Powertrain, generic (extended)

P2484 Exhaust Gas Temperature Sensor Circuit Intermittent/Erratic (Bank 1 Sensor 5)

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

P2484 catches a fifth bank 1 exhaust probe whose signal jumps faster than any real exhaust temperature can change. GM's diesel ECMs compare consecutive samples taken every 100 ms. In the 2018 table the resistance difference between two samples is evaluated, and 15 failed samples out of 30 set a Type B code. The 2025 table uses a temperature step above 100 °C, needs 12 of 25 samples and runs only while the unfiltered value lies between 140 and 1070 °C and no electrical fault of the probe is present. GM lists internal probe faults, worn harnesses and connector problems as failure modes. Unlike P2481 and P2482, the signal stays within its limits, so wiggle tests on the harness while watching live data are the quickest way in.

Likely causes

Intermittent contact in the probe connector
Harness insulation worn by heat or rubbing
Probe element cracking internally

Symptoms

  • Warning lamp, sometimes going out again
  • Erratic jumps of probe 5 in live data

Repair estimate

DifficultyMediumDIY possible
Parts and labour€40–350
Time0.5–2.5 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

egt sensor b1s5

Related codes

P2480P2481P2482P2483P2489

References: gsi.ext.gm.com, gsi.ext.gm.com, gsi.ext.gm.com.