What is CID 979 & How to Solve It?

What is CID 979:

cid 979 refers to a problem with the exhaust gas temperature sensor. incorrect readings can prevent proper diesel particulate filter (dpf) regeneration or trigger emission system faults.

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Why This Happens:

• faulty exhaust temperature sensor.
  
• soot accumulation blocking sensor tip.
  
• wiring harness damage due to heat.
  
• corroded connectors.
  
• ecm failure to process readings.
  
  

How to Fix It:

1. inspect exhaust system and clean soot deposits.
   
2. test sensor resistance at ambient and operating temperatures.
   
3. repair or replace burned wiring.
   
4. install a new sensor if readings remain out of range.
   
5. verify proper dpf regeneration cycle post repair.
   
   

How to Avoid It Before It Happens:

• keep exhaust system clean and serviced.
  
• avoid extended idling periods.
  
• monitor exhaust temp data during service.
  
• clue’s fleet management software helps monitor exhaust sensors and emission systems for timely maintenance.