At least the code shows which sensor/sensor circuit is the issue and why the temp is reading so high. DTC P0117 Engine Coolant Temperature (ECT) Sensor Circuit Low Voltage. The ECM detects that the ECT sensor signal is warmer than 149°C (300°F) for greater than 5 s. Diagnostic Kit---Opcom/Vauxcom 200603A,Mongoose Pro GM2 running GDS2 software. I've got a code 4 situation on my 2011 Meriva which keeps coming and going. It's not the head gasket - I've recently had an oil change done and no signs at all. There is no loss of coolant at all. The thermostat has now been changed. .

opel meriva b code 4