Which warning device helps you know when exhaust temperatures are abnormal?

Which warning device helps you know when exhaust temperatures are abnormal?

• A. Pyrometer warning light
• B. Coolant temperature warning light
• C. Differential warning light
• D. Both A and B

Answer: (A)

Exhaust gas temperature needs to stay within safe limits to protect the engine and the exhaust aftertreatment system. A pyrometer warning light is tied directly to measuring and signaling when those exhaust temperatures are out of range, so you can take action before damage occurs. The coolant temperature warning light monitors engine coolant, not exhaust gas, so it doesn’t indicate abnormal exhaust temperatures. The differential warning light covers drivetrain or axle conditions, not exhaust. So the pyrometer warning light is the correct indicator for abnormal exhaust temperatures.

Exhaust gas temperature needs to stay within safe limits to protect the engine and the exhaust aftertreatment system. A pyrometer warning light is tied directly to measuring and signaling when those exhaust temperatures are out of range, so you can take action before damage occurs. The coolant temperature warning light monitors engine coolant, not exhaust gas, so it doesn’t indicate abnormal exhaust temperatures. The differential warning light covers drivetrain or axle conditions, not exhaust. So the pyrometer warning light is the correct indicator for abnormal exhaust temperatures.