P1345 BUICK Crankshaft Position-Camshaft Position Correlation

Possible causes

– Engine mechanical condition-Valve timing off
– Cam sensor or crank sensor are loose on their mounting
– Faulty camshaft position sensor
– Faulty crankshaft position sensor

Tech description

If this DTC started after recent internal engine repairs, inspect for proper engine mechanical timing. With the camshaft cover removed and the #1 cylinder at top dead center, make sure that the darkened chain links are lined up with the alignment marks on the exhaust and intake cam sprockets.

If a P0016 or P1345 is resetting without any engine performance concerns but the above information did not isolate a cause for the DTC, replace the Cam Phaser Actuator sprocket.

When is the obd code mean?

The ECM detected that the cam and crank sensor positions were out of time

Symptoms

– Engine Light ON (or Service Engine Soon Warning Light)
– Engine hard to start
– Engine stall while driving

P1345 BUICK OBD Code Description

The Crankshaft Position (CKP) sensor is a permanent magnet generator, known as a variable reluctance sensor. The magnetic field of the sensor is altered by a crankshaft mounted reluctor wheel that has seven machined slots, 6 of which are equally spaced 60 degrees apart. The seventh slot is spaced 10 degrees after one of the 60 degree slots. The CKP sensor produces seven pulses for each revolution of the crankshaft. The pulse from the 10 degree slot is known as the sync pulse. The sync pulse is used to synchronize the coil firing sequence with the crankshaft position. The CKP sensor is connected to the powertrain control module (PCM) by a signal circuit and a low reference circuit.

The Camshaft Position (CMP) sensor is triggered by a notched reluctor wheel built into the exhaust camshaft sprocket. The CMP sensor provides 6 signal pulses every camshaft revolution. Each notch, or feature of the reluctor wheel is of a different size for individual cylinder identification. This means the CMP and crankshaft position (CKP) signals are pulse width encoded to enable the powertrain control module (PCM) to constantly monitor their relationship. This relationship is used to determine camshaft actuator position and control its phasing at the correct value. The PCM also uses this signal to identify the compression stroke of each cylinder, and for sequential fuel injection. The CMP sensor is connected to the PCM by a 12-volt, low reference, and signal circuit.

BUICK Related P1345 code