P0374

Timing Reference High Resolution Signal A No Pulses

Severity

🚨 Critical

Can you drive?

Do not drive — repair immediately

Approx. repair cost

$22–111 (est.)

Symptoms

Engine won't start
Unstable operation at idle
Misfire
Significant power loss
Check Engine Light Is On

Causes

Reference sensor A fault
Open or short circuit in the sensor circuit
Damage to the drive disk (ring gear)
Weak sensor fastening, incorrect gap
Distributor malfunction (for engines with distributor)

How to Fix

Read codes, determine if there are related crankshaft sensor codes
Check the sensor circuit: power, ground, signal wire
Check the air gap between the sensor and the drive disk
Inspect the drive disc teeth for damage.
Replace reference signal sensor
For distributor systems - check the distributor rotor and cap

Related codes

P0377 P0378 P0335 P0320 P0321