P0123: How to Diagnose & Fix — Throttle/Pedal Position Sensor/Switch 'A' Circuit High Input

The electronic throttle module (ETM) on S40/V50 models with the 2.4L non-turbo (B5244S) and early T5 engines fails due to internal solder joint cracking from thermal cycling. The ETM controls the throttle blade electronically, and when it fails, the engine enters limp mode with severely limited power or refuses to rev above idle. The issue primarily affects pre-2008 models, as Volvo updated the ETM design. Volvo issued an extended warranty program for the ETM on affected models. The ETM failure is distinct from the P2 platform (older S60/V70) ETM issue but has similar symptoms.

Many owners of 2000-2011 Rangers report intermittent high idle, unstable idle, or stalling when coming to a stop, often traced to a failing throttle position sensor, dirty or failing idle air control valve, or both. The problem is especially common on older cable-throttle trucks where carbon buildup and sensor wear accumulate with age. Symptoms can be inconsistent, which leads to repeated parts swapping before the root cause is isolated.

The throttle-body-mounted TPS wears and produces an erratic voltage signal, causing high/hunting idle, stalling at stops, hesitation or bucking on acceleration, and — on automatics — erratic or harsh shifting. A very common, high-search TJ driveability complaint that often illuminates the check-engine light.

The CD3 Edge uses a Ford electronic throttle body (ETB) with an integrated throttle position sensor. Non-conductive deposits build up on the internal sensor contacts, so the PCM sees an implausible or drifting throttle plate position and drops the vehicle into failsafe/limp mode - the amber wrench warning lights up and engine output is cut to idle-ish power, often at highway speed with no warning. Owners describe it as the truck 'just quitting on me' merging or passing, sometimes clearing after a key cycle and then recurring more frequently. Cleaning the throttle bore does not fix it because the fault is on the electronic contacts inside the sealed unit, not carbon on the plate. Ford acknowledged the family-wide ETB problem with extended coverage programs on several models, and the failure is heavily represented in NHTSA complaints for the Edge.

The 2001-2004 S60 (and other P2 platform Volvos) is notorious for ETM failure due to a design flaw in the throttle body electronics. The module develops internal solder joint cracks and corroded contacts, causing the car to enter limp mode, stall at idle, or refuse to accelerate. Volvo issued an extended warranty covering ETMs up to 10 years/200,000 miles, but many are now beyond that coverage.