P1736: Second Gear Switch Circuit Malfunction

Definition

The OBD2 code P1736 indicates a malfunction in the second gear switch circuit, which may affect the transmission's ability to properly engage or recognize second gear

Common causes

Faulty second gear switch
Wiring issues (shorts, opens, or corrosion)
Poor electrical connections
Transmission control module (TCM) malfunction
Faulty transmission solenoid
Internal transmission problems
Software issues in the TCM

Common misdiagnoses

Transmission fluid issues
Faulty transmission control module (TCM)
Wiring or connector problems
Faulty transmission range sensor
Malfunctioning shift solenoids
Internal transmission damage
Engine control module (ECM) issues
Incorrectly diagnosed sensor failures

Troubleshooting steps

1. Check for Additional Codes

Use an OBD-II scanner to check for any other trouble codes that may be present. This can help identify related issues that may be affecting the transmission
2. Inspect the Wiring and Connectors
3. Visually inspect the wiring and connectors associated with the second gear switch. Look for signs of damage, corrosion, or loose connections
4. Ensure that the wiring harness is not pinched or frayed
5. Test the Second Gear Switch
6. If accessible, test the second gear switch for proper operation. This may involve checking the switch's resistance or continuity with a multimeter
7. If the switch is faulty, it may need to be replaced
8. Check Transmission Fluid Level and Condition
9. Ensure that the transmission fluid is at the correct level and in good condition. Low or dirty fluid can cause transmission issues
10. If the fluid is dirty, consider performing a transmission fluid change
11. Inspect the Transmission Control Module (TCM)
12. Check for any issues with the TCM, as it controls the operation of the transmission. Ensure that it is functioning properly and that there are no software issues
13. If necessary, reprogram or replace the TCM
14. Look for Mechanical Issues
15. Inspect the transmission for any mechanical problems that could affect the second gear operation, such as worn components or internal damage
16. If you suspect mechanical issues, a professional transmission inspection may be necessary
17. Clear the Codes and Test Drive
18. After performing the necessary repairs or adjustments, clear the trouble codes using the OBD-II scanner
19. Take the vehicle for a test drive to see if the code reappears. Monitor the transmission's performance during the drive
20. Consult a Professional
21. If the issue persists after performing the above steps, it may be best to consult a professional mechanic or transmission specialist for further diagnosis and repair. By following these troubleshooting steps, you can identify and resolve the underlying issues causing the P1736 code

Definition

Common causes

Common misdiagnoses

Troubleshooting steps

1. Check for Additional Codes

2. Inspect the Wiring and Connectors

3. Visually inspect the wiring and connectors associated with the second gear switch. Look for signs of damage, corrosion, or loose connections

4. Ensure that the wiring harness is not pinched or frayed

5. Test the Second Gear Switch

6. If accessible, test the second gear switch for proper operation. This may involve checking the switch's resistance or continuity with a multimeter

7. If the switch is faulty, it may need to be replaced

8. Check Transmission Fluid Level and Condition

9. Ensure that the transmission fluid is at the correct level and in good condition. Low or dirty fluid can cause transmission issues

10. If the fluid is dirty, consider performing a transmission fluid change

11. Inspect the Transmission Control Module (TCM)

12. Check for any issues with the TCM, as it controls the operation of the transmission. Ensure that it is functioning properly and that there are no software issues

13. If necessary, reprogram or replace the TCM

14. Look for Mechanical Issues

15. Inspect the transmission for any mechanical problems that could affect the second gear operation, such as worn components or internal damage

16. If you suspect mechanical issues, a professional transmission inspection may be necessary

17. Clear the Codes and Test Drive

18. After performing the necessary repairs or adjustments, clear the trouble codes using the OBD-II scanner

19. Take the vehicle for a test drive to see if the code reappears. Monitor the transmission's performance during the drive

20. Consult a Professional

21. If the issue persists after performing the above steps, it may be best to consult a professional mechanic or transmission specialist for further diagnosis and repair. By following these troubleshooting steps, you can identify and resolve the underlying issues causing the P1736 code