Mazda Factory OBD-II DTC U0001, U0073, U2012, U2516 Code Diagnostic Procedure

TC	Mazda U0001	PCM (MZ-CD 1.6 (Y6))
	Mazda U0073	PCM (except MZ-CD 1.6 (Y6)) TCM (FS5A-EL) EHPAS control module Keyless control module Instrument cluster
	Mazda U2012	DSC HU/CM ABS HU/CM
	Mazda U2516	Fuel additive control module (MZ-CD 1.6 (Y6) High power-Euro 4 only)
DETECTION CONDITION		Warning • Detection conditions are for understanding the DTC outline before performing an inspection. Performing an inspection according to only detection conditions may cause injury due to operating error, or damage the system. When performing an inspection, always follow the inspection procedure. • CAN system related harness malfunction • Related module communication error
POSSIBLE CAUSE		• Open or short circuit in wiring harness • Malfunction of connectors between PCM, TCM, EHPAS control module, DSC HU/CM, ABS HU/CM, fuel additive control module, keyless control module and instrument cluster • PCM malfunction • TCM malfunction • Fuel additive control module malfunction • EHPAS control module malfunction • DSC HU/CM or ABS HU/CM malfunction • Keyless control module malfunction • Instrument cluster malfunction

Diagnostic procedure

STEP	INSPECTION		ACTION
1	INSPECT CAN SYSTEM-RELATED DTC • Are any DTCs other than the following displayed? ― U0001 ― U0073 ― U2012 ― U2516	Yes	Determine malfunctioning part in CAN system.
1		No	Go to the next step.
2	INSPECT CONNECTOR • Inspect the connector of the module that outputs the DTC. • Is it normal?	Yes	Go to the next step.
2		No	Repair or replace the connector, then go to Step 4.
3	INSPECT WIRING HARNESSES • Inspect for the following malfunctioning wiring harnesses: ― Short to GND ― Short to power supply ― Twisted pair short each other ― Open circuit • Is there any malfunction?	Yes	Repair or replace the wiring harness, then go to the next step.
3		No	Go to the next step.
4	VERIFY TROUBLESHOOTING COMPLETED • Make sure to reconnect all disconnected connectors. • Clear the DTC using the M-MDS. • Is the same DTC present?	Yes	Replace the module that outputs the DTC, then retry this step.
4		No	Troubleshooting completed.