Parts for your 2008 Honda Civic-Camshaft sensor

2008 Honda Civic Camshaft Sensor — What It Does and How to Look After It

Based on technical references including the Honda Civic (2006–2011) Factory Service Manual published by Helm Inc., the Honda Electronic Parts Catalogue, and mainstream workshop databases (ALLDATA/Mitchell 1), the 2008 Honda Civic is fitted with a camshaft position sensor (often listed as CMP). All major engine variants use it: the 1.8L R-series (most NZ/AU models), the 2.0L K-series (Si/Type S), and the Hybrid. Some K-series models use two sensors (intake and exhaust), while the 1.8L typically uses a single sensor on the head.

The camshaft sensor’s whole job is to tell the ECU exactly where the camshaft is in its rotation. Paired with the crank sensor, it lets the ECU fire injectors sequentially, time the spark properly, and command i-VTEC/VTC cam phasing. When it’s healthy, cold starts are crisp, idle is smooth, and fuel economy stays on point. When it isn’t, the Civic can be hard to start, feel flat, or throw a check-engine light with codes like P0340 or P0341.

There’s no set service interval for the sensor, but good oil and regular servicing help keep it happy. Oil contamination, a tired O-ring, or a brittle connector are the usual culprits. On the 1.8L, the CMP typically sits on the cylinder head near the timing chain end, on the 2.0L, there may be two sensors at the front of the head, Hybrid location varies slightly but is still up top.

If replacement is on the cards, it’s a straightforward DIY for most owners under the bonnet: disconnect the battery negative, remove the engine cover, unplug the connector, and undo the small retaining bolt. Always fit a new O-ring lightly oiled, seat the sensor squarely, and tighten to the factory spec found in the service manual. Clear codes and verify live cam/crank sync if you’ve got a scan tool. Use quality OEM or reputable aftermarket parts—cheap copies can cause intermittent faults that are a pain to trace.

• Common signs: hard starting, rough idle, misfires, poor fuel use, and a check-engine light (often P0340/P0341).
• Before replacing: inspect the connector pins, wiring near the rocker cover, and look for oil leaks wicking into the plug.
• After fitting: confirm no oil seepage around the new O-ring and check for smooth idle and clean restarts.

FAQs

Where is the camshaft sensor on a 2008 Civic?
On the 1.8L R-series, it’s typically mounted on the cylinder head at the timing chain end. On 2.0L K-series Si models, there can be two—one for the intake cam and one for the exhaust—both at the front of the head. Hybrid placement is also on the head, with access from above after removing the engine cover.

Can they keep driving with a bad camshaft sensor?
The car may still run, but starting can be hit-and-miss, power may drop, and it can stall unexpectedly. It’s not ideal for safety or the health of the catalytic converter, so it’s best to diagnose and sort it promptly.

Should the crank sensor be changed at the same time?
Not necessarily. They perform different roles. Test both, inspect the wiring and connectors, and replace only what’s faulty. If the car has high kilometres and both sensors are original, some owners choose to pre-emptively replace the pair, but it’s not mandatory.