWITCH B (PLATE_B) AND C (PLATE_C) PIDs
- Enter the following diagnostic mode on the scan tool: DataLogger - TCCM.
- Monitor the PLATE_B and PLATE _C PIDs while shifting the transfer case between 2H (4X2), 4H (4X4 HIGH) and 4L (4X4 LOW). Refer to the following chart:
- Do the PLATE_B and PLATE_C PIDs agree with the shift lever position?
Yes
GO to C8.
No
GO to C4.
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C4 CHECK THE MIS FUNCTIONALITY
- Ignition OFF.
- Disconnect: MIS C1177.
- Measure the resistance between MIS C1177 pin 1, component side and ground; and between MIS C1177 pin 2, component side and ground. (OPEN = greater than 10,000 ohms/CLOSED = less than 5 ohms.)
- Monitor the MIS pin resistance to ground while shifting the transfer case between 2H, 4H and 4L. Refer to the following chart:
- Does the MIS function per the table?
Yes
GO to C5.
No
INSTALL a new MIS. CLEAR the DTCs. TEST the system for normal operation. REPEAT the self-test.
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C5 CHECK MIS CIRCUITS FOR A SHORT TO VOLTAGE
- Disconnect: TCCM C2371A.
- Ignition ON.
- Measure the voltage between MIS C1177-1, circuit CCF18 (BU/WH), harness side and ground; and between MIS C1177-2, circuit CCF19 (GN/BN), harness side and ground.
- Is any voltage present?
Yes
REPAIR the affected circuit(s) for a short to voltage. CLEAR the DTCs. TEST the system for normal operation. REPEAT the self-test.
No
GO to C6.
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C6 CHECK THE MIS CIRCUITS FOR A SHORT TO GROUND
- Ignition OFF.
- Measure the resistance between MIS C1177-1, circuit CCF18 (BU/WH), harness side and ground; and between MIS C1177-2, circuit CCF19 (GN/BN), harness side and ground.
- Are the resistances greater than 10,000 ohms?
Yes
GO to C7.
No
REPAIR the affected circuit(s) for a short to ground. CLEAR the DTCs. TEST the system for normal operation. REPEAT the self-test.
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C7 CHECK THE MIS CIRCUITS FOR AN OPEN
- Measure the resistance between MIS C1177 and TCCM C2371A as shown below:
- Are the resistances less than 5 ohms?
Yes
GO to C22.
No
REPAIR the affected circuit(s) for an open. CLEAR the DTCs. TEST the system for normal operation. REPEAT the self-test.
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C8 CHECK THE SHIFT TO 4H
- Shift the transfer case shift lever to 4H.
- Execute tight turns on a hard surface.
- Check for presence of driveline wind-up and tire scuff.
- Are driveline wind-up and tire scuff present?
Yes
GO to C9.
No
GO to C10.
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C9 CHECK FOR 4H WHILE IN 1st GEAR
- Drive the vehicle with the transmission in 1st gear.
- Observe the vehicle speed and engine rpm.
- Is the vehicle in 4H?
Yes
GO to C13.
No
GO to C11.
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C10 CHECK THE TRANSFER CASE 4H ENGAGEMENT
- Ignition OFF.
- With the vehicle in NEUTRAL, position it on a hoist. Refer to Jacking and Lifting Service and Repair.
- Rotate the rear driveshaft while observing the front driveshaft.
- Does the front driveshaft rotate?
Yes
GO to C12.
No
GO to C11.
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C11 CHECK THE TRANSFER CASE INTERNAL 4H ENGAGEMENT
- Ignition OFF.
- With the vehicle in NEUTRAL, position it on a hoist. Refer to Jacking and Lifting Service and Repair.
- Disconnect the transfer case shift linkage.
- Manually shift the transfer case sector shaft to the full clockwise direction, then rotate counterclockwise one position while turning the rear driveshaft.
- Rotate the rear driveshaft while observing the front driveshaft.
- Does the front driveshaft rotate and 4H shift occur?
Yes
INSTALL a new shift lever assembly. REFER to Transfer Case Transfer Case Shift Lever. CLEAR the DTCs. TEST the system for normal operation. REPEAT the self-test.
No
REPAIR the transfer case. CLEAR the DTCs. TEST the system for normal operation. REPEAT the self-test.
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C12 CHECK FOR IWE ENGAGEMENT
- NOTE: The engine must be idling during the following steps to supply the vacuum required for the IWEs to engage and disengage.
- Start the engine.
- Rotate the LH front tire one revolution forward and one revolution backward while observing the LH front halfshaft and U-joint.
- Rotate the RH front tire one revolution forward and one revolution backward while observing the RH front halfshaft and U-joint.
- Did both halfshafts rotate?
Yes
CHECK that all driveline fasteners are present and tightened to the correct specification. REFER to Driveline System - General Information Specifications for further diagnosis of the front axle.
No
GO to Pinpoint Test E. Pinpoint Test E: The Front Axle Does Not Engage/Disengage Correctly
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C13 CHECK SHIFT TO 4L
- NOTE: When shifting in or out of 4L, the transmission must be in NEUTRAL and the vehicle stopped or moving less than 5 km/h (3 mph).
- Shift the transfer case shift lever to 4L.
- Execute tight turns on a hard surface.
- Check for presence of driveline wind-up and tire scuff.
- Are driveline wind-up and tire scuff present?
Yes
GO to C14.
No
GO to C15.
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C14 CHECK FOR 4L WHILE IN 1st GEAR
- Drive the vehicle with the transmission in 1st gear.
- Observe the vehicle speed and engine rpm.
- Is the vehicle in 4L?
Yes
GO to C18.
No
GO to C16.
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C15 CHECK TRANSFER CASE 4L ENGAGEMENT
- Ignition OFF.
- With the vehicle in NEUTRAL, position it on a hoist. Refer to Jacking and Lifting Service and Repair.
- Rotate the rear driveshaft while observing the front driveshaft.
- Does the front driveshaft rotate?
Yes
GO to C17.
No
GO to C16.
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C16 CHECK THE TRANSFER CASE INTERNAL 4L ENGAGEMENT
- Disconnect the transfer case shift linkage.
- Manually shift the transfer case sector shaft to the full counterclockwise direction while turning the rear driveshaft.
- Rotate the rear driveshaft while observing the front driveshaft.
- Does the front driveshaft rotate and 4L shift occur?
Yes
INSTALL a new shift lever assembly. REFER to Transfer Case Transfer Case Shift Lever. CLEAR the DTCs. TEST the system for normal operation. REPEAT the self-test.
No
REPAIR the transfer case. CLEAR the DTCs. TEST the system for normal operation. REPEAT the self-test.
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C17 CHECK FOR IWE ENGAGEMENT
- NOTE: The engine must be idling during the following steps to supply the vacuum required for the IWEs to engage and disengage.
- Start the engine.
- Rotate the LH front tire one revolution forward and one revolution backward while observing the LH front halfshaft and U-joint.
- Rotate the RH front tire one revolution forward and one revolution backward while observing the RH front halfshaft and U-joint.
- Did both front halfshafts rotate?
Yes
CHECK that all driveline fasteners are present and tightened to the correct specification. REFER to Driveline System - General Information Specifications for further diagnosis of the front axle.
No
GO to Pinpoint Test E. Pinpoint Test E: The Front Axle Does Not Engage/Disengage Correctly
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C18 CHECK THE TRANSFER CASE SHIFT TO 2H
- Ignition OFF.
- NOTE: When shifting in or out of 4L, the transmission must be in NEUTRAL and the vehicle stopped or moving less than 5 km/h (3 mph).
- Shift the transfer case shift lever to 2H.
- With the vehicle in NEUTRAL, position it on a hoist. Refer to Jacking and Lifting Service and Repair.
- Rotate the rear driveshaft.
- Did the front driveshaft rotate?
Yes
GO to C19.
No
GO to C20.
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C19 CHECK THE TRANSFER CASE INTERNAL 2H ENGAGEMENT
- With the vehicle in NEUTRAL, position it on a hoist. Refer to Jacking and Lifting Service and Repair.
- Disconnect the transfer case shift linkage.
- Manually shift the transfer case sector shaft to the full clockwise direction while turning the rear driveshaft.
- Rotate the rear driveshaft while observing the front driveshaft.
- Did the front driveshaft remain stationary and 2H shift occur?
Yes
INSTALL a new transfer case shift lever assembly. REFER to Transfer Case Transfer Case Shift Lever. CLEAR the DTCs. TEST the system for normal operation. REPEAT the self-test.
No
REPAIR the transfer case. CLEAR the DTCs. TEST the system for normal operation. REPEAT the self-test.
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C20 CHECK FOR TRANSFER CASE 4H ENGAGEMENT
- Drive the vehicle with the transmission in 1st gear.
- Observe the vehicle speed and engine rpm.
- Is the transfer case in HIGH range?
Yes
GO to C21.
No
REPAIR the transfer case. CLEAR the DTCs. TEST the system for normal operation. REPEAT the self-test.
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C21 CHECK FOR IWE DISENGAGEMENT
- NOTE: The engine must be idling during the following steps to supply the vacuum required for the IWEs to engage and disengage.
- Start the engine.
- Rotate the LH front tire one revolution forward and one revolution backward while observing the LH front halfshaft and U-joint.
- Rotate the RH front tire one revolution forward and one revolution backward while observing the RH front halfshaft and U-joint.
- Do either of the front halfshafts rotate?
Yes
GO to Pinpoint Test E. Pinpoint Test E: The Front Axle Does Not Engage/Disengage Correctly
No
IDENTIFY the concern and GO to Symptom Chart - Four-Wheel Drive (4WD) System. Four Wheel Drive (4WD) Systems
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C22 CHECK FOR CORRECT TCCM OPERATION
- 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
GO to Pinpoint Test D. Pinpoint Test D: The Vehicle Does Not Shift Between 4H (4X4 HIGH) and 4L (4X4 LOW) Modes Correctly
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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