Exhaust Gas Temperature Sensor Circuit Low

What it means

P0545 is stored when the engine control module measures a voltage in the Exhaust Gas Temperature circuit that stays below the expected minimum. In practice this points to a short to ground, a damaged wire or a failed component rather than a mechanical problem.

This entry is compiled automatically from the standard definition and typical diagnostic practice for this type of fault. A detailed, reviewed article is in preparation.

Symptoms

• Check engine light on
• Idle too high, too low or hunting
• Stalling when coming to a stop
• Speedometer or cruise control not working in some cases

Common causes

1. Damaged, chafed or corroded wiring in the Exhaust Gas Temperature circuit
2. Corroded, loose or water-damaged connector terminals
3. Failed Exhaust Gas Temperature component (sensor, solenoid or actuator)
4. Poor ground connection for the module or component
5. Faulty control module driver (rare, confirm all else first)

How to diagnose

1. Read freeze frame data and note when the code set (cold start, under load, after rain)
2. Inspect the Exhaust Gas Temperature connector for bent pins, corrosion and water; wiggle the harness with the engine running and watch live data
3. Measure supply voltage and ground at the connector with the key on
4. Check the signal wire for shorts to ground or battery and for continuity to the control module
5. Test or substitute the Exhaust Gas Temperature only after wiring and connectors are confirmed good
6. Clear the code and complete a drive cycle to confirm the repair

Related codes

Nearby codes in this group

• P0544Exhaust Gas Temperature Sensor Circuit
• P0546Exhaust Gas Temperature Sensor Circuit High
• P0543Intake Air Heater 'A' Circuit Open
• P0547Exhaust Gas Temperature Sensor Circuit
• P0542Intake Air Heater 'A' Circuit High
• P0548Exhaust Gas Temperature Sensor Circuit Low
• P0541Intake Air Heater 'A' Circuit Low
• P0549Exhaust Gas Temperature Sensor Circuit High