P1197: Key Off Voltage Low

Definition

The OBD2 code P1197 indicates that the vehicle's engine control module (ECM) has detected a low voltage condition when the ignition is turned off, which may affect the performance of certain sensors or systems

Common causes

Faulty fuel pump relay
Weak or dead battery
Poor electrical connections
Faulty fuel pump
Damaged wiring or connectors
Malfunctioning engine control module (ECM)
Issues with the ignition switch

Common misdiagnoses

Faulty fuel pressure sensor
Bad fuel pump
Electrical wiring issues
Faulty engine control module (ECM)
Vacuum leaks
Throttle position sensor issues
Mass air flow sensor problems
Ignition system faults

Troubleshooting steps

1. Check Battery Voltage
2. Ensure the vehicle's battery is fully charged and in good condition. A low battery voltage can trigger this code
3. Inspect Battery Connections
4. Check the battery terminals and cables for corrosion, looseness, or damage. Clean and tighten connections as necessary
5. Examine Fuses
6. Inspect relevant fuses related to the fuel system and electrical components. Replace any blown fuses
7. Check Fuel Pump Relay
8. Test the fuel pump relay for proper operation. A faulty relay can cause low voltage issues
9. Inspect Wiring and Connectors
10. Look for damaged, frayed, or corroded wiring and connectors in the fuel system and related electrical components. Repair or replace as needed
11. Test Fuel Pump
12. Verify that the fuel pump is functioning correctly. You can do this by listening for the pump's operation when the ignition is turned on or by using a fuel pressure gauge
13. Scan for Additional Codes
14. Use an OBD-II scanner to check for any other trouble codes that may provide more context or indicate related issues
15. Check Ground Connections
16. Ensure that all ground connections related to the fuel system and engine management are secure and free of corrosion
17. Inspect the Engine Control Module (ECM)
18. If all else checks out, there may be an issue with the ECM itself. Check for software updates or faults in the module
19. Clear the Code and Test Drive
20. After performing the necessary repairs, clear the code using an OBD-II scanner and take the vehicle for a test drive to see if the code returns. If the issue persists after following these steps, it may be advisable to consult a professional mechanic for further diagnosis and repair

Definition

Common causes

Common misdiagnoses

Troubleshooting steps

1. Check Battery Voltage

2. Ensure the vehicle's battery is fully charged and in good condition. A low battery voltage can trigger this code

3. Inspect Battery Connections

4. Check the battery terminals and cables for corrosion, looseness, or damage. Clean and tighten connections as necessary

5. Examine Fuses

6. Inspect relevant fuses related to the fuel system and electrical components. Replace any blown fuses

7. Check Fuel Pump Relay

8. Test the fuel pump relay for proper operation. A faulty relay can cause low voltage issues

9. Inspect Wiring and Connectors

10. Look for damaged, frayed, or corroded wiring and connectors in the fuel system and related electrical components. Repair or replace as needed

11. Test Fuel Pump

12. Verify that the fuel pump is functioning correctly. You can do this by listening for the pump's operation when the ignition is turned on or by using a fuel pressure gauge

13. Scan for Additional Codes

14. Use an OBD-II scanner to check for any other trouble codes that may provide more context or indicate related issues

15. Check Ground Connections

16. Ensure that all ground connections related to the fuel system and engine management are secure and free of corrosion

17. Inspect the Engine Control Module (ECM)

18. If all else checks out, there may be an issue with the ECM itself. Check for software updates or faults in the module

19. Clear the Code and Test Drive

20. After performing the necessary repairs, clear the code using an OBD-II scanner and take the vehicle for a test drive to see if the code returns. If the issue persists after following these steps, it may be advisable to consult a professional mechanic for further diagnosis and repair