Powertrain, generic (extended)

P2488 Exhaust Gas Temperature Sensor Circuit Range/Performance (Bank 2 Sensor 5)

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

P2488 is the rationality check for the fifth bank 2 exhaust probe: the signal is electrically valid but does not follow the operating state. No manufacturer documents P2488; a second bank with five probes is unknown in public maker material. GM's 2025 diesel tables show for bank 1 probe 5 (P2483) how such a check can work: after a soak of more than three hours the key-on value is frozen, and too small a rise during the following drive marks the probe as stuck or outside the gas stream, Type B. CARB requires rationality monitoring of inputs used by the OBD system. A comparison with the matching probe on bank 1 and with the neighbouring probes on bank 2 quickly shows whether one sensor lags behind.

Likely causes

Aged probe responding too slowly
Probe not reaching into the gas flow
Exhaust leak cooling the measuring point

Symptoms

  • Warning lamp after two trips
  • Regeneration may be inhibited

Repair estimate

DifficultyMediumDIY possible
Parts and labour€40–400
Time0.5–2 h

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

Parts involved

egt sensor b2s5

Related codes

P2483P2485P2486P2487P2489

References: law.cornell.edu, gsi.ext.gm.com.