P0642 Cadillac Code - 5 Volt Reference 1 Circuit Low Voltage
Quick Answer
The Engine Control Module (ECM) has four (4) internal 5 Volt reference circuits (Some models have two (2) internal 5 Volt reference circuits). Common causes include Faulty Sensor on 5 Volt circuit, Sensor on 5 Volt circuit harness is open or shorted, Sensor on 5 Volt circuit poor electrical connection. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
- What it means
- P0642 Cadillac indicates 5 Volt Reference 1 Circuit Low Voltage.
- Common causes
- Common causes include Faulty Sensor on 5 Volt circuit, Sensor on 5 Volt circuit harness is open or shorted, Sensor on 5 Volt circuit poor electrical connection.
- Severity
- High - diagnose this code as soon as possible.
- Can I drive?
- Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
Code P0642 Cadillac Description
What are the Possible Causes of the DTC P0642 Cadillac?
- Faulty Sensor on 5 Volt circuit
- Sensor on 5 Volt circuit harness is open or shorted
- Sensor on 5 Volt circuit poor electrical connection
- Faulty Engine Control Module (ECM)
How to Fix the DTC P0642 Cadillac?
Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.
Code Tech Notes
The 5 Volt reference 1 circuit provides 5 Volt to the following sensors: (Some models may have different sensors, please consult the factory service manual for the list of sensors for your model and year)
- Air conditioning (A/C) refrigerant pressure sensor
- Camshaft position sensor
- Engine oil pressure sensor
- Fuel pressure sensor
- Fuel rail pressure sensor
- Fuel tank pressure sensor
- Multifunction intake air sensor
What is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the P0642 Cadillac code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.
Need more information about the P0642 Cadillac code?
Need more information on how to fix the P0642 Cadillac code? Get Access to Factory Service Manuals
Need Help with the Code?
Get the P0642 Cadillac code diagnosed by a professional: Find a repair shop in your area
Frequently Asked Questions about P0642 Cadillac Code
1. What are the common symptoms of OBDII code P0642 in a Cadillac?
- Common symptoms include issues with engine performance, such as rough idling, misfiring, or stalling. The check engine light may also illuminate on the dashboard.
2. What does the OBDII code P0642 Cadillac indicate?
- The code P0642 indicates a low voltage condition in the 5 Volt Reference 1 circuit in the vehicle's electrical system.
3. What are the potential causes of the P0642 code in a Cadillac?
- Possible causes include a faulty 5 Volt Reference 1 circuit, a short circuit, damaged wiring, a defective Engine Control Module (ECM), or a failed sensor connected to the 5 Volt Reference circuit.
4. How can I diagnose the P0642 code in my Cadillac?
- To diagnose the issue, a mechanic would typically use a diagnostic scanner to read the code, inspect the wiring and connectors related to the 5 Volt Reference 1 circuit, and test the sensors that rely on this circuit for proper voltage.
5. Can I continue driving my Cadillac with the P0642 code present?
- It is not recommended to drive the vehicle with the P0642 code active, as it can lead to further damage to the engine or electrical system. It is best to address the issue promptly.
6. How can I repair the P0642 code in my Cadillac?
- Repairing the P0642 code usually involves identifying and fixing the root cause of the low voltage condition, which may entail replacing a faulty sensor, repairing damaged wiring, or replacing the ECM if necessary.
7. Is it possible to reset the P0642 code in a Cadillac without fixing the underlying issue?
- While clearing the code using a diagnostic scanner may temporarily turn off the check engine light, the code is likely to reappear until the underlying issue is resolved.
8. Are there any DIY tips for troubleshooting the P0642 code in a Cadillac?
- DIY troubleshooting tips include visually inspecting wiring and connectors for damage, checking sensor connections, and ensuring proper voltage levels in the 5 Volt Reference 1 circuit.
9. How much does it typically cost to repair the P0642 code in a Cadillac?
- The cost of repairing the P0642 code can vary depending on the root cause of the issue, the labor rates of the repair shop, and the cost of any replacement parts needed. It is advisable to obtain estimates from multiple mechanics.
10. Can a mechanic easily fix the P0642 code in a Cadillac?
- A qualified mechanic with experience in diagnosing and repairing electrical issues should be able to effectively address the P0642 code in a Cadillac by following proper diagnostic procedures and making the necessary repairs.
Discuss the causes and fixes for P0642 Cadillac OBDII Code
Code P0642 Cadillac comments
No comments found for this page.
Fix Your Car Smarter
Try the New AutoCodes App!
Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.
