Check code 04

WARNING: This page is about a different car, the 2005 Mazda RX-8. However, it is still accessible from the selected car via links, so may be relevant.

CHECK CODE 04 DIAGNOSTIC PROCEDURES

Check code 04		Door switch ON/OFF signal
STEP	INSPECTION CONDITION	DISPLAY	ACTION
1	Open the front driver-side door. (The door switch is on.)	on	Close the front driver-side door, then go to the next step.
1	Open the front driver-side door. (The door switch is on.)	OFF	Verify that the voltage of the instrument cluster terminal 2E is 1.O V or less. If the voltage is as specified, replace the instrument cluster. If the voltage is not as specified, inspect the following parts: Door switch Wiring harness (Instrument cluster-door switch)
2	Close all doors. (Door switches are off.)	on	Verify that the voltage of the instrument cluster terminal 2E is B+. If the voltage is as specified, replace the instrument cluster. If the voltage is not as specified, inspect the following parts: Door switch Wiring harness (Instrument cluster-door switch)
2	Close all doors. (Door switches are off.)	OFF	Input signal to the instrument cluster is normal.