What Does P2629 Mean?
The oxygen sensor's pumping current trim circuit for Bank 2 Sensor 1 (upstream sensor on opposite cylinder bank) has an open circuit or electrical fault. This affects the PCM's ability to control the wide-band oxygen sensor's pumping cell for air/fuel ratio measurement.
Common Causes
45%
Faulty oxygen sensor internal circuit or pumping cell failure
30%
Damaged or corroded wiring harness or connector to O2 sensor
15%
Poor ground connection at sensor or ECM
10%
PCM/ECM internal driver circuit failure
Diagnostic Steps
1
Step 1: Locate Bank 2 Sensor 1 (opposite side from cylinder #1) and inspect connector and wiring for damage
2
Step 2: Test ground circuits for proper continuity to chassis ground (less than 1 ohm resistance)
3
Step 3: Measure pumping current circuit voltage and resistance at sensor connector per manufacturer specs
4
Step 4: Check live data for O2 sensor readings and compare Bank 1 vs Bank 2 operation
5
Step 5: Replace O2 sensor if wiring and grounds are intact; verify PCM function if problem continues
Estimated Repair Cost
$200 - $600
Parts + labor, varies by vehicle and location
The oxygen sensor's pumping current trim circuit for Bank 2 Sensor 1 (upstream sensor on opposite cylinder bank) has an open circuit or electrical fault. This affects the PCM's ability to control the wide-band oxygen sensor's pumping cell for air/fuel ratio measurement.
The most common cause of P2629 (O2 Sensor Pumping Current Trim Circuit/Open Bank 2 Sensor 1) is: Faulty oxygen sensor internal circuit or pumping cell failure
Typical repair costs for P2629 range from $200 to $600, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Safe to drive short distances but fuel economy will suffer and emissions will increase. Extended driving may damage catalytic converter on Bank 2.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P2629 to identify the root cause.
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Quick Info
Category
Powertrain
System
Emissions Control System
Difficulty
Type
Generic (SAE)
Recommended Tools
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