1. Specific Meaning for Cadillac P1392
The P1392 code on Cadillac vehicles indicates:
“Intermittent Mismatch Between Crankshaft Position Sensor (CKP) and Camshaft Position Sensor (CMP)”
This fault is particularly critical on Cadillac engines because it can affect:
- The Active Fuel Management system (AFM/DoD)
- Variable Valve Timing (VVT)
- Overall engine performance
2. Most Affected Cadillac Models
- CTS (2003-2019) – Especially 3.6L V6 (LLT/LFX)
- SRX (2004-2016) – Recurring problems on 2.8T/3.6L
- Escalade (2007-2020) – Frequent on 6.2L V8
- ATS (2013-2019) – Mainly 2.0T LTG
3. Prioritized Causes (Based on GM Technical Data)
- CMP Sensor Failure (60% of cases)
- Particularly on 3.6L V6 (premature wear)
- Timing Chain Problem (25%)
- Early stretching on LFX/LTG
- Electrical Issues (10%)
- Corroded C100/C105 connectors
- Control Module Failure (5%)
4. Advanced Diagnostic Procedure
Step 1 – Preliminary Check
- Check oil pressure (minimum 25 psi at idle)
- Inspect ECU X3 connector (known for corrosion issues)
Step 2 – Sensor Testing
| Parameter | Normal Value | Test Method |
|---|---|---|
| CMP Resistance | 850-1350Ω | Digital multimeter |
| CKP Signal | 0.5-3.0V AC | Oscilloscope |
| Phase Delay | 0-5° | GM MDI scan tool |
Step 3 – Mechanical Verification
- Use special tool J-45027 to measure chain stretch
- Check variable cam tensioner (specific GM procedure)
- Verify alignment marks (method varies by engine)
5. Technical Solutions by Engine
For 3.6L V6 (LLT/LFX)
- Replace complete timing chain kit (including revised tensioners)
- ECM software update (TSB 16-NA-383)
For 2.0T LTG
- Lubrication system overhaul
- Replacement with upgraded CMP sensor (P/N 12677925)
For 6.2L V8
- AFM system inspection
- Lifter verification
6. Critical Technical Data
- Timing Tolerance: ±3° max
- Minimum Oil Pressure: 25 psi (hot idle)
- Chain Replacement Interval: 150,000 km (but often needed at 100,000 km)
7. Average Repair Costs
| Service | Cost (USD) | Warranty |
|---|---|---|
| CMP sensor replacement | $200-400 | 2 years |
| Complete chain kit | $1,800-3,500 | 1 year |
| Software update | $150-300 | 90 days |
8. Common Workshop Mistakes
- Neglecting mandatory software updates
- Using non-OEM chain kits (causes recurrence)
- Forgetting to reset adaptives after repair
9. Technical FAQ
Q: Why is this code more serious on Cadillac?
→ Due to advanced systems (VVT, AFM) being more sensitive to timing errors.
Q: Can the repair be postponed?
→ Absolutely not – risk of catastrophic engine damage.
Q: How to prevent recurrence?
→ Use only GM Genuine parts and follow oil change intervals.
10. Technical Conclusion
The P1392 code on Cadillac requires:
- Systematic diagnosis with GM MDI tool
- Complete timing system verification
- Update of relevant software
⚠️ Official GM Recommendation: Do not exceed 500 miles (800 km) after code appearance before repair.