P20E4 — Exhaust Gas Temperature Sensor 2/3 Correlation Bank 1

The diagnostic code reports that the readings of exhaust gas temperature sensors 2 and 3 on bank 1 do not correlate as expected. It does not identify which sensor, electrical circuit or exhaust-system condition is responsible. Sensor identification and valid reference values depend on the vehicle.

Affected system: Powertrain

Symptoms

• Warning light may illuminate
• Related system function may be impaired
• Vehicle-specific symptoms vary

Possible causes

• Exhaust or emissions plumbing leak, restriction, valve fault, sensor fault, or damaged wiring
• Related wiring, connector, power or ground fault
• Vehicle-specific mechanical or control issue

What to check

• Record stored and pending codes and freeze-frame data
• Inspect the relevant exhaust or emissions plumbing and electrical connections, then compare commanded operation with sensor feedback during the enable conditions.
• Confirm measured values against the vehicle service information
• Retest under the conditions that set the code
• Inspect the relevant exhaust or emissions plumbing and electrical connections, then compare commanded operation with sensor feedback during the enable conditions.
• Repair the verified cause and confirm the code does not return

Also written as: P20E4-00, P20E400 (some scan tools add the fault-type byte, e.g. -00).