P246A: Exhaust Gas Temperature Sensor Circuit Intermittent/Erratic (Bank 2 Sensor 3)

P246A flags a third bank 2 exhaust temperature probe whose reading jumps from sample to sample faster than real gas temperature could, even though every single value stays inside the legal range. The bank 2 code itself is not described by any manufacturer in public material. GM's diesel tables run the equivalent quick-change test for other probes every 100 ms: the 2025 tables count a step above 100 °C between samples, fail after 12 of 25 samples and confirm the fault in a second trip (Type B). CARB expects such erratic-signal checks on emission inputs. Loose terminals, corroded pins and harness strands weakened by heat and vibration are the usual reasons, sometimes a cracked sensor element. A steady but wrong value is P2467, a permanent short or open P2468 or P2469.

Bank 2 is the side without cylinder 1, so it only exists on V or boxer engines.

Symptoms

• MIL on after a repeated fault
• Temperature trace jumps in live data
• Fault may come and go with bumps or engine heat

Most likely causes

• Loose or corroded terminal in the probe connector
• Harness strands broken by heat and vibration
• Cracked sensing element giving unstable contact

What to check, in order

Start with the simplest. You can tick off each step.

1. Read the soot load and differential pressure with a scanner
2. Gently move the wiring with the engine running and watch whether the reading changes.
3. Check the differential pressure sensor's hoses
4. Check the temperatures before and after the filter
5. Fix any fuel injection or EGR codes before regenerating
6. Perform a regeneration while driving or at a repair shop when the diagnosis allows it

Good to know

• Repair difficulty: medium
• It affects emissions.

What each character of P246A means

• P: Powertrain: engine and transmission
• 2: Generic code: same on every make
• 4: Emissions
• 6A: Specific fault in that system

Frequently asked questions

Can I keep driving with code P246A?

If the light is on steadily, take a highway drive or go to a repair shop soon. If the car is in limp mode or the light is flashing, do not push the engine.

What causes code P246A?

The most common causes are: loose or corroded terminal in the probe connector; harness strands broken by heat and vibration; cracked sensing element giving unstable contact.

Related codes

• P2466Exhaust Gas Temperature Sensor Circuit (Bank 2 Sensor 3)
• P2467Exhaust Gas Temperature Sensor Circuit Range/Performance (Bank 2 Sensor 3)
• P2468Exhaust Gas Temperature Sensor Circuit Low (Bank 2 Sensor 3)
• P2469Exhaust Gas Temperature Sensor Circuit High (Bank 2 Sensor 3)
• P242EExhaust Gas Temperature Sensor Circuit Intermittent/Erratic (Bank 1 Sensor 3)
• P2477Exhaust Gas Temperature Sensor Circuit Intermittent/Erratic (Bank 2 Sensor 4)

Sources

• law.cornell.edu: 13 CCR 1968.2
• gsi.ext.gm.com: 25OBDG04A

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.