P2428: Exhaust Gas Temperature Too High (Bank 1)

P2428 is a protection code: the exhaust on bank 1 has become hot enough to endanger the aftertreatment, above all the diesel particulate filter. GM's 2014 diesel tables (14OBDG04) list five triggers, any of which fails the test after 6 seconds: about 800 °C ahead of the oxidation catalyst, 900 °C behind it, 800 °C behind the filter, or rises of more than 600 °C across the catalyst and 400 °C across the filter. The fault is Type A, so the lamp comes on at once. The usual origin is an uncontrolled soot burn in the filter, late fuel injected during regeneration or a leaking injector. CARB requires plausible EGT sensors, so a faulty sensor must be ruled out first. Engine power is usually limited.

Bank 1 is the side of the engine with cylinder 1. Inline engines only have this bank.

Symptoms

• Warning lamp on immediately, often with reduced power
• Strong heat or burning smell from the exhaust
• Particulate filter or catalyst damage in severe cases

Most likely causes

• Uncontrolled soot burn in an overloaded particulate filter
• Leaking injector or excessive post-injection reaching the catalyst
• Exhaust temperature sensor reading too high

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. Check the sensor's ground and make sure the signal wire is not receiving voltage from another circuit.
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: hard
• It can trigger limp mode.
• It affects emissions.

What each character of P2428 means

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

Frequently asked questions

Can I keep driving with code P2428?

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 P2428?

The most common causes are: uncontrolled soot burn in an overloaded particulate filter; leaking injector or excessive post-injection reaching the catalyst; exhaust temperature sensor reading too high.

Related codes

• P2429Exhaust Gas Temperature Too High (Bank 2)
• P2463Diesel Particulate Filter Restriction - Soot Accumulation (Bank 1)
• P242FParticulate Filter Restriction - Ash Accumulation (Bank 1)
• P0544Exhaust Gas Temperature Sensor Circuit Bank 1 Sensor 1
• P2080Exhaust Gas Temperature Sensor Circuit Range/Performance (Bank 1 Sensor 1)

Sources

• gsi.ext.gm.com: 14OBDG04 Engine Diagnostics
• law.cornell.edu: 13 CCR 1968.2

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.