Exhaust Gas Recirculation Flow Insufficient
Table of contents
- Possible Causes
- How To Fix
- Tech Notes
- Cost To Diagnose
- When is the code detected
- Possible Symptoms
- Description
P0401 PONTIAC Possible Causes
- EGR passage clogged
- Faulty EGR Valve
- EGR solenoid valve harness is open or shorted
- EGR solenoid valve circuit poor electrical connection
How do I fix code P0401 PONTIAC?
Check the “Possible Causes” listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector’s pins.
Tech Notes
- EGR flow malfunction could be caused by a clogged EGR valve or EGR tube. Before replacing any parts try cleaning the EGR valve, tube and passages.
Cost of diagnosing the P0401 PONTIAC code
The cost of diagnosing the P0401 PONTIAC code is 1.0 hour of labor. The auto repair labor rates vary by location, your vehicle’s make and model, and even your engine type. Most auto repairs shops charge between $75 and $150 per hour.
When is the code detected
The Powertrain Control Module (PCM) sets a DTC P0401 when the fail counter exceeds the fail threshold. The number of test samples required to exceed the fail threshold varies according to the magnitude of the detected flow errors.
Possible Symptoms
- Engine Light ON (or Service Engine Soon Warning Light)
- Possible engine hesitation
P0401 PONTIAC Description
The Powertrain Control Module (PCM) tests the EGR system during deceleration by momentarily commanding the EGR valve open. The pressure in the intake manifold increases when the EGR valve is open. The PCM monitors the Manifold Absolute Pressure (MAP) sensor signal during the EGR system diagnostic in order to determine the amount of EGR flow. The PCM calculates an error based on the difference between the actual MAP increase and a predetermined value. The PCM records the error and adjusts an internal fail counter towards the fail threshold if the error is too great.