Fuel Injector Malfunction

NOTE: The following test procedures are for DTCs P0201, P0202, P0203, P0204, P0205 and P0206.

Fig 1: Identifying Fuel Injector Malfunction Detection Condition Possible Cause

Courtesy of MAZDA MOTORS CORP.

FUEL INJECTOR MALFUNCTION INSPECTION/ACTION CHART

STEP	INSPECTION		ACTION
1	PCM QUICK TEST Was PCM Quick Test performed?	Yes	Go to next step.
1	PCM QUICK TEST Was PCM Quick Test performed?	No	Perform PCM Quick Test. See PCM QUICK TEST .
2	CHECK INJECTOR FAULT PIDS Access INJ1F-INJ6F PIDs using WDS or equivalent tester. Is an injector(s) fault present?	Yes	Go to next step.
2		No	Go to step 6.
3	CHECK FUEL INJECTOR(S) AND HARNESS RESISTANCE NOTE: This erases Continuous Memory DTCs. Disconnect PCM. Disconnect PCM Power Relay. Install Breakout Box, leave PCM disconnected. NOTE: Use the injector fault PID to determine the fuel injector circuit(s) requiring testing. Measure resistance of fuel injector between suspect INJ circuit PCM test pin and PCM power relay pin 87 (R). Is the resistance between 11.0-18.0 ohms?	Yes	Replace PCM. POWERTRAIN CONTROL MODULE (PCM) . Go to step 6.
3		No	Go to next step.
4	CHECK FUEL INJECTOR HARNESS RESISTANCE Disconnect fuel injector harness connector at the suspect fuel injector. Measure resistance of circuit between PCM power relay pin 87 and the fuel injector harness connector. Measure resistance of INJ circuit between appropriate PCM test pin and the fuel injector harness connector. Is each resistance less than 5.0 ohms?	Yes	Go to next step.
4		No	Repair open harness circuit. Go to step 6.
5	CHECK FUEL INJECTOR HARNESS CIRCUIT FOR SHORT TO POWER AND GROUND Measure resistance between suspect INJ circuit PCM test pin and PCM power relay pin 87 (R). Measure resistance between suspect INJ circuit PCM test pin and PCM test pin C48 (PWR GND). Is each resistance greater than 10K ohms?	Yes	Replace PCM. POWERTRAIN CONTROL MODULE (PCM) . Repeat PCM Quick Test. See PCM QUICK TEST . Go to next step.
5		No	Repair short circuit. Go to next step.
6	VERIFY TROUBLESHOOTING OF DTCs COMPLETED Make sure to reconnect all disconnected connectors. Clear DTCs from PCM memory using WDS or equivalent tester generic OBD II function. Perform PCM Quick Test. See PCM QUICK TEST . Is same DTC present?	Yes	Replace PCM. POWERTRAIN CONTROL MODULE (PCM) . Repeat PCM Quick Test. See PCM QUICK TEST .
6		No	If any other DTC is present, go to applicable DTC inspection. If no DTC is present, troubleshooting complete.