Inspect both front and rear bulbs and sockets. Look for signs of overheating on the contacts. Inspect for damaged wiring. Your turn signal switch (Multifunction switch) may be defective. The input from the Multifunction switch goes to a BODY CONTROL MODULE (BCM) which actuates the turn signal lamps when the input is received. The combination flasher may be operated in its hazard warning mode either with or without the ignition circuit being active. However, in order to operate in the turn signal mode, the ignition circuit must be completed to the module.
While the combination flasher is idle, there is no current drawn through the module. The device does not become active until a signal ground circuit is supplied to either of the turn signal inputs or the hazard warning input.
Typical flash rate for the flasher is 90 flashes per minute.
When a lamp is burnt out for a given side of the vehicle or a wire is open to a lamp, the flash rate will increase to 180 flashes per minute when in the turn signal mode. When in the hazard warning signal mode the flash rate remains at 90 flashes per minute.