Diagnostic procedure

DTC P2257 DIAGNOSTIC PROCEDURE CHART

STEP	INSPECTION		ACTION
1	VERIFY FREEZE FRAME DATA AND DIAGNOSTIC MONITORING TEST RESULTS HAVE BEEN RECORDED Have FREEZE FRAME DATA and DIAGNOSTIC MONITORING TEST RESULTS (AIR system related) been recorded?	Yes	Go to the next step.
1		No	Record the FREEZE FRAME DATA and DIAGNOSTIC MONITORING TEST RESULTS on the repair order, then go to the next step.
2	VERIFY RELATED REPAIR INFORMATION AVAILABILITY Verify related Service Bulletins and/or on-line repair information availability. Is any related repair information available?	Yes	Perform repair or diagnosis according to the available repair information. If the vehicle is not repaired, go to the next step.
2		No	Go to the next step.
3	INSPECT AIR PUMP RELAY CONNECTOR FOR POOR CONNECTION Turn the ignition switch off. Disconnect the AIR pump relay connector. Inspect for poor connection (such as damaged/pulled-out pins, corrosion). Is there any malfunction?	Yes	Repair or replace the terminal, then go to Step 9.
3		No	Go to the next step.
4	INSPECT AIR PUMP RELAY POWER CIRCUIT FOR OPEN CIRCUIT OR SHORT TO GROUND Turn the ignition switch to the ON position (Engine off). Measure the voltage between AIR pump relay terminal E (wiring harness-side) and body ground. Is the voltage B+?	Yes	Go to the next step.
4		No	Repair or replace the wiring harness for a possible open circuit or short to ground, then go to Step 9.
5	INSPECT AIR PUMP RELAY CONTROL CIRCUIT FOR SHORT TO GROUND Turn the ignition switch off. Inspect for continuity between AIR pump relay terminal A (wiring harness-side) and body ground. Is there continuity?	Yes	Repair or replace the wiring harness for a possible short to ground, then go to Step 9.
5		No	Go to the next step.
6	INSPECT AIR PUMP RELAY Inspect the AIR pump relay. (See RELAY INSPECTION ) Is there any malfunction?	Yes	Replace the AIR pump relay, then go to Step 9. (See RELAY LOCATION )
6		No	Go to the next step.
7	INSPECT PCM CONNECTOR FOR POOR CONNECTION Turn the ignition switch off. Disconnect the PCM connector. Inspect for poor connection (such as damaged/pulled-out pins, corrosion). Is there any malfunction?	Yes	Repair or replace the terminal, then go to Step 9.
7		No	Go to the next step.
8	INSPECT AIR PUMP RELAY CONTROL CIRCUIT FOR OPEN CIRCUIT Turn the ignition switch off. Inspect for continuity between AIR pump relay terminal A (wiring harness-side) and PCM terminal 4O (wiring harness-side). Is there continuity?	Yes	Go to the next step.
8		No	Repair or replace the wiring harness for a possible open circuit, then go to the next step.
9	VERIFY TROUBLESHOOTING OF DTC P2257 COMPLETED Make sure to reconnect all disconnected connectors. Clear the DTC from the PCM memory using the M-MDS or equivalent. Start the engine. Is the PENDING CODE same as DTC present?	Yes	Replace the PCM, then go to the next step. (See PCM REMOVAL/INSTALLATION )
9		No	Go to the next step.
10	VERIFY AFTER REPAIR PROCEDURE Perform the AFTER REPAIR PROCEDURE . Are any DTCs present?	Yes	Go to the applicable DTC inspection. (See DTC TABLE ).
10		No	DTC troubleshooting completed.