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.

NO.10 LOW IDLE/STALLS DURING DECELERATION [BP, BP WITH TC] DIAGNOSTIC PROCEDURE

STEP	INSPECTION		ACTION
1	Does engine idle rough?	Yes	Go to flow chart 8 for "NO.8 ENGINE RUNS ROUGH/ROLLING IDLE ".
1	Does engine idle rough?	No	Go to the next step.
2	Verify following: Proper routing and no damage of vacuum lines IAC valve is properly connected. No air leakage from intake-air system Are all items okay?	Yes	Go to the next step.
2		No	Service if necessary. Repeat Step 2.
3	Connect WDS or equivalent to DLC-2. Turn ignition switch to ON. Retrieve any DTC. Is "PASSED" displayed?	Yes	No DTC displayed: Go to the next step.
3		No	DTC displayed: Go to appropriate DTC test.
4	Does idle speed drop or stall when disconnecting IAC valve?	Yes	Go to the next step.
4	Does idle speed drop or stall when disconnecting IAC valve?	No	Inspect following: Circuit from IAC valve to PCM connector terminal 2P or 2Q for open and short IAC valve for being stuck If okay, go to the next step.
5	Inspect variable valve timing operation. Is variable valve timing operation okay?	Yes	Go to next step
5		No	Repair or replace malfunctioning parts.
6	Disconnect vacuum hose between purge solenoid valve and intake manifold from purge solenoid valve side. Plug opening end of vacuum hose. Drive vehicle. Does engine condition improve?	Yes	Inspect EVAP control system.
6		No	Go to the next step.
7	Connect WDS or equivalent to DLC-2. Access TP, MAF, VSS PIDs. Monitor each PIDs while driving vehicle. (See PCM INSPECTION ) Are PIDs okay?	Yes	Go to flow chart 27 for "NO.27 INTERMITTENT CONCERNS ".
7		No	TP PID: Inspect for TP sensor. MAF PID: Inspect for MAF sensor. VSS PID: Inspect VSS.
8	Verify test results. If okay, return to diagnostic index to service any additional symptoms. If malfunction remains, inspect related Service Bulletins and/or On-line Repair Information and perform repair or diagnosis. If vehicle is repaired, troubleshooting completed. If vehicle is not repaired or additional diagnostic information is not available, replace PCM.