ECT codes keep coming back

What does the computer say the coolant temp. Sensor is reading compared to actual temp?

P1115 and P1117 are for the front and rear HO2S heater circuit. Why did you replace the ECT and expect it to solve the problem?

Khlow2008 is correct P1115 is front heater low voltage and P0117 is rear heater voltage low voltage.I would suspect maybe a ground issue for the O2 sensor. It was pretty early when ianswered this question lol so I looked at the codes like librat69.I would have caught by this reply when looked up the codes you looked up codes P0115 and P0117 which are coolant temp sensor codes. Unless you posted the wrong codes in your question?

When codes occurs, it does not necessarily mean a component is faulty. It could be the wirings or a faulty PCM etc.

Were the HO2S OEM or after market?

I don't know which is correct but these are from our database.

DTC P1115: HO2S (FRONT) HEATER VOLTAGE LOW

Heated Oxygen Sensor (HO2S) (front) heater circuit voltage low code may be set by:

a) HO2S (front) malfunction.
B) Open or short circuit between HO2S (front) terminal No. 3 and PCM connector C211 terminal No. 37.
C) Open circuit between HO2S terminal No. 1 and EGI main relay terminal No. 5.

1. Check HO2S (front) and PCM connectors. Repair as needed. Go to next step.

2. Check PCM pin voltage at connector C211 terminal No. 37. If voltage is correct, go to step 6). If voltage is
out of specification, go to next step.

3. Disconnect HO2S connector. Turn ignition on. If battery voltage exists at connector terminal No. 1, go to next step. If battery voltage does not exist, repair open circuit between HO2S terminal No. 1 and EGI main relay terminal No. 5.

4. Check continuity between HO2S (front) terminal No. 3 and PCM connector C211 terminal No. 37. If continuity exists, go to next step. If continuity does not exist, repair open wiring.

5. Check circuit between HO2S (front) connector terminal No. 3 and PCM connector C211 terminal No. 37 for short to ground. Repair as needed.

6. Clear code. Recheck codes. If code returns, replace PCM. If code does not return, problem is intermittent.

DTC P1117: HO2S (REAR) HEATER VOLTAGE LOW

Heated Oxygen Sensor (HO2S) (rear) heater circuit voltage low code may be set by:

a) HO2S (rear) malfunction.
B) Open or short circuit between HO2S (rear) terminal No. 3 and PCM connector C211 terminal No. 30.
C) Open circuit between HO2S terminal No. 1 and EGI main relay terminal No. 5.

1. Check HO2S (rear) and PCM connectors. Repair as needed. Go to next step.

2. Check PCM pin voltage at connector C211 terminal No. 30. If voltage exists, go to step 6). If battery voltage does not exist, go to next step.

3. Disconnect HO2S connector. Turn ignition on. If battery voltage exists at connector terminal No. 1, go to next step. If battery voltage does not exist, repair open circuit between HO2S terminal No. 1 and EGI main relay terminal No. 5.

4. Check continuity between HO2S (rear) terminal No. 3 and PCM connector C211 terminal No. 30. If continuity exists, go to next step. If continuity does not exist, repair open wiring.

5. Check circuit between HO2S (rear) connector terminal No. 3 and PCM connector C211 terminal No. 30 for short to ground. Repair as needed.

6. Clear code. Recheck codes. If code returns, replace PCM. If code does not return, problem is intermittent.

Theres mitchell ondemand that we use to help people on here you can read what the codes are for yourself. You replaced a o2 sensor you have a code for two different o2 sensors low voltage so that means you most likely have a ground or power issue. Check the fuses first. Those are obd2 codes and the coolant temp codes for global obd2 would be P0115 and P0117 so there must have been a miss print where you got your info.

I was mistaken about the global obd2 codes being code P0115 and P0117 but a lot of car companies use P0115 and p0115 as coolant temp codes. Use your scan tool to look at the o2 sensor voltages if they constantly read low on the front and the rear one doesnt start varying voltage when gasing it then there o2 codes.