What it means
Same as P04CE with intermittent or erratic signal. EGR mixes inert exhaust into intake to lower combustion peak temperature — too little raises NOx, too much causes misfires and rough running.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
EGR temperature sensor C reports exhaust-gas temperature to the control module so it can judge EGR operation. This code sets when the sensor’s signal becomes unstable or erratic, often as the connector or harness moves or vibrates.
Common causes
Most likely first.
- Intermittent contact at connector
- Connector with intermittent contact under vibration
- Harness routed against vibrating component
Symptoms
- Check engine light on
- Pinging or knocking under load
- Power loss and hesitation
- Possible rough idle
- Failed emissions inspection (NOx)
How to diagnose it
- Use a scan tool to record freeze-frame data and watch the EGR temperature C reading for sudden dropouts or jumps as the engine warms.
- Inspect sensor C’s connector for loose fit, corrosion, damaged pins, or signs that vibration is interrupting contact.
- Trace sensor C’s harness where it passes vibrating or hot components, checking for chafing, tension, and damaged insulation.
- With the wiring diagram, check continuity and connector contact while gently moving the harness to reproduce an intermittent fault.
- If the circuit remains stable, compare sensor C’s temperature reading and response with the manufacturer’s specification and related EGR data.
Common fixes
- Reseat and secure the EGR temperature sensor C connector.
- Repair damaged or poorly routed sensor C wiring and secure it away from vibration and heat.
- Clean or repair corroded connector terminals as appropriate.
- Replace EGR temperature sensor C if its signal remains erratic with a sound circuit.
Can I keep driving?
You can usually drive gently if the engine runs normally, but avoid heavy loads if it pings, hesitates, or loses power. A faulty EGR temperature signal can impair emissions control and may let knocking or rough running worsen.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.