U1060 SCP Bus Communication Failure
The U1060 code indicates that a control module (typically the PCM, GEM, or instrument cluster) has detected missing expected messages or invalid data from the Primary ID on the SCP (Standard Corporate Protocol) bus, which uses the J1850 VPW physical layer. This results in a loss of communication on the high-speed body/chassis network (41.6 kbps), preventing critical data exchange between modules such as the PCM, ABS, instrument cluster, and GEM.
1. Commonly Affected Makes
2. Most Common Causes
- Open circuit, short to ground, short to battery, or short between SCP+ and SCP- bus wires
- Failed module that transmits the Primary ID (e.g., PCM, instrument cluster, GEM)
- Damaged or missing bus termination resistors
- Excessive electromagnetic interference (EMI) in the wiring harness
- Internal failure of the receiving module (message processing error)
3. Symptoms You Will Notice
- Check Engine Light or other warning lights illuminated
- Multiple systems inoperative (e.g., gauges, ABS, power windows, door locks)
- Vehicle may not start or run poorly
- Intermittent electrical issues
4. Step-by-Step Diagnosis
Scan all modules for related communication codes and note which modules are offline
Inspect the SCP bus wiring for damage, corrosion, or shorts; check continuity and resistance between SCP+ and SCP-
Measure bus termination resistance at the OBD-II connector (should be ~60 ohms with two 120-ohm resistors)
Isolate the faulty module by disconnecting modules one at a time while monitoring bus activity
If wiring and terminations are good, suspect a failed module (PCM, cluster, or GEM) and test or replace as needed
5. Frequently Asked Questions
Is it safe to drive?▼
The severity is medium. You may be able to drive short distances, but multiple systems could fail unexpectedly, including safety systems like ABS. It is recommended to diagnose and repair promptly.
How much does it cost to fix?▼
Costs vary widely: simple wiring repairs may be $100-$200, while replacing a module like the PCM or GEM can range from $300 to $1,000+ including labor and programming.