Experiencing a check engine light in your Dodge, Chrysler, or Jeep vehicle and pulling up the OBDII code P1004? You’re not alone. This technical service bulletin (TSB) addresses the diagnostic trouble code (DTC) P1004, indicating a “Short Runner Valve Performance” issue. This guide, based on official service information, will walk you through understanding, diagnosing, and resolving this problem efficiently.
Understanding the Dodge P1004 Code and Short Runner Valve (SRV)
The P1004 code signifies a problem with the Short Runner Valve (SRV) system in your vehicle’s intake manifold. The SRV is designed to optimize engine performance across different RPM ranges. At lower speeds, the valve closes to create longer intake runners, enhancing torque. At higher speeds, it opens to shorten the runners, maximizing horsepower. When the Powertrain Control Module (PCM) detects that the SRV is not performing as expected, it triggers the P1004 code and illuminates the Malfunction Indicator Lamp (MIL), commonly known as the check engine light.
This service bulletin is particularly relevant to owners and technicians dealing with the following models:
- 2007 Chrysler Pacifica (CS) with 4.0L engine (EGQ) – Built before December 15, 2006 (MDH 1215XX)
- 2007 Chrysler Sebring (JS) with 3.5L engine (EGF) – Built before December 13, 2006 (MDH1213XX)
- 2007 Chrysler 300/Touring (LE – International Markets) with 3.5L engine (EGG) – Built before February 10, 2007 (MDH0210XX)
- 2007 Chrysler 300/Magnum/Charger (LX) with 3.5L engine (EGG) – Built before February 5, 2007 (MDH0205XX)
It’s important to note that this TSB primarily applies to vehicles built before the specified dates. If your vehicle was manufactured after these dates, this specific bulletin might not be applicable, although the P1004 code could still indicate a related issue.
Symptoms of a P1004 Code
The most common symptom associated with the P1004 code is the illumination of the MIL (check engine light). In many cases, this might be the only noticeable symptom. Some vehicle owners might not experience any drivability issues, while others could potentially notice:
- Intermittent Check Engine Light: The light may come on and off sporadically.
- Subtle Performance Issues: In rare cases, there might be a slight decrease in engine performance, particularly during transitions between low and high RPM ranges, although this is not always perceptible.
- No Other Obvious Symptoms: Often, drivers report no other symptoms besides the illuminated MIL.
The intermittent nature of the fault can make diagnosis challenging, especially as it may be more frequent in vehicles with lower mileage.
Diagnosing the P1004 Code
To accurately diagnose the P1004 code, follow these steps, utilizing a diagnostic scan tool like the StarSCAN® (or equivalent OBDII scanner):
-
Initial Scan: Connect your scan tool to the vehicle’s OBDII port and perform a system scan. Verify that DTC P1004 is present, either as an active (MIL on) or stored (MIL off) fault.
-
Check for Other DTCs: Note if any other DTCs are present besides P1004. If there are other codes related to engine or transmission issues, address those first before proceeding with the P1004 diagnosis, as they might be related or masking the SRV issue.
-
SRV Actuator Test (Verification Procedure): This TSB outlines a specific verification procedure to test the SRV actuator using the StarSCAN® tool. These steps can be adapted for other capable scan tools that offer actuator tests and data display:
- Battery Voltage: Ensure battery voltage is stable and around 13.5 volts during testing. Use a battery charger if necessary.
- Clear Faults: Clear all existing DTCs before proceeding with the actuator tests.
- De-energized State Test: Use the scan tool to view the SRV data display in its de-energized state. The expected feedback percentage should be approximately 50% ± 5%.
- Energized State Test: Use the scan tool’s actuator test menu to energize the SRV. Then, check the data display for the SRV in its energized state. The expected feedback should be around 80% ± 5%.
- Return to De-energized State: De-energize the SRV and confirm that the feedback returns to the 50% ± 5% range.
- Evaluate Feedback:
- Pass (Step 5a): If the feedback values are within the specified ranges in steps 2, 3, and 4, the SRV actuator is likely functioning correctly electrically. No further action might be required related to the actuator itself, but the PCM flash (repair procedure below) is still recommended by the TSB.
- Fail (Step 5b): If the feedback values are outside the specified ranges, proceed to step 6.
- Dynamic Test (Step 6): Clear all faults again. Start the engine and raise the RPM to 4000 in Park. In the de-energized state, check if the SRV feedback returns to 50% ± 5%.
- Pass (Step 6a): If it returns to the correct range, the issue might be intermittent or related to the PCM software. Perform the PCM reprogramming procedure.
- Fail (Step 6b): If it still fails, proceed to step 7 to investigate wiring and mechanical issues.
- Wiring and Mechanical Checks (Step 7):
- Wiring Integrity (Step 7a): Inspect the wiring and connectors to the SRV actuator for any damage, corrosion, or loose connections. Refer to wiring diagrams in service information (DealerCONNECT>TechCONNECT in the original TSB, or equivalent online resources for your vehicle). Repair any wiring issues and re-test from step 3. If wiring is okay, proceed to step 7b.
- Mechanical Binding (Step 7b): Remove the SRV actuator. Manually rotate the SRV shaft in the intake manifold. Check for free movement within the specified ranges:
- CS (Pacifica 4.0L): 11 o’clock to 9 o’clock
- JS (Sebring 3.5L): 1 o’clock to 3 o’clock
- LX/LE (300/Charger/Magnum 3.5L): 8 o’clock to 10 o’clock
- Binding Shaft: If the shaft binds or doesn’t move freely within these ranges, the intake manifold itself might be faulty and require replacement.
- Free Shaft: If the shaft rotates freely, the SRV actuator is likely the faulty component and should be replaced.
-
Post-Repair Verification: After performing any repairs (PCM flash, actuator replacement, or manifold replacement), clear all DTCs and repeat the SRV verification procedure from step 2 to ensure the system is functioning correctly and the P1004 code is resolved.
Repair Procedures for P1004
The primary repair for the P1004 code, as outlined in this service bulletin, involves reprogramming the Powertrain Control Module (PCM) with updated software. This software update likely recalibrates the PCM’s logic for monitoring SRV performance, addressing potential false positives or improving the system’s responsiveness.
PCM Reprogramming (Flashing):
This procedure requires a dealer-level scan tool with internet connectivity, like the StarSCAN® mentioned in the original TSB. Here’s a general outline of the PCM flashing process:
- Battery Stabilization: Connect a battery charger to maintain a stable voltage (around 13.5V) throughout the reprogramming process.
- Scan Tool Connection: Connect the scan tool to the vehicle’s OBDII port and to a reliable internet connection.
- PCM Identification: Use the scan tool to navigate to the PCM module and identify the current PCM part number. Record this for reference.
- Software Update: Access the scan tool’s software update or ECU flashing function. Follow the on-screen prompts to select the correct vehicle and module. The tool should connect to the manufacturer’s server to download the latest software calibration file for your PCM.
- Flash PCM: Initiate the PCM reprogramming process. Do not interrupt the process. Ensure a stable power supply and internet connection.
- Verification: Once the flash is complete, verify that the PCM part number has been updated to the new software version.
- DTC Clearing: After flashing, clear all DTCs from all modules in the vehicle, as the PCM reprogramming process can sometimes set codes in other modules.
- Authorized Modification Label: After successfully reprogramming the PCM, it is crucial to fill out the “Authorized Modification Label” (part number 04275086AB) with the relevant information (new PCM part number, TSB number, dealer code, and date) and affix it near the Vehicle Emission Control Information (VECI) label in the engine compartment.
Fig. 1 – AUTHORIZED MODIFICATION LABEL
Note: The placeholder_image_url.png should be replaced with the actual URL of the “Authorized Modification Label” image from the original TSB or a suitable replacement if hosting the image.
Parts Replacement (If Necessary):
While PCM reprogramming is the primary solution, the TSB also lists parts for replacement if the verification procedure indicates a faulty SRV actuator or a mechanically binding intake manifold. The parts listed are:
- For CS 4.0L:
- Upper Plenum: 04593578AC
- SRV Actuator: 04593676AB
- For JS 3.5L:
- Upper Plenum: 04593649AB
- SRV Actuator: 05149095AA
- For LE/LX 3.5L:
- Upper Plenum: 04591863AJ
- SRV Actuator: 04593839AA
Important Considerations:
- Dealer Service: While some experienced DIYers might be comfortable with certain diagnostic steps, PCM reprogramming typically requires dealer-level equipment and software access. It’s generally recommended to have this service performed by a qualified dealership technician.
- TSB Applicability: Always verify that this TSB applies to your specific vehicle by checking the model year, model code, engine code, and build date (MDH) ranges mentioned in the bulletin.
- Warranty Coverage: Repairs performed under this TSB might be covered under your vehicle’s warranty. Consult with your dealership for warranty information.
Conclusion
The Dodge OBDII code P1004, related to Short Runner Valve Performance, can often be resolved by a PCM software update. By following the diagnostic steps and repair procedures outlined in this service bulletin, technicians and vehicle owners can effectively address this issue, ensuring optimal engine performance and clearing the check engine light. Remember to prioritize accurate diagnosis and utilize the correct repair procedures, and when in doubt, consult with a qualified automotive technician or dealership service center.
