P0118 Chevrolet Silverado 1500

The ECT sensor temperature is less than -39°C (-38°F) for more than 10 seconds. This is equal to more than 4.8 volts on the ECT signal circuit, as measured by the ECM.

Action Taken When the DTC Sets

1. The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

Conditions for Clearing the DTC

1. The control module turns OFF the MIL after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

Diagnostic Aids

1. If a short to a separate 5-volt source occurs, this DTC will set.
2. A skewed sensor could result in poor driveability conditions. Refer to «Temperature vs Resistance (ECT Sensor)»(ref-238192-S12637982862006072400000) or «Temperature vs Resistance (IAT Sensor)»(ref-238192-S38080664392006072400000) or «Temperature vs Resistance (IAT 2 Sensor)»(ref-238192-S39052269492006072400000) or «Temperature vs Resistance (Fuel Temperature)»(ref-238192-S26225245382006072400000) .
3. After starting the engine, the ECT should rise steadily, then stabilize when the thermostat opens.
4. If the condition is suspected of being intermittent, refer to «Testing for Intermittent Conditions and Poor Connections»(ref-238178-S33329058682006072400000) and «Inducing Intermittent Fault Conditions»(ref-238178-S02998527202006072400000) .

Schematic Reference

Engine Controls Schematics

Connector End View Reference

1. «Engine Controls Connector End Views»(ref-238192-S16921739062006072400000)
2. «Engine Control Module (ECM) Connector End Views»(ref-238192-S02812492482006072400000)

Electrical Information Reference

1. «Circuit Testing»(ref-238178-S39570233092006072400000)
2. «Connector Repairs»(ref-238178-S40461273312006072400000)
3. «Testing for Intermittent Conditions and Poor Connections»(ref-238178-S33329058682006072400000)
4. «Wiring Repairs»(ref-238178-S26381606952006072400000)

Scan Tool Reference

1. «Scan Tool Data List (Engine Control Module)»(ref-238297-S10359974192006072400000) or «Scan Tool Data List (Glow Plug Control Module)»(ref-238297-S11797710032006072400000)
2. «Scan Tool Output Controls»(ref-238297-S23484851252006072400000)