DTC Troubleshooting: P0126 (86)
DTC P0126:
 Insufficient Engine Coolant Temperature
NOTE: Before you troubleshoot, record all freeze data and review the general troubleshooting information.
  1. Check the ECT SENSOR 1 in the DATA LIST with the HDS.
Is about 20 °C (68 °F) or less indicated?
YES -
Go to Step 2 .
NO -
Intermittent failure, the system is OK at this time. Check the thermostat and the cooling system.■
  1. Start the engine, and let it idle for 20 minutes.
  1. Check the ECT SENSOR 1 in the DATA LIST with the HDS.
Is about 20 °C (68 °F) or less indicated?
YES -
Go to Step 4 .
NO -
Intermittent failure, the system is OK at this time. Check the thermostat and the cooling system.■
  1. Turn the ignition switch OFF.
  1. Replace ECT sensor 1.
  1. Turn the ignition switch ON (II).
  1. Reset the ECM with the HDS.
  1. Allow the engine to cool below 20 °C (68 °F).
  1. Start the engine, and let it idle for 20 minutes.
  1. Check for Temporary DTCs or DTCs with the HDS.
Is DTC P0126 indicated?
YES -
Check for poor connections or loose terminals at ECT sensor 1 and ECM, then go to Step 1 .
NO -
Go to Step 11 .
  1. Monitor the OBD STATUS for DTC P0126 in the DTCs MENU with the HDS.
Does the screen indicate PASSED?
YES -
Troubleshooting is complete. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.■
NO -
If the screen indicates FAILED, check for poor connections or loose terminals at ECT sensor 1 and the ECM, then go to Step 1 . If the screen indicates NOT COMPLETED, go to Step 8 .