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 P0403 [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 the FREEZE FRAME DATA on the 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, go to the next step.
2		No	Go to the next step.
3	VERIFY CURRENT SIGNAL STATUS: IS CONCERN INTERMITTENT OR CONSTANT? Connect the WDS or equivalent to the DLC-2. Clear the DTC from the PCM memory using the WDS or equivalent. Run the vehicle under the FREEZE FRAME DATA stored condition. Is the same PENDING CODE for this DTC present?	Yes	Go to the next step.
3		No	Intermittent concern exists. Perform the "INTERMITTENT CONCERNS TROUBLESHOOTING". (See INTERMITTENT CONCERN TROUBLESHOOTING .)
4	INSPECT POOR CONNECTION OF EGR VALVE Turn the ignition switch off. Disconnect EGR valve connector. Check for poor connection (damaged, pulled-out terminals, corrosion, etc.). Is there any malfunction?	Yes	Repair or replace terminals and/or connector, then go to Step 11.
4		No	Go to the next step.
5	INSPECT POWER CIRCUIT FOR OPEN CIRCUIT Turn the ignition switch to the ON position (Engine off). Measure following EGR valve power circuit terminal voltage. EGR valve terminal C and body ground EGR valve terminal D and body ground Is voltage B+ ?	Yes	Go to the next step.
5		No	Repair or replace harness for an open circuit then go to Step 11.
6	INSPECT EGR VALVE Inspect the EGR valve. Is there any malfunction?	Yes	Replace EGR valve, then go to Step 11.
6		No	Go to the next step.
7	INSPECT CONTROL CIRCUIT FOR SHORT TO POWER Turn the ignition switch to the ON position (Engine off). Measure voltage following EGR valve control circuit. EGR valve terminal E and body ground EGR valve terminal A and body ground EGR valve terminal B and body ground EGR valve terminal F and body ground Is voltage B+ ?	Yes	Repair or replace harness for short to power, then go to Step 11.
7		No	Go to the next step.
8	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 11.
8		No	Go to the next step.
9	INSPECT CONTROL CIRCUIT FOR SHORT TO GROUND Turn the ignition switch off. Check continuity following EGR valve control circuit. EGR valve terminal E and body ground EGR valve terminal A and body ground EGR valve terminal B and body ground EGR valve terminal F and body ground Is there continuity?	Yes	Repair or replace harness for short to ground, then go to Step 11.
9		No	Go to the next step.
10	INSPECT CONTROL CIRCUIT FOR OPEN CIRCUIT Check continuity following EGR control circuit. EGR valve terminal E and PCM terminal 2E (harness-side) EGR valve terminal A and PCM terminal 2F (harness-side) EGR valve terminal B and PCM terminal 2H (harness-side) EGR valve terminal F and PCM terminal 2I (harness-side) Is there continuity?	Yes	Go to the next step.
10		No	Repair or replace harness for an open circuit then go to Step 11
11	VERIFY TROUBLESHOOTING OF DTC P0403 COMPLETED Make sure to reconnect all disconnected connectors. Turn the ignition switch off then to the ON position (Engine off). Clear the DTC from the PCM memory using the WDS or equivalent. Start the engine. Is same PENDING CODE for this DTC present?	Yes	Replace PCM, then go to the next step.
11		No	Go to the next step.
12	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 .)
12		No	Troubleshooting completed.