What does it mean?
Camshaft position sensor "B" on bank 2 reads a toothed target on the second camshaft of the cylinder head that does not contain cylinder number one, and on a twin cam head that is normally the exhaust camshaft. The module supplies the sensor with power and a low reference and receives a square wave whose edges tell it exactly where the camshaft is relative to the crankshaft signal, information needed for sequential injection, ignition sequencing and variable valve timing control.
This code is stored when the voltage on that signal line stays above the calibrated upper limit for longer than the monitor allows while the crankshaft signal shows the engine turning. A line locked high produces no usable edges, so the module loses camshaft angle for that bank and falls back to a default strategy. Depending on the application the engine may still run on a substitute value, but valve timing control on bank 2 is switched off.
Symptoms
- MIL (check engine lamp) on, frequently with camshaft to crankshaft correlation or variable valve timing codes on bank 2
- Longer cranking before the engine starts, since the module must work out the firing sequence without that reference
- Rough or uneven running, most noticeable at idle and light load
- Reduced power, dull throttle response and, on many vehicles, limp mode
- Poorer fuel economy because valve timing on bank 2 is held at its default position
- Occasional stalling or a random cut out while the engine is warming up
Likely causes
- Open or high resistance low reference circuit, which lets the signal line float up to reference voltage
- Signal wire shorted to battery voltage or to the sensor supply inside a damaged harness section
- Broken signal conductor leaving the module input pulled up with no pulses arriving
- Failed hall element inside the camshaft position sensor for bank 2
- Oil filling the sensor connector after a leaking sensor seal or a cam cover gasket failure
- Excessive air gap, a loose sensor bolt or a damaged target ring on the exhaust camshaft
- Corroded or spread terminals at the sensor or module connector
How to fix it
- Read the freeze frame, then check live data for camshaft signal status on both banks so the failed input can be identified with certainty
- Inspect the sensor connector for oil contamination, corrosion, spread terminals and a damaged seal, and check the harness for chafing along the cam cover
- With the ignition on and the sensor connected, backprobe the signal line and confirm it toggles while the engine is cranked; a constant high value proves the fault is present
- Unplug the sensor and measure supply voltage and the low reference at the harness side; a missing or high resistance ground explains a signal stuck high
- Check the signal wire for continuity to the module and for an unintended connection to supply voltage
- Remove the sensor and inspect its tip and the camshaft target for damage, metal debris and correct seating, and verify the mounting bolt is tight
- Replace the sensor or repair the harness according to the measurements, clear the codes and verify camshaft signal quality on both banks through cranking, idle and a road test