P1129 Chrysler Code - Closed Loop Fueling Not Achieved Bank 2
Quick Answer
The Powertrain Control Module (PCM) detects a condition where the vehicle has remained in open loop fuel control, from a start-up condition, longer than a calibrated amount of time, when conditions would have otherwise closed loop operation. Common causes include Fuel delivery system, Engine Coolant Temperature (ECT) sensor or wiring connectors, MAP sensor or wiring connectors. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
- What it means
- P1129 Chrysler indicates Closed Loop Fueling Not Achieved Bank 2.
- Common causes
- Common causes include Fuel delivery system, Engine Coolant Temperature (ECT) sensor or wiring connectors, MAP sensor or wiring connectors.
- Severity
- High - diagnose this code as soon as possible.
- Can I drive?
- Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
Code P1129 Chrysler Description
What are the Possible Causes of the DTC P1129 Chrysler?
- Fuel delivery system
- Engine Coolant Temperature (ECT) sensor or wiring connectors
- MAP sensor or wiring connectors
- O2 sensor wiring or connectors
- Engine mechanical system
How to Fix the DTC P1129 Chrysler?
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 P1129 Chrysler 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.
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Frequently Asked Questions about P1129 Chrysler Code
1. What does the OBDII code P1129 mean on a Chrysler?
P1129 indicates that the engine control module (ECM) has detected that closed-loop fuel control was not achieved for Bank 2, meaning the system is unable to properly adjust air-fuel ratios.
2. What are the symptoms of a P1129 code on a Chrysler?
Common symptoms include poor fuel economy, rough idling, hesitation during acceleration, increased emissions, and in some cases, an illuminated check engine light.
3. What causes the P1129 code on a Chrysler vehicle?
Potential causes include a faulty oxygen sensor on Bank 2, a vacuum leak, fuel delivery issues (such as a clogged fuel injector), a damaged mass airflow (MAF) sensor, or exhaust leaks.
4. Can a dirty air filter cause the P1129 code?
Yes, a dirty or clogged air filter can restrict airflow and contribute to the P1129 code by affecting the air-fuel ratio.
5. How is the P1129 code diagnosed?
A mechanic will use an OBDII scanner to confirm the code, inspect the Bank 2 oxygen sensor, check for vacuum and exhaust leaks, test the fuel system, and examine the MAF sensor for proper operation.
6. Is it safe to drive with the P1129 code on a Chrysler?
Driving with a P1129 code is not recommended, as it can lead to poor engine performance, reduced fuel efficiency, and potential long-term damage to the catalytic converter.
7. Can a faulty oxygen sensor alone trigger the P1129 code?
Yes, a malfunctioning oxygen sensor on Bank 2 is a common cause of the P1129 code, as it affects the ECM's ability to achieve closed-loop operation.
8. How do you fix a P1129 code on a Chrysler?
Repairs may include replacing a faulty oxygen sensor on Bank 2, repairing vacuum leaks, cleaning or replacing the MAF sensor, inspecting and cleaning fuel injectors, or replacing the air filter.
9. What tools are needed to troubleshoot the P1129 code?
Diagnostic tools include an OBDII scanner, a multimeter for testing sensors, a smoke machine for detecting vacuum leaks, and possibly specialized tools for inspecting the fuel system.
10. Can a software update fix the P1129 code on a Chrysler?
In rare cases, an ECM software update from the manufacturer may address the P1129 code if it’s caused by outdated programming. However, hardware issues are more common causes.
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