OBD-II Trouble Code Description for P0016 GMC

Crankshaft Position – Camshaft Position Correlation

What does this mean?

OBD2 Code P0016 GM definition:
The crankshaft position sensor (CKP) and Camshaft position sensor (CMP) work in harmony to control the spark/fuel delivery and timing. They both consist of a reluctor, or tone, ring which passes over a magnetic sensor, which generates a voltage, indicating position. The crankshaft sensor is part of the primary ignition system and functions as the “trigger”. It detects the position of the crankshaft relays that information on to the PCM or the ignition module (depending on the vehicle) to control spark timing. The Camshaft position sensor detects the position of the camshafts and relays the information to the PCM. The PCM uses the CMP signal to identify the beginning of the injector sequence. What ties these two shafts and their sensors together is the timing belt or chain. The cam and crank should be precisely timed together. If the PCM detects that the Crank and Cam signals are out of time by a specific number of degrees, this P0016 GM code will set.

Symptoms

Possible sumptoms of OBD code P0016 GM
Malfunction Indicator Lamp (MIL) illumination The engine may run but with reduced performance The engine may crank but not start The engine may exhibit a rattle near the harmonic balancer indicating the tone ring is damaged The engine may start and run, but poorly

Causes

Possible causes of OBD code P0016 GM
Timing chain stretched, or timing belt skipped a tooth due to wear Misalignment of timing belt/chain Tone ring on crankshaft slipped/broken Tone ring on camshaft slipped/broken Bad crank sensor Bad cam sensor Damaged wiring to crank/cam sensor Timing belt/chain tensioner damaged

Possible Solutions

First, visually inspect the cam and crank sensors and their harnesses for damage. If you notice broken/frayed wires, repair and recheck. If you have access to a scope, check the cam and crank patterns. If a pattern is missing, suspect a bad sensor or a slipping tone ring. Remove the cam gear and the crankshaft harmonic balancer and inspect the tone rings for proper alignment and make sure they’re not loose or damaged or that they haven’t sheared the key that aligns them. If they are properly installed, replace the sensor. If the signal appears normal, then check the timing chain/belt for proper alignment. If it’s misaligned, check for a damaged tensioner that may have allowed the chain/belt to slip a tooth or several teeth. Also check that the belt/chain isn’t stretched. Repair and recheck.

Related Codes

P0017 GM P0018 GM P0019 GM P0335 GM P0336 GM P0337 GM P0338 GM P0339 GM P0385 GM P0386 GM P0387 GM P0388 GM P0389 GM