U1063 SCP Bus Communication Failure
The U1063 code indicates a communication fault on the SCP (Standard Corporate Protocol) network, which is based on the SAE J1850 VPW standard. The module that logged the code has detected that the data expected from a specific module (identified by its Primary ID) is invalid, corrupted, or was not received within the programmed time window. This disrupts data exchange between modules such as the PCM, TCM, ABS, instrument cluster, or GEM.
1. Commonly Affected Makes
2. Most Common Causes
- Failed, disconnected, or unpowered transmitting module (identified by the Primary ID)
- Short to ground, battery, or between SCP bus lines (SCP+ / SCP-)
- Damaged, loose, or missing bus termination resistors
- Open or high-resistance wiring in the SCP bus
- Software configuration error or incompatible programming strategy between modules
- Internal communication circuit failure in the receiving module
3. Symptoms You Will Notice
- Check Engine Light or other warning lights illuminated
- Erratic or inoperative gauges, warning indicators, or module functions
- Possible drivability issues such as harsh shifting, no start, or reduced power
4. Step-by-Step Diagnosis
Scan all modules for codes and note which modules are not communicating
Check for technical service bulletins (TSBs) related to U1063 for the specific vehicle
Inspect the SCP bus wiring for shorts, opens, or damage, especially near connectors and module locations
Measure bus resistance at the data link connector (DLC) between SCP+ and SCP-; should be approximately 60 ohms with two termination resistors
Verify power and ground at the module identified by the Primary ID
If wiring and power are good, suspect a faulty module; perform a network test or swap modules if possible
5. Frequently Asked Questions
Is it safe to drive?▼
The severity is medium. You may be able to drive short distances, but expect warning lights and possible drivability issues. Have it diagnosed promptly to avoid further problems.
How much does it cost to fix?▼
Costs vary widely: from $50–$150 for a simple wiring repair to $200–$800+ for module replacement, depending on the module and labor rates.