DTC C0327 with or without Additional DTCs Setting - 246EAU 263EAU AWD case hi2 hi4 MIL neutral NP1 NP8 P0500 P0700 P0836 performance shift transfer TCCM unwanted

When servicing the vehicle with the VIN you entered, the following diagnosis might be helpful if the vehicle exhibits the described symptoms.

1. C0327 or
2. C0327 in TCCM along with P0836 in TCM and P0500 in PCM.

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This information supplements TSB 03-04-21-001C to include additional diagnosis.

1. Refer to published service procedures for diagnosing DTC C0327 which includes basic diagnostics i.e.:

A. Visually check the TCCM wiring harness for pinched/chaffed concerns. Additional Info: In particular check the TCCM harness chaffing at the brake cable release spring.

B. Check the pin/terminal fit at the encoder motor, TCCM and underhood relay center. Pay particular attention to Connector C1, pin A7 at the TCCM.

C. Check the TCCM, body, chassis and engine ground credibility. Remove and clean any material that may cause high resistance in the circuit i.e. paint, undercoating, etc. Ensure these grounds are secure and perform a voltage drop test and record the readings for these grounds. If the engine, chand body grounds are poor the encoder motor or the TCCM can be used as an alternative ground path.

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Additional Information: Ground Locations

1. TCCM Ground: G110. SI Document ID number 738710
2. TCCM Ground for the Mode Switch: G203. SI Document ID number 403879 NOTE: If there are no other component issues that share the same ground (example: On-Star shares G203) then it may not be necessary to check G203.
3. Description location of all grounds: SI Document ID number 886132

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Please follow this diagnosis process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed. If these steps do not resolve the condition, please contact GM TAC for further diagnostic assistance. This diagnostic approach was developed for the vehicle with the VIN you entered and should not be automatically be used for other vehicles with similar symptoms.

(03 Chevrolet Avalanche 4WD) and (03 Chevrolet K Silverado 4WD) and (03 Chevrolet Suburban 4WD) and (03 Chevrolet Tahoe 4WD) and (03 GMC K Sierra 4WD) and (03 GMC Yukon 4WD) and (03 GMC Yukon XL 4WD)

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