P0197
DTC P0197: EOT Sensor Circuit Low Voltage1. Reset the ECM with the HDS.
2. Start the engine. Hold the engine speed at 3,000 rpm without load (in Park or neutral) until the radiator fan comes on, then let it idle.
3. Check for Temporary DTCs or DTCs with the HDS.
Is DTC P0197 indicated?
YES - Go to step 4.
NO - Intermittent failure, system is OK at this time. Check for poor connections or loose terminals at the EOT sensor and the ECM.
4. Turn the ignition switch OFF.
5. Disconnect the EOT sensor 2P connector.
6. Measure resistance between EOT sensor 2P connector terminals No.1 and No.2.
Is there proper resistance (see table)?
YES - Go to step 7.
NO - Replace the EOT sensor.
7. Wait for 1 minute. If the radiator fan is running, wait for 1 minute after it stops.
8. Disconnect ECM connector C (22P).
9. Check for continuity between EOT sensor 2P connector terminal No.2 and body ground.
Is there continuity?
YES - Repair short in the wire between the ECM (C1) and the EOT sensor
NO - Update the ECM if it does not have the latest software, or substitute a known-good ECM, then recheck. If the symptom/indication goes away with a known-good ECM, replace the original ECM.