P0408 Jeep Code - Exhaust Gas Recirculation Sensor 'B' Circuit High
Quick Answer
Early Exhaust Gas Recirculation (EGR) systems components include an EGR Valve, an Engine Control Module (ECΜ) Controlled Vacuum Switch Valve or EGR Solenoid, and an EGR Vacuum Modulator. Common causes include Faulty EGR volume control solenoid valve, Carbon built up on EGR valve, EGR volume control solenoid valve harness is open or shorted. Severity is Moderate - service should be scheduled soon. The vehicle may still be drivable for short trips if it runs normally, but avoid hard driving and repair it soon.
- What it means
- P0408 Jeep indicates Exhaust Gas Recirculation Sensor 'B' Circuit High.
- Common causes
- Common causes include Faulty EGR volume control solenoid valve, Carbon built up on EGR valve, EGR volume control solenoid valve harness is open or shorted.
- Severity
- Moderate - service should be scheduled soon.
- Can I drive?
- The vehicle may still be drivable for short trips if it runs normally, but avoid hard driving and repair it soon.
Code P0408 Jeep Description
The EGR system on recently built vehicles uses a step motor to control the flow rate of EGR from the exhaust manifold. This motor has four winding phases. It operates according to the output pulse signal of the ECΜ. Two windings are turned ON and OFF in sequence. Each time an ON pulse is issued, the valve opens or closes, changing the flow rate. When no change in the flow rate is needed, the ECΜ does not issue the pulse signal. Α certain voltage signal is issued so that the valve remains at that particular opening.
What are the Possible Causes of the DTC P0408 Jeep?
- Faulty EGR volume control solenoid valve
- Carbon built up on EGR valve
- EGR volume control solenoid valve harness is open or shorted
- EGR volume control solenoid valve circuit poor electrical connection
- Faulty EGR temperature sensor and circuit
How to Fix the DTC P0408 Jeep?
Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.
What is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the P0408 Jeep code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.
Need more information about the P0408 Jeep code?
Need more information on how to fix the P0408 Jeep code? Get Access to Factory Service Manuals
Need Help with the Code?
Get the P0408 Jeep code diagnosed by a professional: Find a repair shop in your area
Frequently Asked Questions about P0408 Jeep Code
1. What does the OBDII code P0408 mean on a Jeep?
P0408 indicates a high voltage issue in the Exhaust Gas Recirculation (EGR) Sensor 'B' circuit, often linked to the EGR system's functionality.
2. What are the common symptoms of the P0408 code on a Jeep?
Symptoms may include a check engine light, poor engine performance, rough idling, reduced fuel efficiency, or hesitation during acceleration.
3. What causes the P0408 code to appear on a Jeep?
Common causes include a faulty EGR position sensor, damaged wiring or connectors in the EGR circuit, a malfunctioning EGR valve, or issues with the vehicle’s PCM (Powertrain Control Module).
4. Can I drive my Jeep with the P0408 code?
Driving with the P0408 code is not recommended as it can lead to decreased fuel efficiency, poor engine performance, and potential long-term damage to the EGR system or engine.
5. How can I fix the P0408 code on my Jeep?
Repairs may include replacing the EGR position sensor, repairing or replacing damaged wiring or connectors, cleaning or replacing the EGR valve, or reprogramming/updating the PCM if needed.
6. How do I diagnose the P0408 code on my Jeep?
Diagnosing involves using an OBDII scanner to confirm the code, visually inspecting the EGR sensor and wiring, testing the EGR position sensor voltage, and checking for proper operation of the EGR valve.
7. What tools are needed to troubleshoot the P0408 code?
You’ll need an OBDII scanner, a multimeter for voltage checks, and basic tools to inspect and potentially remove the EGR sensor or valve.
8. Could a dirty EGR valve cause the P0408 code?
Yes, a dirty or clogged EGR valve can restrict sensor readings and trigger the P0408 code.
9. How much does it cost to repair the P0408 code on a Jeep?
Repair costs vary, but replacing the EGR sensor typically costs $100–$300, while EGR valve replacement can cost $250–$500 including labor.
10. Will clearing the P0408 code fix the problem?
Clearing the code may temporarily turn off the check engine light, but unless the underlying issue is resolved, the code will likely return.
Discuss the causes and fixes for P0408 Jeep OBDII Code
Code P0408 Jeep comments
No comments found for this page.
Fix Your Car Smarter
Try the New AutoCodes App!
Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.
