Diagnostic procedure

WARNING: This page is about a different car, the 2005 Mazda MX-5 Miata. However, it is still accessible from the selected car via links, so may be relevant.

DTC P2503 [BP, BP WITH TC] DIAGNOSTIC PROCEDURE

STEP	INSPECTION		ACTION
1	VERIFY FREEZE FRAME DATA HAS BEEN RECORDED Has FREEZE FRAME DATA been recorded?	Yes	Go to the next step.
1		No	Record FREEZE FRAME DATA on repair order, then go to the next step.
2	VERIFY RELATED REPAIR INFORMATION AVAILABILITY Check for related Service Bulletins and/or online 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, then go to the next step.
2		No	Go to the next step.
3	INSPECT DRIVE BELT CONDITION Verify that drive belt auto tensioner indicator mark does not exceed limit. Is front drive belt okay?	Yes	Go to the next step.
3		No	Replace and/or adjust drive belt, then go to Step 10.
4	INSPECT PCM CONNECTOR FOR POOR CONNECTION Turn the ignition switch off. Disconnect PCM connector. Inspect for poor connection (such as damaged/ pulled-out pins, corrosion). Is there a malfunction?	Yes	Repair terminals, then go to Step 10.
4		No	Go to the next step.
5	INSPECT GENERATOR CONNECTOR FOR POOR CONNECTION Disconnect generator connector. Inspect for poor connection (such as damaged/ pulled-out pins, corrosion). Is there a malfunction?	Yes	Repair or replace terminals, then go to Step 10.
5		No	Go to the next step.
6	INSPECT GENERATOR CONTROL CIRCUIT FOR SHORT TO GROUND Inspect for continuity between generator terminal D (harness-side) and body ground. Is there continuity?	Yes	Repair or replace harness for short to ground, then go to Step 10.
6		No	Go to the next step.
7	INSPECT GENERATOR OUTPUT VOLTAGE MONITOR CIRCUIT FOR SHORT TO GROUND Inspect for continuity between generator terminal P (harness-side) and body ground. Is there continuity?	Yes	Repair or replace harness for short to ground, then go to Step 10.
7		No	Go to the next step.
8	INSPECT GENERATOR CONTROL CIRCUIT FOR OPEN CIRCUIT Measure resistance between generator terminal D (harness-side) and PCM terminal 3M (harness-side). Is there continuity?	Yes	Go to the next step.
8		No	Repair or replace harness for an open circuit, then go to Step 10.
9	INSPECT GENERATOR OUTPUT VOLTAGE MONITOR CIRCUIT FOR OPEN CIRCUIT Measure resistance between generator terminal P (harness-side) and PCM terminal 4T (harness-side). Is there continuity?	Yes	Repair or replace generator, then go to the next step.
9		No	Repair or replace harness for an open circuit, then go to the next step.
10	VERIFY TROUBLESHOOTING OF DTC P2503 COMPLETED Make sure to reconnect all connectors. Clear the DTC from the PCM memory using the WDS or equivalent. Turn the ignition switch off, then start engine. Is the same DTC present?	Yes	Replace PCM, then go to the next step.
10		No	Go to the next step.
11	VERIFY AFTER REPAIR PROCEDURE Perform the "AFTER REPAIR PROCEDURE ". (See AFTER REPAIR PROCEDURE .) Is any DTC present?	Yes	Go to the applicable DTC inspection. (See DTC TABLE .)
11		No	Troubleshooting completed.