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2007 Chevrolet Impala P0121 and P2135 Fault Code Diagnosis - Pedal Position Sensor Issue?

Model: 07 chevy Impala Fault Code: P0121 Posted: 2017-02-08 17:30

My 2007 Chevrolet Impala has been running reliably, but recently it triggered both fault codes P0121 and P2135. I believe these codes are pointing to a potential failure in the pedal position sensor. Specifically, P2135 indicates a mismatch between the throttle position sensor (TPS) and pedal position sensor readings. Since both sensors rely on accurate input signals for engine control, a discrepancy could stem from a faulty pedal position sensor or an electrical issue in the sensor circuit. I'm seeking advice from experienced users—any insights into diagnosing this issue would be greatly appreciated. Is there a known technical service bulletin (TSB) that addresses this problem? I've found references to TSB 12-06-04-003A, but I'd like confirmation on its relevance and applicability to my vehicle model and year.

Related fault codes
P0121P2135
Comments (5)
Anonymous 2017-02-09 12:47

Consider reviewing TSB 12-06-04-003A—it may provide a specific repair procedure for the pedal position sensor issue in your 2007 Chevrolet Impala. This bulletin is available free of charge and can be accessed at http://revbase.com/BBBMotor/.

Anonymous 2017-02-09 21:55

I've encountered both P0121 and P2135 codes on my wife's 2007 Impala recently. I don't have access to the Mitchell On-Board Diagnostic system—does anyone know of a free, accessible tool or resource that can help interpret these fault codes?

Anonymous 2017-02-09 23:02

All official TSBs are publicly available for free at http://revbase.com/BBBMotor/. This site hosts detailed technical bulletins for various vehicle models, including the 2007 Chevrolet Impala.

Anonymous 2017-02-10 05:40

Thanks for sharing the link. I found TSB 12-06-04-003A there, but one of the download links was broken and failed to load. I tried two different versions, only one worked—this makes accessing critical repair info quite frustrating.

Anonymous 2017-02-10 09:08

The issue may stem from a mismatch between throttle position sensor (TPS) 1 and TPS 2 readings relative to the pedal position sensor. To diagnose: 1. With ignition ON, check the TP Sensor 1 voltage reading on your scan tool—should be between 0.33V and 4.75V, varying with pedal input. 2. Check TP Sensor 2 voltage—should range from 0.25V to 4.59V, also responding to pedal movement. 3. Confirm that both sensors show agreement in the scan tool. If they don’t match, this indicates a sensor fault or wiring issue. Sorry, I have to leave now.