E074

Code E074 MAT Signal Interrupt






Test Condition

Engine Running

Failure Condition

Manifold air temperature change of 7 degrees or more in 250 milliseconds.

Action

Code Set, No service telltale.

Description

This diagnostic test monitors manifold air temperature for a rapid change of 7 degrees or more in temperature in a short period of time.

Test

- This code sets when the MAT temperature changes 7 degrees in .25 seconds.
- This code will not turn on the service engine soon indicator.
- This code can be caused by an open, short to ground, or short to voltage in CKT 472 and/or 469; an open or short in the sensor connector, engine to dash connector, or ECM connector. A defective sensor can also cause the code.
- This code will never set current, since it is set by a MAT sensor value which changes faster than what can occur in a normally operating system.
- This code indicates an intermittent signal fault which could cause a driveability symptom.
- To diagnose, see notes on intermittents.

- When all diagnosis and repairs are completed, clear codes and verify proper operation.