Symptom Troubleshooting [Engine Control System [Mzr 2.5]]: Diagnosis

SYMPTOM DIAGNOSTIC INDEX [MZR 2.5]

Confirm trouble symptom using the following diagnostic index, then go to appropriate troubleshooting chart.

Diagnostic Index

No.	TROUBLESHOOTING ITEM		DESCRIPTION
1	Melting of main or other fuses
2	MIL illuminates		MIL is illuminated incorrectly.
3	Will not crank		Starter does not work.
4	Hard to start/long crank/erratic start/erratic crank		Starter cranks engine at normal speed but engine requires excessive cranking time before starting.
5	Engine stalls	After start/at idle	Engine stops unexpectedly at idle and/or after start.
6	Cranks normally but will not start		Starter cranks engine at normal speed but engine will not run.
7	Slow return to idle		Engine takes more time than normal to return to idle speed.
8	Engine runs rough/rolling idle		Engine speed fluctuates between specified idle speed and lower speed and engine shakes excessively. Idle speed is too slow and engine shakes excessively.
9	Fast idle/runs on		Engine speed continues at fast idle after warm-up. Engine runs after ignition is off.
10	Low idle/stalls during deceleration		Engine stops unexpectedly at beginning of deceleration or recovery from deceleration.
11	Engine stalls/quits	Acceleration/cruise	Engine stops unexpectedly at beginning of acceleration or during acceleration. Engine stops unexpectedly while cruising.
	Engine runs rough	Acceleration/cruise	Engine speed fluctuates during acceleration or cruising.
	Misses	Acceleration/cruise	Engine misses during acceleration or cruising.
	Buck/jerk	Acceleration/cruise/deceleration	Vehicle bucks/jerks during acceleration, cruising, or deceleration.
	Hesitation/stumble	Acceleration	Momentary pause at beginning of acceleration or during acceleration.
	Surges	Acceleration/cruise	Momentary minor irregularity in engine output.
12	Lack/loss of power	Acceleration/cruise	Performance is poor under load. (e.g. power down when climbing hills)
13	Knocking/pinging	Acceleration/cruise	Sound is produced when air/fuel mixture is ignited by something other than spark plug. (e.g. hot spot in combustion chamber)
14	Poor fuel economy		Fuel economy is unsatisfactory.
15	Emission compliance		Fails emissions test.
16	High oil consumption/leakage		Oil consumption is excessive.
17	Cooling system concerns	Overheating	Engine runs at higher than normal temperature/overheats.
18	Cooling system concerns	Runs cold	Engine takes excessive time to reach normal operating temperature.
19	Exhaust smoke		Blue, black, or white smoke from exhaust system.
20	Fuel odor (in engine compartment)		Gasoline fuel smell or visible leakage.
21	Engine noise		Engine noise from under hood.
22	Vibration concerns (engine)		Vibration from under hood or driveline.
23	A/C does not work sufficiently		A/C compressor magnetic clutch does not engage when A/C is turned on.
24	A/C is always on or A/C compressor runs continuously		A/C compressor magnetic clutch does not disengage.
25	A/C is not cut off under WOT conditions		A/C compressor magnetic clutch does not disengage under WOT.
26	Exhaust sulphur smell		Rotten egg smell (sulphur) from exhaust.
27	Fuel refill concerns		Fuel tank does not fill smoothly.
28	Fuel filling shut off concerns		Fuel does not shut off properly.
29	Spark plug condition		Incorrect spark plug condition.
30	ATX concerns	Upshift/downshift/engagement	ATX concerns not related to engine performance.

Scheme 51

Scheme 51: CONTROL SYSTEM DEVICE AND CONTROL RELATIONSHIP CHART [MZR 2.5]

Scheme 52

Scheme 52: QUICK DIAGNOSTIC CHART [MZR 2.5]

*1 Without advanced keyless entry and push button start system

*2 With advanced keyless entry and push button start system

Scheme 53

Scheme 54

Scheme 55

Scheme 56

Scheme 57

Diagnostic Procedure

STEP	INSPECTION	RESULTS	ACTION
1	VERIFY PCM DTC Retrieve any DTCs using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZR 2.5] .) Are there any DTCs displayed?	Yes	Go to the appropriate DTC inspection. (See DTC TABLE [MZR 2.5] .)
1		No	Inspect the instrument cluster operation. (See INSTRUMENT CLUSTER INSPECTION .)
2	Verify test results. If normal, return to diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [MZR 2.5] .) 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, reprogram the PCM if a later calibration is available. Retest.

STEP	INSPECTION	RESULTS	ACTION
1	DETERMINE IF MALFUNCTION CAUSE IS ADVANCED KEYLESS ENTRY AND PUSH BUTTON START SYSTEM OR OTHER NOTE: The following test should be performed on the advanced keyless entry and push button start system. If not equipped, go to the next step. Insert the emergency key in the emergency slot and start the engine. Does the engine start?	Yes	Inspect the advanced keyless entry and push button start system and repair or replace according to the inspection result. (See SYMPTOM TROUBLESHOOTING CHART [ADVANCED KEYLESS ENTRY AND PUSH BUTTON START SYSTEM] .)
1		No	Go to the next step.
2	DETERMINE IF MALFUNCTION CAUSE IS IMMOBILIZER SYSTEM OR OTHER Do the following conditions appear? Engine does not start completely. PCM DTC P1260:00 is displayed.	Yes	Both conditions appear: Go to Step 5.
2		No	Either condition or other one appears: Go to the next step.
3	INSPECT COIL ANTENNA CONNECTOR CONNECTION Is the coil antenna connector securely connected to the coil antenna?	Yes	Go to the next step.
3		No	Connect the coil antenna connector securely. Return to Step 1.
4	DETERMINE IF MALFUNCTION CAUSE IS INSTRUMENT CLUSTER OR OTHER Does the security light flash?	Yes	Go to the next step.
4		No	Inspect the instrument cluster and wiring harness. (See INSTRUMENT CLUSTER INSPECTION .) Repair or replace the malfunctioning part according to the inspection results.
5	VERIFY IMMOBILIZER SYSTEM DTC Retrieve the DTC for the immobilizer system. (See DTC INSPECTION [IMMOBILIZER SYSTEM (KEYLESS ENTRY SYSTEM)] .) (See DTC INSPECTION [IMMOBILIZER SYSTEM (ADVANCED KEYLESS ENTRY AND PUSH BUTTON START SYSTEM)] .) Is there any DTC present?	Yes	Go to the appropriate DTC inspection. (See DTC TABLE [IMMOBILIZER SYSTEM (KEYLESS ENTRY SYSTEM)] .) (See DTC TABLE [IMMOBILIZER SYSTEM (ADVANCED KEYLESS ENTRY AND PUSH BUTTON START SYSTEM)] .)
5		No	Go to the next step.
6	INSPECT IMMOBILIZER SYSTEM RELATED CIRCUIT Inspect the following wiring harnesses and connectors: With advanced keyless entry and push button start system: Between coil antenna terminal C and keyless control module terminal 2B Between coil antenna terminal D and keyless control module terminal 2D Between PCM terminal 1AM and keyless control module terminal 2G Between PCM terminal 1AI and keyless control module terminal 2I Without advanced keyless entry and push button start system: Between coil antenna terminal C and instrument cluster terminal 2E Between coil antenna terminal D and instrument cluster terminal 2G Between PCM terminal 1AM and instrument cluster terminal 2X Between PCM terminal 1AI and instrument cluster terminal 2W Is there any malfunction?	Yes	Repair or replace suspected wiring harness and connector.
6		No	Go to the next step.
7	INSPECT POWER SUPPLY Inspect the following: Battery connection Battery condition (See BATTERY INSPECTION [MZR 2.5] .) Fuses (See NO.1 MELTING OF MAIN OR OTHER FUSES [MZR 2.5] .) Selector lever is in P or N position (ATX) Are all items normal?	Yes	With advanced keyless entry and push button start system: Go to the next step. Without advanced keyless entry and push button start system: Go to Step 19.
7		No	Service if necessary. Repeat Step 7.
8	INSPECT STARTER RELAY Inspect the starter relay. (See RELAY INSPECTION .) Is the starter relay normal?	Yes	Go to the next step.
8		No	Replace the starter relay.
9	DETERMINE IF MALFUNCTION CAUSE IS STARTER RELAY PRIMARY COIL POWER SUPPLY OR OTHER Remove the starter relay. Measure the voltage of the connector terminal (primary coil power supply) on the starter relay wiring harness while cranking. Is the voltage B+ ?	Yes	Go to Step 12.
9		No	Go to the next step.
10	INSPECT STARTER RELAY PRIMARY COIL POWER SUPPLY CIRCUIT FOR OPEN CIRCUIT Switch the ignition to off Disconnect the keyless control module connector. Verify continuity between keyless control module terminal 4B and starter relay terminal (primary coil power supply). Is there continuity?	Yes	Go to the next step.
10		No	Repair or replace suspected wiring harness and connector.
11	INSPECT STARTER RELAY PRIMARY COIL POWER SUPPLY CIRCUIT FOR SHORT TO GROUND Verify continuity between keyless control module terminal 4B and body ground. Is there continuity?	Yes	Repair or replace suspected wiring harness and connector.
11		No	Replace the keyless control module. (See KEYLESS CONTROL MODULE REMOVAL/INSTALLATION [ADVANCED KEYLESS ENTRY AND PUSH BUTTON START SYSTEM] .)
12	DETERMINE IF MALFUNCTION CAUSE IS TR SWITCH (ATX)/STARTER INTERLOCK SWITCH (MTX) OR OTHER Install the starter relay. MTX: Short the terminals of the starter interlock switch connector (2-pin) using a jumper wire. ATX: Short TR switch terminals A and F using a jumper wire. Switch the ignition to start. Does the engine start?	Yes	MTX: Replace the starter interlock switch. ATX: Replace the TR switch. (See TRANSAXLE RANGE (TR) SWITCH REMOVAL/INSTALLATION [FS5A-EL] .)
12		No	Go to the next step.
13	DETERMINE IF MALFUNCTION CAUSE IS STARTER RELAY CONTROL CIRCUIT OR OTHER Is the starter relay operation sound heard when the engine starting procedure is performed in Step 12?	Yes	Go to the next step.
13		No	Go to Step 17.
14	INSPECT STARTER MONITOR SIGNAL CIRCUIT Switch the ignition to off Measure the voltage at keyless control module terminal 4AA. Is the voltage specified? Specification MTX: Clutch pedal is not depressed: 1.0 V or less Clutch pedal is depressed: 4.0 V or more ATX: Shift position is not P or N position: 1.0 V or less Shift position is P or N position: 4.0 V or more	Yes	Go to the next step.
14		No	Repair or replace suspected wiring harness and connector.
15	INSPECT SHIFT POSITION (ATX)/CLUTCH PEDAL POSITION (MTX) MONITOR SIGNAL CIRCUIT Switch the ignition to off. Disconnect the keyless control module, starter interlock switch (MTX)/TR switch (ATX) connectors. Verify continuity between the following terminals: MTX: Between keyless control module terminal 4K and starter interlock switch ATX: Between keyless control module terminal 4K and TR switch terminal F Is there continuity?	Yes	Go to the next step.
15		No	Repair or replace suspected wiring harness and connector.
16	INSPECT STARTER AND STARTER POWER SUPPLY CIRCUIT AND GROUND CIRCUIT Inspect the following: Starter (See STARTER INSPECTION [MZR 2.5] .) Starter ground (installation) Starter power supply (from battery through secondary starter relay, to starter) Is there any malfunction?	Yes	Repair or replace the malfunctioning part according to the inspection results.
16		No	Replace the keyless control module. (See KEYLESS CONTROL MODULE REMOVAL/INSTALLATION [ADVANCED KEYLESS ENTRY AND PUSH BUTTON START SYSTEM] .)
17	INSPECT SHIFT POSITION (ATX)/CLUTCH PEDAL POSITION (MTX) MONITOR SIGNAL CIRCUIT Switch the ignition to off. Disconnect the keyless control module, starter interlock switch (MTX)/TR switch (ATX) connectors. Verify continuity between the following terminals: MTX: Between keyless control module terminal 4K and starter interlock switch ATX: Between keyless control module terminal 4K and TR switch terminal F Is there continuity?	Yes	Go to the next step.
17		No	Repair or replace suspected wiring harness and connector.
18	INSPECT STARTER RELAY CONTROL SIGNAL CIRCUIT Verify continuity between the following terminals: MTX: Between starter interlock switch and PCM terminal 1BB ATX: Between TR switch terminal F and PCM terminal 1BB Is there continuity?	Yes	Go to Step 27.
18		No	Repair or replace suspected wiring harness and connector.
19	DETERMINE IF MALFUNCTION CAUSE IS STARTER RELAY CONTROL CIRCUIT OR OTHER Is there continuity between PCM terminal 1BB and starter relay with P or N position (ATX)/clutch pedal depressed (MTX)?	Yes	Go to the next step.
19		No	Repair or replace suspected wiring harness and connector.
20	DETERMINE IF MALFUNCTION CAUSE IS TR SWITCH (ATX)/STARTER INTERLOCK SWITCH (MTX) OR OTHER ATX: Selector lever is in P or N position. MTX: Depress the clutch pedal. Is a clicking sound heard from the starter relay when the switch the ignition to start?	Yes	Go to Step 25.
20		No	ATX: Go to the next step. MTX: Go to Step 22.
21	INSPECT TR SWITCH SIGNAL Access the PCM PID TR using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZR 2.5] .) Is the TR PID indicated P/N when selecting the P or N position?	Yes	Go to Step 23.
21		No	Verify that the TR switch is adjusted properly. Inspect for an open or short circuit between TR switch and TCM. Repair or replace the malfunctioning part according to the inspection results. Repeat Step 20.
22	INSPECT STARTER INTERLOCK SWITCH Inspect the starter interlock switch. (See STARTER INTERLOCK SWITCH INSPECTION [MZR 2.5] .) Is the starter interlock switch normal?	Yes	Go to the next step.
22		No	Inspect the starter interlock switch and related wiring harnesses. Repair or replace the malfunctioning part according to the inspection results. Repeat Step 20.
23	INSPECT STARTER RELAY CONTROL CIRCUIT Inspect the starter relay and the following wiring harnesses: (See RELAY INSPECTION .) Between starter relay and PCM Between starter relay and ignition switch Are they normal?	Yes	Go to the next step.
23		No	Repair or replace the malfunctioning part according to the inspection results. Repeat Step 20.
24	INSPECT IGNITION SWITCH AND RELATED CIRCUIT Inspect the ignition switch and related wiring harnesses. (See IGNITION SWITCH INSPECTION [WITHOUT ADVANCED KEYLESS ENTRY AND PUSH BUTTON START SYSTEM] .) Are they normal?	Yes	Go to the next step.
24		No	Repair or replace the malfunctioning part according to the inspection results. Repeat Step 20.
25	INSPECT WIRING HARNESS OF STARTER POWER SUPPLY CIRCUIT Inspect the following wiring harnesses: Between starter relay and battery. Between starter relay and starter. Are they normal?	Yes	Go to the next step.
25		No	Repair or replace the malfunctioning part according to the inspection results. Go to the next step.
26	INSPECT STARTER AND GROUND CIRCUIT Inspect the following: Starter (See STARTER INSPECTION [MZR 2.5] .) Starter ground (installation) Starter power supply (from battery through secondary starter relay, to starter) Is there any malfunction?	Yes	Repair or replace the malfunctioning part according to the inspection results.
26		No	Go to the next step.
27	DETERMINE IF MALFUNCTION CAUSE IS BASE ENGINE OR OTHER Inspect for a seized/hydro locked engine or flywheel (MTX) or drive plate (ATX). Is the engine seized or hydro locked?	Yes	Go to the next step.
27		No	Repair or replace the malfunctioning part according to the inspection results.
28	VERIFY PCM DTC Retrieve any continuous memory DTCs. (See ON-BOARD DIAGNOSTIC TEST [MZR 2.5] .) Are there any continuous memory DTCs displayed?	Yes	DTC is displayed: Go to the appropriate DTC inspection. (See DTC TABLE [MZR 2.5] .) Communication error message is displayed: Inspect the following: Open circuit in the wiring harness between main relay terminal B and PCM terminal 1Q Open circuit in the wiring harness between main relay terminal D and PCM terminal 1A, 1B Main relay is stuck open. Open or short circuit in the wiring harness between DLC-2 and PCM terminals 1AM or 1AI Open or poor ground circuit (PCM terminal 1E,1F,1G, 1BE, or 1BF) Poor connection of vehicle body ground Repair or replace the malfunctioning part according to the inspection results.
28		No	Go to the next step.
29	VERIFY PRESENT MALFUNCTION DTC Retrieve any KOEO DTCs using the M-MDS. (See KOEO/KOER SELF TEST [MZR 2.5] .) Are there DTCs displayed during the KOEO self test?	Yes	Go to the appropriate DTC inspection. (See DTC TABLE [MZR 2.5] .)
29		No	Inspect the following: Start circuit in ignition switch Open circuit in wiring harness between ignition switch and starter Repair or replace the malfunctioning part according to the inspection results.
30	Verify test results. If normal, return to the diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [MZR 2.5] .) If a malfunction remains, inspect the related Service Bulletins and/or On-line Repair Information and perform repair or diagnosis. If the vehicle is repaired, troubleshooting is completed. If the vehicle is not repaired or additional diagnostic information is not available, reprogram the PCM if a later calibration is available. Retest.

NOTE
The following test should be performed on the advanced keyless entry and push button start system. If not equipped, go to the next step. Insert the emergency key in the emergency slot and start the engine. Does the engine start?

STEP	INSPECTION	RESULTS	ACTION
1	INSPECT RELATED PART CONDITION Inspect the following: Vacuum leakage Proper fuel quality (such as proper octane, contamination, winter/summer blend) Loose bands on intake air system Cracks on intake air system parts Intake air system restriction (such as air cleaner element, fresh air duct) Low or dead battery Charging system Are all items normal?	Yes	Go to the next step.
1		No	Repair or replace the malfunctioning part according to the inspection results. Repeat Step 1.
2	VERIFY PCM DTC Retrieve any DTCs using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZR 2.5] .) Are there any DTCs displayed?	Yes	Go to the appropriate DTC inspection. (See DTC TABLE [MZR 2.5] .)
2		No	Go to the next step.
3	VERIFY IF MALFUNCTION CAUSE IS OVERHEATING Is the engine overheating?	Yes	Go to the symptom troubleshooting "NO.17 COOLING SYSTEM CONCERNS-OVERHEATING". (See NO.17 COOLING SYSTEM CONCERNS-OVERHEATING [MZR 2.5] .)
3		No	Go to the next step.
4	DETERMINE IF MALFUNCTION CAUSE IS EVAP CONTROL SYSTEM OR OTHER Disconnect the vacuum hose from purge solenoid valve and plug opening end of vacuum hose. Start the engine. Is the starting condition improved?	Yes	Inspect if the purge solenoid valve is stuck open. Repair or replace the malfunctioning part according to the inspection results.
4		No	Go to the next step.
5	INSPECT MAF SENSOR Inspect the MAF sensor for following: Contamination MAF sensor terminal B voltage (ground circuit) Is there any malfunction?	Yes	Repair or replace the malfunctioning part according to the inspection results.
5		No	Go to the next step.
6	INSPECT PCM FOR POOR GROUND Verify the PCM ground point condition. Is there any ground point looseness or lifting in the PCM?	Yes	Repair the ground point looseness and lifting.
6		No	Go to the next step.
7	INSPECT IGNITION SYSTEM RELATED WIRING HARNESS Inspect the ignition coil related wiring harness condition (intermittent open or short circuit) for all cylinders. Are the wiring harness conditions normal?	Yes	Go to the next step.
7		No	Repair or replace suspected wiring harness and connector.
8	INSPECT IGNITION SYSTEM OPERATION Perform the Spark Test. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZR 2.5] .) Is a strong blue spark visible at each cylinder?	Yes	Go to the next step.
8		No	Repair or replace the malfunctioning part according to the inspection results.
9	VERIFY SPARK PLUG CONDITION Verify the spark plug conditions when the spark plug removed in Step 8. (See SPARK PLUG INSPECTION [MZR 2.5] .) Is spark plug wet, covered with carbon or grayish white?	Yes	Spark plug is wet or covered with carbon: Inspect for fuel leakage from fuel injector. Spark plug is grayish white: Inspect the fuel injector for clogging. Repair or replace the malfunctioning part according to the inspection results.
9		No	Install the spark plugs on original cylinders. Go to the next step.
10	INSPECT CKP SENSOR AND PULSE WHEEL Visually inspect the CKP sensor and teeth of crankshaft pulley. Are the CKP sensor and teeth of crankshaft pulley normal?	Yes	Go to the next step.
10		No	Repair or replace the malfunctioning part according to the inspection results.
11	DETERMINE IF MALFUNCTION CAUSE IS DRIVE-BY-WIRE CONTROL SYSTEM OR OTHER Attempt to start the engine at part throttle. Does the engine run smoothly at part throttle?	Yes	Inspect the drive-by-wire control system operation. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZR 2.5] .) Repair or replace the malfunctioning part according to the inspection results.
11		No	Go to the next step.
12	INSPECT FUEL LINE PRESSURE Inspect the fuel line pressure. (See FUEL LINE PRESSURE INSPECTION [MZR 2.5] .) Is the fuel line pressure correct?	Yes	Go to the next step.
12		No	Zero or low: Inspect the following: Fuel pump relay Fuel pump circuit Fuel line for clogging If there is no malfunction, replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [MZR 2.5] .) High: Replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [MZR 2.5] .)
13	INSPECT FUEL LINE HOLD PRESSURE FOR FUEL LEAKAGE Is the fuel line pressure held after ignition is off? (See FUEL LINE PRESSURE INSPECTION [MZR 2.5] .)	Yes	Go to the next step.
13		No	Inspect the fuel injector. (See FUEL INJECTOR INSPECTION [MZR 2.5] .) If the fuel injector is normal, replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [MZR 2.5] .)
14	INSPECT EXHAUST SYSTEM Visually inspect the exhaust system part. Is there any deformed exhaust system part?	Yes	Repair or replace the malfunctioning part according to the inspection results.
14		No	Go to the next step.
15	INSPECT EGR VALVE FOR STUCK Inspect the engine condition while tapping the EGR valve housing. Does the engine condition improve?	Yes	Replace the EGR valve. (See EGR VALVE REMOVAL/INSTALLATION [MZR 2.5] .)
15		No	Go to the next step.
16	INSPECT STARTING SYSTEM Inspect the starting system. (See STARTER INSPECTION [MZR 2.5] .) Is the starting system normal?	Yes	Inspect for loose connectors or poor terminal contact. If there is no malfunction, remove the EGR valve and visually inspect for a mechanically stuck EGR valve.
16		No	Repair or replace the malfunctioning part according to the inspection results.
17	Verify test results. If normal, return to the diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [MZR 2.5] .) If a malfunction remains, inspect the related Service Bulletins and/or On-line Repair Information and perform repair or diagnosis. If the vehicle is repaired, troubleshooting is completed. If the vehicle is not repaired or additional diagnostic information is not available, reprogram the PCM if a later calibration is available. Retest.

STEP	INSPECTION	RESULTS	ACTION
1	INSPECT RELATED PART CONDITION Inspect the following: Vacuum connection Air cleaner element No air leakage from intake air system No restriction of intake air system Proper sealing of intake manifold and components attached to intake manifold EGR valve Ignition wiring Fuel quality: proper octane, contamination, winter/summer blend Electrical connections Smooth operation of throttle valve Are all items normal?	Yes	Go to the next step.
1		No	Repair or replace the malfunctioning part according to the inspection results. Repeat Step 1.
2	INSPECT APP SENSOR SIGNAL Access the PCM PIDs APP1 and APP2 using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZR 2.5] .) Crank the engine with the accelerator pedal released. Are the APP1 and APP2 PIDs indicating that the accelerator pedal is in the released position?	Yes	Go to the next step.
2		No	Inspect the following: APP sensor (See ACCELERATOR PEDAL POSITION (APP) SENSOR INSPECTION [MZR 2.5] .) Wiring harness and connector for the following: APP sensor terminal A-PCM terminal 1W APP sensor terminal B-PCM terminal 1AP APP sensor terminal C-PCM terminal 1AV APP sensor terminal D-PCM terminal 1AS APP sensor terminal E-PCM terminal 1AO APP sensor terminal F-PCM terminal 1AL Repair or replace the malfunctioning part according to the inspection results.
3	INSPECT TP SENSOR SIGNAL Access the PCM PID TP REL using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZR 2.5] .) Crank the engine with the accelerator pedal released. Is the TP REL PID indicating that the accelerator pedal is in the released position?	Yes	Go to the next step.
3		No	Inspect the following: TP sensor (See THROTTLE POSITION (TP) SENSOR INSPECTION [MZR 2.5] .) Wiring harness and connector for the following: TP sensor terminal A-PCM terminal 2AK TP sensor terminal B-PCM terminal 2AO TP sensor terminal C-PCM terminal 2AL TP sensor terminal D-PCM terminal 2AP Repair or replace the malfunctioning part according to the inspection results.
4	VERIFY PRESENT MALFUNCTION DTC Retrieve any continuous memory, KOEO and KOER DTCs using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZR 2.5] .) (See KOEO/KOER SELF TEST [MZR 2.5] .) If the engine stalls, retrieve the continuous memory and KOEO DTCs. Are there any DTCs displayed?	Yes	DTC is displayed: Go to the appropriate DTC inspection. (See DTC TABLE [MZR 2.5] .) Communication error message is displayed: Inspect the following: Open circuit in the wiring harness between main relay terminal B and PCM terminal 1Q Open circuit in the wiring harness between main relay terminal D and PCM terminal 1A, 1B Main relay is stuck open. Open or short circuit in the wiring harness between DLC-2 and PCM terminals 1AM or 1AI Open or poor ground circuit (PCM terminal 1E,1F,1G, 1BE, or 1BF) Poor connection of vehicle body ground Repair or replace the malfunctioning part according to the inspection results.
4		No	Go to the next step.
5	DETERMINE IF MALFUNCTION CAUSE IS DRIVE-BY-WIRE CONTROL SYSTEM OR OTHER Attempt to start the engine at part throttle. Does the engine run smoothly at part throttle.	Yes	Inspect the drive-by-wire control system operation. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZR 2.5] .) Repair or replace the malfunctioning part according to the inspection results.
5		No	Go to the next step.
6	DETERMINE IF MALFUNCTION CAUSE IS CKP SENSOR WIRING HARNESS OR OTHER Access the PCM PID RPM using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZR 2.5] .) Is the RPM PID indicating the engine speed during engine cranking?	Yes	Go to the next step.
6		No	Inspect the following: Open or short circuit in CKP sensor Open or short circuit between CKP sensor terminal A and ground Open or short circuit between CKP sensor terminal B and PCM terminal 2W Open or short circuit between CKP sensor terminal C and PCM terminal 2AQ Repair or replace the malfunctioning part according to the inspection results. If the CKP sensor and wiring harness are normal, go to the next step.
7	VISUALLY INSPECT CKP SENSOR AND PULSE WHEEL Visually inspect the CKP sensor and teeth of the crankshaft pulley. Are the CKP sensor and teeth of the crankshaft pulley normal?	Yes	Go to the next step.
7		No	Repair or replace the malfunctioning part according to the inspection results.
8	INSPECT IGNITION SYSTEM RELATED WIRING HARNESS Inspect the ignition coil related wiring harness condition (intermittent open or short circuit) for all cylinders. Are the wiring harness conditions normal?	Yes	Go to the next step.
8		No	Repair or replace suspected wiring harness and connector.
9	INSPECT IGNITION SYSTEM OPERATION Perform the Spark Test. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZR 2.5] .) Is a strong blue spark visible at each cylinder?	Yes	Go to the next step. If a symptom occurs with the A/C on, go to Step 15.
9		No	Repair or replace the malfunctioning part according to the inspection results.
10	VERIFY SPARK PLUG CONDITION Verify the spark plug conditions when the spark plug removed in Step 9. (See SPARK PLUG INSPECTION [MZR 2.5] .) Is spark plug wet, covered with carbon or grayish white?	Yes	Spark plug is wet or covered with carbon: Inspect for fuel leakage from fuel injector. Spark plug is grayish white: Inspect the fuel injector for clogging. Repair or replace the malfunctioning part according to the inspection results.
10		No	Install the spark plugs on original cylinders. Go to the next step.
11	INSPECT DEFORMED IN EXHAUST SYSTEM Visually inspect the exhaust system part. Is there any deformed exhaust system part?	Yes	Repair or replace the malfunctioning part according to the inspection results.
11		No	Go to the next step.
12	INSPECT FUEL LINE PRESSURE Inspect the fuel line pressure. (See FUEL LINE PRESSURE INSPECTION [MZR 2.5] .) Is the fuel line pressure correct?	Yes	Go to the next step.
12		No	Zero or low: Inspect the following: Fuel pump relay Fuel pump circuit Fuel line for clogging If there is no malfunction, replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [MZR 2.5] .) High: Replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [MZR 2.5] .)
13	INSPECT FUEL SYSTEM FOR FUEL LEAKAGE Visually inspect for fuel leakage at the fuel injector O-ring and fuel line. Service if necessary. Is the fuel line pressure held after ignition is off? (See FUEL LINE PRESSURE INSPECTION [MZR 2.5] .)	Yes	Go to the next step.
13		No	Inspect the fuel injector. (See FUEL INJECTOR INSPECTION [MZR 2.5] .) If the fuel injector is normal, replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [MZR 2.5] .)
14	DETERMINE IF MALFUNCTION CAUSE IS A/C SYSTEM OR OTHER NOTE: The following test is for stall concerns with the A/C on. If other symptoms exist, go to the next step. Connect the pressure gauges to the A/C low side and high side pressure lines. Turn the A/C on and measure the low side and high side pressures. Are the pressures within the specifications? (See REFRIGERANT PRESSURE CHECK .)	Yes	Go to the next step.
14		No	If the A/C is always on: Go to the symptom troubleshooting "NO.24 A/C IS ALWAYS ON OR A/C COMPRESSOR RUNS CONTINUOUSLY". (See NO.24 A/C IS ALWAYS ON OR A/C COMPRESSOR RUNS CONTINUOUSLY [MZR 2.5] .) For other symptoms: Inspect the following: Refrigerant charging amount Cooling fan operation Repair or replace the malfunctioning part according to the inspection results.
15	DETERMINE IF MALFUNCTION CAUSE IS EVAP CONTROL SYSTEM OR OTHER Disconnect the vacuum hose between purge solenoid valve and intake manifold from the purge solenoid valve side. Plug the open end of the vacuum hose. Start the engine. Is the engine stall now eliminated?	Yes	Inspect the following: If the purge solenoid valve is stuck open. EVAP control system Repair or replace the malfunctioning part according to the inspection results.
15		No	Go to the next step.
16	INSPECT INTAKE AIR SYSTEM FOR AIR LEAKAGE Is air leakage felt or heard at the intake air system components while racing the engine to higher speed?	Yes	Repair or replace the malfunctioning part according to the inspection results.
16		No	Go to the next step.
17	INSPECT EGR VALVE FOR STUCK Inspect the engine condition while tapping the EGR valve housing. Does the engine condition improve?	Yes	Replace the EGR valve. (See EGR VALVE REMOVAL/INSTALLATION [MZR 2.5] .)
17		No	Go to the next step.
18	INSPECT VARIABLE VALVE TIMING CONTROL SYSTEM OPERATION Inspect the variable valve timing control system operation. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZR 2.5] .) Does the variable valve timing control system operate properly?	Yes	Go to the next step.
18		No	Repair or replace the malfunctioning part according to the inspection results.
19	INSPECT ENGINE COMPRESSION Is the engine compression correct? (See COMPRESSION INSPECTION [MZR 2.5] .)	Yes	Go to the next step.
19		No	Inspect for cause. Repair or replace the malfunctioning part according to the inspection results.
20	INSPECT IF MALFUNCTION CAUSE IS PCV VALVE OR VALVE TIMING Inspect the PCV valve. (See POSITIVE CRANKCASE VENTILATION (PCV) VALVE INSPECTION [MZR 2.5] .) Is the PCV valve normal?	Yes	Inspect the valve timing. Repair or replace the malfunctioning part according to the inspection results.
20		No	Replace the PCV valve and the oil separator as a single unit, then go to the next step. (See POSITIVE CRANKCASE VENTILATION (PCV) VALVE REMOVAL/INSTALLATION [MZR 2.5] .)
21	Verify test results. If normal, return to diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [MZR 2.5] .) 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, reprogram the PCM if a later calibration is available. Retest.

NOTE
The following test is for stall concerns with the A/C on. If other symptoms exist, go to the next step. Connect the pressure gauges to the A/C low side and high side pressure lines. Turn the A/C on and measure the low side and high side pressures. Are the pressures within the specifications? (See REFRIGERANT PRESSURE CHECK .)

STEP	INSPECTION	RESULTS	ACTION
1	INSPECT RELATED PART CONDITION Verify the following: Vacuum connection External fuel shut off or accessory (such as kill switch, alarm) Fuel quality: proper octane, contamination, winter/summer blend No air leakage from intake air system Intake air system restriction (such as air cleaner element, fresh air duct) Proper sealing of intake manifold and components attached to intake manifold: EGR valve Ignition wiring Electrical connections Fuses Smooth operation of throttle valve Are all items normal?	Yes	Go to the next step.
1		No	Repair or replace the malfunctioning part according to the inspection results. Repeat Step 1.
2	INSPECT APP SENSOR SIGNAL Access the PCM PIDs APP1 and APP2 using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZR 2.5] .) Crank the engine with the accelerator pedal released. Are the APP1 and APP2 PIDs indicating that the accelerator pedal is in the released position?	Yes	Go to the next step.
2		No	Inspect the following: APP sensor (See ACCELERATOR PEDAL POSITION (APP) SENSOR INSPECTION [MZR 2.5] .) Wiring harness and connector for the following: APP sensor terminal A-PCM terminal 1W APP sensor terminal B-PCM terminal 1AP APP sensor terminal C-PCM terminal 1AV APP sensor terminal D-PCM terminal 1AS APP sensor terminal E-PCM terminal 1AO APP sensor terminal F-PCM terminal 1AL Repair or replace the malfunctioning part according to the inspection results.
3	INSPECT TP SENSOR SIGNAL Access the PCM PID TP REL using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZR 2.5] .) Crank the engine with the accelerator pedal released. Is the TP REL PID indicating that the accelerator pedal is in the released position?	Yes	Go to the next step.
3		No	Inspect the following: TP sensor (See THROTTLE POSITION (TP) SENSOR INSPECTION [MZR 2.5] .) Wiring harness and connector for the following: TP sensor terminal A-PCM terminal 2AK TP sensor terminal B-PCM terminal 2AO TP sensor terminal C-PCM terminal 2AL TP sensor terminal D-PCM terminal 2AP Repair or replace the malfunctioning part according to the inspection results.
4	VERIFY PRESENT MALFUNCTION DTC Retrieve any continuous memory and KOEO DTCs using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZR 2.5] .) (See KOEO/KOER SELF TEST [MZR 2.5] .) Are there any DTCs displayed?	Yes	DTC is displayed: Go to the appropriate DTC inspection. (See DTC TABLE [MZR 2.5] .) Communication error message is displayed: Inspect the following: Open circuit in the wiring harness between main relay terminal B and PCM terminal 1Q Open circuit in the wiring harness between main relay terminal D and PCM terminal 1A, 1B Main relay is stuck open. Open or short circuit in the wiring harness between DLC-2 and PCM terminals 1AM or 1AI Open or poor ground circuit (PCM terminal 1E,1F,1G, 1BE, or 1BF) Poor connection of vehicle body ground Repair or replace the malfunctioning part according to the inspection results.
4		No	Go to the next step.
5	DETERMINE IF MALFUNCTION CAUSE IS DRIVE-BY-WIRE CONTROL SYSTEM OR OTHER Attempt to start the engine at part throttle. Does the engine run smoothly at part throttle.	Yes	Inspect the drive-by-wire control system operation. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZR 2.5] .) Repair or replace the malfunctioning part according to the inspection results.
5		No	Go to the next step.
6	DETERMINE IF MALFUNCTION CAUSE IS CKP SENSOR WIRING HARNESS OR OTHER Access the PCM PID RPM using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZR 2.5] .) Is the RPM PID indicating the engine speed during engine cranking?	Yes	Go to the next step.
6		No	Inspect the following: Open or short circuit in CKP sensor Open or short circuit between CKP sensor terminal A and ground Open or short circuit between CKP sensor terminal B and PCM terminal 2W Open or short circuit between CKP sensor terminal C and PCM terminal 2AQ Repair or replace the malfunctioning part according to the inspection results. If the CKP sensor and wiring harness are normal, go to the next step.
7	VISUALLY INSPECT CKP SENSOR AND PULSE WHEEL Visually inspect the CKP sensor and teeth of the crankshaft pulley. Are the CKP sensor and teeth of the crankshaft pulley normal?	Yes	Go to the next step.
7		No	Repair or replace the malfunctioning part according to the inspection results.
8	INSPECT IGNITION SYSTEM RELATED WIRING HARNESS Inspect the ignition coil related wiring harness condition (intermittent open or short circuit) for all cylinders. Are the wiring harness conditions normal?	Yes	Go to the next step.
8		No	Repair or replace suspected wiring harness and connector.
9	INSPECT IGNITION SYSTEM OPERATION Perform the Spark Test. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZR 2.5] .) Is a strong blue spark visible at each cylinder?	Yes	Go to the next step.
9		No	Repair or replace the malfunctioning part according to the inspection results.
10	VERIFY SPARK PLUG CONDITION Verify the spark plug conditions when the spark plug removed in Step 9. (See SPARK PLUG INSPECTION [MZR 2.5] .) Is spark plug wet, covered with carbon or grayish white?	Yes	Spark plug is wet or covered with carbon: Inspect for fuel leakage from fuel injector. Spark plug is grayish white: Inspect the fuel injector for clogging. Repair or replace the malfunctioning part according to the inspection results.
10		No	Install the spark plugs on original cylinders. Go to the next step.
11	INSPECT DEFORMED IN EXHAUST SYSTEM Visually inspect the exhaust system part. Is there any deformed exhaust system part?	Yes	Repair or replace the malfunctioning part according to the inspection results.
11		No	Go to the next step.
12	INSPECT FUEL LINE PRESSURE Inspect the fuel line pressure. (See FUEL LINE PRESSURE INSPECTION [MZR 2.5] .) Is the fuel line pressure correct?	Yes	Go to the next step.
12		No	Zero or low: Inspect the following: Fuel pump relay Fuel pump circuit Fuel line for clogging If there is no malfunction, replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [MZR 2.5] .) High: Replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [MZR 2.5] .)
13	INSPECT FUEL SYSTEM FOR FUEL LEAKAGE Visually inspect for fuel leakage at the fuel injector O-ring and fuel line. Service if necessary. Is the fuel line pressure held after ignition is off? (See FUEL LINE PRESSURE INSPECTION [MZR 2.5] .)	Yes	Go to the next step.
13		No	Inspect the fuel injector. (See FUEL INJECTOR INSPECTION [MZR 2.5] .) If the fuel injector is normal, replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [MZR 2.5] .)
14	DETERMINE IF MALFUNCTION CAUSE IS EVAP CONTROL SYSTEM OR OTHER Disconnect the vacuum hose between purge solenoid valve and intake manifold from the purge solenoid valve side. Plug the open end of the vacuum hose. Start the engine. Is the engine stall now eliminated?	Yes	Inspect the following: If the purge solenoid valve is stuck open. EVAP control system Repair or replace the malfunctioning part according to the inspection results.
14		No	Go to the next step.
15	INSPECT INTAKE AIR SYSTEM FOR AIR LEAKAGE Is air leakage felt or heard at the intake air system components while racing the engine to higher speed?	Yes	Repair or replace the malfunctioning part according to the inspection results.
15		No	Go to the next step.
16	INSPECT EGR VALVE FOR STUCK Inspect the engine condition while tapping the EGR valve housing. Does the engine condition improve?	Yes	Replace the EGR valve. (See EGR VALVE REMOVAL/INSTALLATION [MZR 2.5] .)
16		No	Go to the next step.
17	INSPECT VARIABLE VALVE TIMING CONTROL SYSTEM OPERATION Inspect the variable valve timing control system operation. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZR 2.5] .) Does the variable valve timing control system operate properly?	Yes	Go to the next step.
17		No	Repair or replace the malfunctioning part according to the inspection results.
18	INSPECT IF MALFUNCTION CAUSE IS LOW ENGINE COMPRESSION OR VALVE TIMING Is the engine compression correct? (See COMPRESSION INSPECTION [MZR 2.5] .)	Yes	Inspect the valve timing. Repair or replace the malfunctioning part according to the inspection results.
18		No	Inspect for cause. Repair or replace the malfunctioning part according to the inspection results.
19	Verify test results. If normal, return to diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [MZR 2.5] .) 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, reprogram the PCM if a later calibration is available. Retest.

STEP	INSPECTION	RESULTS	ACTION
1	VERIFY PCM DTC Retrieve any DTCs using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZR 2.5] .) Are there any DTCs displayed?	Yes	Go to the appropriate DTC inspection. (See DTC TABLE [MZR 2.5] .)
1		No	Go to the next step.
2	INSPECT POWER STEERING OPERATION SIGNAL Access the PCM PID PSP using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZR 2.5] .) Do the PIDs indicate the correct values under trouble condition?	Yes	Go to the next step.
2		No	Inspect the PSP switch and the related harnesses. (See POWER STEERING PRESSURE (PSP) SWITCH INSPECTION [MZR 2.5] .) Repair or replace the malfunctioning part according to the inspection results. If the malfunction remains, perform the intermittent concern troubleshooting procedure. (See INTERMITTENT CONCERN TROUBLESHOOTING [MZR 2.5] .)
3	INSPECT ECT SENSOR SIGNAL Access and monitor the PCM PID ECT using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZR 2.5] .) Start the engine and warm it up to ECT PID is above 90 °C {194 °F} . Does the ECT PID increasing dull at the thermostat initial opening temperature? Thermostat initial opening temperature: 80-84 °C {176-183 °F}	Yes	Thermostat operation is normal. Go to the next step.
3		No	Inspect characteristic of the ECT sensor. (See ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION [MZR 2.5] .) If normal, replace the thermostat. (See THERMOSTAT REMOVAL/INSTALLATION [MZR 2.5] .)
4	VISUALLY INSPECT THROTTLE BODY Is the throttle body free of contamination?	Yes	Inspect for air leakage from the intake air system components while racing the engine to higher speed. Repair or replace the malfunctioning part according to the inspection results.
4		No	Clean or replace throttle body. (See INTAKE-AIR SYSTEM REMOVAL/INSTALLATION [MZR 2.5] .)
5	Verify test results. If normal, return to diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [MZR 2.5] .) 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, reprogram the PCM if a later calibration is available. Retest.

STEP	INSPECTION	RESULTS	ACTION
1	INSPECT IF MALFUNCTION CAUSE IS DRIVE-BY-WIRE CONTROL SYSTEM IDLE LEARNING NOT PERFORMED Warm up the engine. Idle the engine for 5 min. Does the symptom disappear?	Yes	Symptom troubleshooting is completed. (Cause of this symptom is that the idle learning for drive-by-wire control system is not completed.)
1		No	Go to the next step.
2	INSPECT RELATED PART CONDITION Verify the following: External fuel shut off or accessory (such as kill switch, alarm) Fuel quality (such as proper octane, contamination, winter/summer blend) No air leakage from intake air system Proper sealing of intake manifold and components attached to intake manifold: EGR valve Ignition wiring Electrical connections Fuses Smooth operation of throttle valve Air cleaner restriction Vacuum leakage from intake air system PCM ground circuit (1E, 1F, 1G, 1BE, or 1BF) Are all items normal?	Yes	Go to the next step.
2		No	Repair or replace the malfunctioning part according to the inspection results. Repeat Step 2.
3	VERIFY PCM DTC Retrieve any DTCs using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZR 2.5] .) Are there any DTCs displayed?	Yes	Go to the appropriate DTC inspection. (See DTC TABLE [MZR 2.5] .)
3		No	Go to the next step.
4	VERIFY IF MALFUNCTION CAUSE IS OVERHEATING Is the engine overheating?	Yes	Go to the symptom troubleshooting "NO.17 COOLING SYSTEM CONCERNS-OVERHEATING". (See NO.17 COOLING SYSTEM CONCERNS-OVERHEATING [MZR 2.5] .)
4		No	Go to the next step.
5	INSPECT MAF SENSOR SIGNAL CAUTION: While performing this step, always operate the vehicle in a safe and lawful manner. When the M-MDS is used to observe monitor system status while driving, be sure to have another technician with you, or record the data in the M-MDS using the PID/DATA MONITOR AND RECORD capturing function and inspect later. Access the PCM PID MAF using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZR 2.5] .) Drive the vehicle while monitoring the PID. Is the MAF PID within the specification?	Yes	Go to the next step.
5		No	Inspect for an open or short circuit in the MAF sensor and related wiring harness. Repair or replace the malfunctioning part according to the inspection results.
6	INSPECT POWER STEERING OPERATION SIGNAL Access the PCM PID PSP using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZR 2.5] .) Do the PIDs indicate the correct values under trouble condition?	Yes	Go to the next step.
6		No	Inspect the PSP switch and the related harnesses. (See POWER STEERING PRESSURE (PSP) SWITCH INSPECTION [MZR 2.5] .) Repair or replace the malfunctioning part according to the inspection results. If the malfunction remains, perform the intermittent concern troubleshooting procedure. (See INTERMITTENT CONCERN TROUBLESHOOTING [MZR 2.5] .)
7	DETERMINE IF MALFUNCTION CAUSE IS A/C SYSTEM OR OTHER NOTE: The following test is for stall concerns with the A/C on. If other symptoms exist, go to the next step. Connect the pressure gauges to the A/C low side and high side pressure lines. Turn the A/C on and measure the low side and high side pressures. Are the pressures within the specifications? (See REFRIGERANT PRESSURE CHECK .)	Yes	Go to the next step.
7		No	If the A/C is always on: Go to the symptom troubleshooting "NO.24 A/C IS ALWAYS ON OR A/C COMPRESSOR RUNS CONTINUOUSLY". (See NO.24 A/C IS ALWAYS ON OR A/C COMPRESSOR RUNS CONTINUOUSLY [MZR 2.5] .) For other symptoms: Inspect the following: Refrigerant charging amount Cooling fan operation Repair or replace the malfunctioning part according to the inspection results.
8	VISUALLY INSPECT CKP SENSOR AND PULSE WHEEL Visually inspect the CKP sensor and teeth of the crankshaft pulley. Are the CKP sensor and teeth of the crankshaft pulley normal?	Yes	Go to the next step.
8		No	Repair or replace the malfunctioning part according to the inspection results.
9	INSPECT IGNITION SYSTEM RELATED WIRING HARNESS Inspect the ignition coil related wiring harness condition (intermittent open or short circuit) for all cylinders. Are the wiring harness conditions normal?	Yes	Go to the next step.
9		No	Repair or replace suspected wiring harness and connector.
10	INSPECT IGNITION SYSTEM OPERATION Perform the Spark Test. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZR 2.5] .) Is a strong blue spark visible at each cylinder?	Yes	Go to the next step.
10		No	Repair or replace the malfunctioning part according to the inspection results.
11	VERIFY SPARK PLUG CONDITION Verify the spark plug conditions when the spark plug removed in Step 10. (See SPARK PLUG INSPECTION [MZR 2.5] .) Is spark plug wet, covered with carbon or grayish white?	Yes	Spark plug is wet or covered with carbon: Inspect for fuel leakage from fuel injector. Spark plug is grayish white: Inspect the fuel injector for clogging. Repair or replace the malfunctioning part according to the inspection results.
11		No	Install the spark plugs on original cylinders. Go to the next step.
12	INSPECT DRIVE-BY-WIRE CONTROL SYSTEM OPERATION Perform the drive-by-wire control system operation inspection. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZR 2.5] .) Does the drive-by-wire control system function properly?	Yes	Go to the next step.
12		No	Repair or replace the malfunctioning part according to the inspection results.
13	INSPECT FUEL LINE PRESSURE Inspect the fuel line pressure. (See FUEL LINE PRESSURE INSPECTION [MZR 2.5] .) Is the fuel line pressure correct?	Yes	Go to the next step.
13		No	Zero or low: Inspect the following: Fuel pump relay Fuel pump circuit Fuel line for clogging If there is no malfunction, replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [MZR 2.5] .) High: Replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [MZR 2.5] .)
14	INSPECT FUEL SYSTEM FOR FUEL LEAKAGE Visually inspect for fuel leakage at the fuel injector O-ring and fuel line. Service if necessary. Is the fuel line pressure held after ignition is off? (See FUEL LINE PRESSURE INSPECTION [MZR 2.5] .)	Yes	Go to the next step.
14		No	Inspect the fuel injector. (See FUEL INJECTOR INSPECTION [MZR 2.5] .) If the fuel injector is normal, replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [MZR 2.5] .)
15	INSPECT LONG TERM FUEL TRIM Start the engine and idle it. Access the PCM PID LONG FT1 using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZR 2.5] .) Measure the LONG FT1 PID at idle. Is the PID value between -14 % and +14 % ?	Yes	Go to the next step.
15		No	Less than specification (too rich): Inspect the EVAP control system. Repair or replace the malfunctioning part according to the inspection results. Greater than specification (too lean): Inspect for air leakage at the intake air system components. Repair or replace the malfunctioning part according to the inspection results. If the system is normal, go to the next step.
16	DETERMINE IF MALFUNCTION CAUSE IS EVAP CONTROL SYSTEM OR OTHER Disconnect the vacuum hose between purge solenoid valve and intake manifold from the purge solenoid valve side. Plug the open end of the vacuum hose. Start the engine. Does the engine condition improve?	Yes	Inspect the following: If the purge solenoid valve is stuck open. EVAP control system Repair or replace the malfunctioning part according to the inspection results.
16		No	Go to the next step.
17	INSPECT DEFORMED IN EXHAUST SYSTEM Visually inspect the exhaust system part. Is there any deformed exhaust system part?	Yes	Repair or replace the malfunctioning part according to the inspection results.
17		No	Go to the next step.
18	VISUALLY INSPECT CMP SENSOR AND PULSE WHEEL Visually inspect the CMP sensor and teeth of the camshaft. (See CAMSHAFT POSITION (CMP) SENSOR INSPECTION [MZR 2.5] .) Are the CMP sensor and teeth of the camshaft normal?	Yes	Go to the next step.
18		No	Repair or replace the malfunctioning part according to the inspection results.
19	INSPECT EGR VALVE FOR STUCK Inspect the engine condition while tapping the EGR valve housing. Does the engine condition improve?	Yes	Replace the EGR valve. (See EGR VALVE REMOVAL/INSTALLATION [MZR 2.5] .)
19		No	Go to the next step.
20	INSPECT VARIABLE VALVE TIMING CONTROL SYSTEM OPERATION Inspect the variable valve timing control system operation. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZR 2.5] .) Does the variable valve timing control system operate properly?	Yes	Go to the next step.
20		No	Repair or replace the malfunctioning part according to the inspection results.
21	INSPECT ENGINE COMPRESSION Is the engine compression correct? (See COMPRESSION INSPECTION [MZR 2.5] .)	Yes	Go to the next step.
21		No	Inspect for cause. Repair or replace the malfunctioning part according to the inspection results.
22	INSPECT IF MALFUNCTION CAUSE IS PCV VALVE OR VALVE TIMING Inspect the PCV valve. (See POSITIVE CRANKCASE VENTILATION (PCV) VALVE INSPECTION [MZR 2.5] .) Is the PCV valve normal?	Yes	Inspect the valve timing. Repair or replace the malfunctioning part according to the inspection results.
22		No	Replace the PCV valve and the oil separator as a single unit, then go to the next step. (See POSITIVE CRANKCASE VENTILATION (PCV) VALVE REMOVAL/INSTALLATION [MZR 2.5] .)
23	Verify test results. If normal, return to diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [MZR 2.5] .) 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, reprogram the PCM if a later calibration is available. Retest.

CAUTION
While performing this step, always operate the vehicle in a safe and lawful manner. When the M-MDS is used to observe monitor system status while driving, be sure to have another technician with you, or record the data in the M-MDS using the PID/DATA MONITOR AND RECORD capturing function and inspect later. Access the PCM PID MAF using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZR 2.5] .) Drive the vehicle while monitoring the PID. Is the MAF PID within the specification?

CAUTION

While performing this step, always operate the vehicle in a safe and lawful manner. When the M-MDS is used to observe monitor system status while driving, be sure to have another technician with you, or record the data in the M-MDS using the PID/DATA MONITOR AND RECORD capturing function and inspect later. Access the PCM PID MAF using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZR 2.5] .) Drive the vehicle while monitoring the PID. Is the MAF PID within the specification?

NOTE
The following test is for stall concerns with the A/C on. If other symptoms exist, go to the next step. Connect the pressure gauges to the A/C low side and high side pressure lines. Turn the A/C on and measure the low side and high side pressures. Are the pressures within the specifications? (See REFRIGERANT PRESSURE CHECK .)

STEP	INSPECTION	RESULTS	ACTION
1	INSPECT COOLING SYSTEM FOR MALFUNCTION Access the PCM PID ECT using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZR 2.5] .) Start and warm up the engine to normal operating temperature. Is the ECT PID between 82-112 °C {180-233 °F} ?	Yes	Go to the next step.
1		No	ECT PID is higher than 112 °C {233 °F} : Go to the symptom troubleshooting "NO.17 COOLING SYSTEM CONCERNS-OVERHEATING". (See NO.17 COOLING SYSTEM CONCERNS-OVERHEATING [MZR 2.5] .) ECT PID is less than 82 °C {180 °F} : Go to the symptom troubleshooting "NO.18 COOLING SYSTEM CONCERNS-RUNS COLD". (See NO.18 COOLING SYSTEM CONCERNS-RUNS COLD [MZR 2.5] .)
2	VERIFY PCM DTC Retrieve any DTCs using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZR 2.5] .) Are there any DTCs displayed?	Yes	Go to the appropriate DTC inspection. (See DTC TABLE [MZR 2.5] .)
2		No	Go to the next step.
3	VERIFY CURRENT INPUT SIGNAL STATUS Access and monitor the following PCM PIDs using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZR 2.5] .) AC_REQ COLP CPP (MTX) CPP/PNP (MTX) PSP TR (ATX) Are all PID values normal? (See PCM INSPECTION [MZR 2.5] .)	Yes	Go to the next step.
3		No	AC_REQ PID is not specified: Inspect the following: A/C switch, evaporator temperature sensor and fan switch (See EVAPORATOR TEMPERATURE SENSOR INSPECTION [FULL-AUTO AIR CONDITIONER] .) (See EVAPORATOR TEMPERATURE SENSOR INSPECTION [MANUAL AIR CONDITIONER] .) Communication between climate control unit and instrument cluster (Full-auto air conditioner) Communication between instrument cluster and PCM Short to ground in wiring harness between instrument cluster terminal 1A and climate control unit terminal 1L (Manual air conditioner) COLP PID is not specified: Inspect the refrigerant pressure sensor. (See REFRIGERANT PRESSURE SENSOR INSPECTION [FULL-AUTO AIR CONDITIONER] .) (See REFRIGERANT PRESSURE SENSOR INSPECTION [MANUAL AIR CONDITIONER] .) CPP PID is not specified: Inspect the CPP switch (MTX). (See CLUTCH PEDAL POSITION (CPP) SWITCH INSPECTION [MZR 2.5] .) CPP/PNP PID: Inspect the neutral switch (MTX). (See NEUTRAL SWITCH INSPECTION [MZR 2.5] .) PSP PID: Inspect PSP switch (See POWER STEERING PRESSURE (PSP) SWITCH INSPECTION [MZR 2.5] .) TR PID: Inspect the TR switch (ATX). (See TRANSAXLE RANGE (TR) SWITCH INSPECTION [FS5A-EL] .) Repair or replace the malfunctioning part according to the inspection results.
4	INSPECT INTAKE AIR SYSTEM FOR AIR LEAKAGE Is there air leakage felt or heard at the intake air system components while racing the engine to higher speed?	Yes	Repair or replace the malfunctioning part according to the inspection results.
4		No	Inspect the following: Drive-by-wire control system operation (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZR 2.5] .) APP sensor (See ACCELERATOR PEDAL POSITION (APP) SENSOR INSPECTION [MZR 2.5] .) Repair or replace the malfunctioning part according to the inspection results.
5	Verify test results. If normal, return to diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [MZR 2.5] .) 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, reprogram the PCM if a later calibration is available. Retest.

STEP	INSPECTION	RESULTS	ACTION
1	VERIFY IF MALFUNCTION INCLUDES ROUGH IDLING Does the engine idle roughly?	Yes	Go to the symptom troubleshooting "NO.8 ENGINE RUNS ROUGH/ROLLING IDLE". (See NO.8 ENGINE RUNS ROUGH/ROLLING IDLE [MZR 2.5] .)
1		No	Go to the next step.
2	DETERMINE IF MALFUNCTION CAUSE IS A/C SYSTEM OR OTHER Turn off the A/C switch and fan switch. Does the magnetic clutch engage?	Yes	Go to the symptom troubleshooting "NO.24 A/C IS ALWAYS ON OR A/C COMPRESSOR RUNS CONTINUOUSLY." (See NO.24 A/C IS ALWAYS ON OR A/C COMPRESSOR RUNS CONTINUOUSLY [MZR 2.5] .)
2		No	Go to the next step.
3	INSPECT RELATED PART CONDITION Verify the following: Proper routing of and no damage to the vacuum lines No air leakage from the intake air system Are all items normal?	Yes	Go to the next step.
3		No	Repair or replace the malfunctioning part according to the inspection results. Repeat Step 3.
4	VERIFY PCM DTC Retrieve any DTCs using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZR 2.5] .) Are there any DTCs displayed?	Yes	Go to the appropriate DTC inspection. (See DTC TABLE [MZR 2.5] .)
4		No	Go to the next step.
5	INSPECT DRIVE-BY-WIRE CONTROL SYSTEM OPERATION Perform the drive-by-wire control system operation inspection. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZR 2.5] .) Does the drive-by-wire control system function properly?	Yes	Go to the next step.
5		No	Repair or replace the malfunctioning part according to the inspection results.
6	DETERMINE IF MALFUNCTION CAUSE IS EVAP CONTROL SYSTEM OR OTHER CAUTION: While performing this step, always operate the vehicle in a safe and lawful manner. Disconnect the vacuum hose between purge solenoid valve and intake manifold from the purge solenoid valve side. Plug the open end of the vacuum hose. Drive the vehicle. Does the engine condition improve?	Yes	Inspect the EVAP control system. Repair or replace the malfunctioning part according to the inspection results.
6		No	Go to the next step.
7	VERIFY CURRENT INPUT SIGNAL STATUS CAUTION: While performing this step, always operate the vehicle in a safe and lawful manner. When the M-MDS is used to observe monitor system status while driving, be sure to have another technician with you, or record the data in the M-MDS using the PID/DATA MONITOR AND RECORD capturing function and inspect later. Access the following PCM PIDs using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZR 2.5] .) APP1 APP2 TP REL MAF VSS Do the PIDs indicate correct values under the trouble condition? (See PCM INSPECTION [MZR 2.5] .)	Yes	Go to the next step.
7		No	APP1, APP2 PIDs are not specified: Inspect if the output signal APP sensor changes smoothly. (See ACCELERATOR PEDAL POSITION (APP) SENSOR INSPECTION [MZR 2.5] .) TP REL PID is not specified: Inspect if the output signal TP sensor changes smoothly. (See THROTTLE POSITION (TP) SENSOR INSPECTION [MZR 2.5] .) MAF PID is not specified: Inspect for an intermittent open circuit of MAF sensor and the related wiring harness. (See MASS AIR FLOW (MAF) SENSOR INSPECTION [MZR 2.5] .) VSS PID is not specified: Inspect for an intermittent open circuit in the VSS and related wiring harness. (See VEHICLE SPEED SENSOR (VSS) INSPECTION [FS5A-EL] .) Repair or replace the malfunctioning part according to the inspection result.
8	VERIFY CURRENT INPUT SIGNAL STATUS Access and monitor the following PCM PIDs using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZR 2.5] .) AC_REQ COLP CPP (MTX) CPP/PNP (MTX) TR (ATX) Are all PID values normal? (See PCM INSPECTION [MZR 2.5] .)	Yes	MTX: Go to the next step. ATX: Inspect the TCC operation. (See NO.25 ENGINE STALLS WHEN DRIVING AT SLOW SPEEDS OR STOPPING [FS5A-EL] .)
8		No	AC_REQ PID is not specified: Inspect the following: A/C switch, evaporator temperature sensor and fan switch (See EVAPORATOR TEMPERATURE SENSOR INSPECTION [FULL-AUTO AIR CONDITIONER] .) (See EVAPORATOR TEMPERATURE SENSOR INSPECTION [MANUAL AIR CONDITIONER] .) Communication between climate control unit and instrument cluster (Full-auto air conditioner) Communication between instrument cluster and PCM Short to ground in wiring harness between instrument cluster terminal 1A and climate control unit terminal 1L (Manual air conditioner) COLP PID is not specified: Inspect the refrigerant pressure sensor. (See REFRIGERANT PRESSURE SENSOR INSPECTION [FULL-AUTO AIR CONDITIONER] .) (See REFRIGERANT PRESSURE SENSOR INSPECTION [MANUAL AIR CONDITIONER] .) CPP PID is not specified: Inspect the CPP switch (MTX). (See CLUTCH PEDAL POSITION (CPP) SWITCH INSPECTION [MZR 2.5] .) CPP/PNP PID: Inspect the neutral switch (MTX). (See NEUTRAL SWITCH INSPECTION [MZR 2.5] .) TR PID: Inspect the TR switch (ATX). (See TRANSAXLE RANGE (TR) SWITCH INSPECTION [FS5A-EL] .) Repair or replace the malfunctioning part according to the inspection results.
9	Verify test results. If normal, return to diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [MZR 2.5] .) 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, reprogram the PCM if a later calibration is available. Retest.

CAUTION
While performing this step, always operate the vehicle in a safe and lawful manner. Disconnect the vacuum hose between purge solenoid valve and intake manifold from the purge solenoid valve side. Plug the open end of the vacuum hose. Drive the vehicle. Does the engine condition improve?

CAUTION
While performing this step, always operate the vehicle in a safe and lawful manner. When the M-MDS is used to observe monitor system status while driving, be sure to have another technician with you, or record the data in the M-MDS using the PID/DATA MONITOR AND RECORD capturing function and inspect later. Access the following PCM PIDs using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZR 2.5] .) APP1 APP2 TP REL MAF VSS Do the PIDs indicate correct values under the trouble condition? (See PCM INSPECTION [MZR 2.5] .)

CAUTION

While performing this step, always operate the vehicle in a safe and lawful manner. When the M-MDS is used to observe monitor system status while driving, be sure to have another technician with you, or record the data in the M-MDS using the PID/DATA MONITOR AND RECORD capturing function and inspect later. Access the following PCM PIDs using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZR 2.5] .) APP1 APP2 TP REL MAF VSS Do the PIDs indicate correct values under the trouble condition? (See PCM INSPECTION [MZR 2.5] .)

STEP	INSPECTION	RESULTS	ACTION
1	CONFIRM DRIVE-BY-WIRE CONTROL SYSTEM OPERATES WITH BRAKE OVERRIDE SYSTEM Retrieve any continuous memory DTCs. (See ON-BOARD DIAGNOSTIC TEST [MZR 2.5] .) Is the DTC P2299:00 present?	Yes	Go to the applicable DTC inspection. (Drive-by-wire control system operates with brake override system.) (See DTC P2299:00 [MZR 2.5] .)
1		No	Go to the next step.
2	INSPECT RELATED PART CONDITION Verify the following: Vacuum connection Air cleaner element No air leakage from intake air system No restriction of the intake air system Proper sealing of intake manifold and components attached to intake manifold: such as EGR valve Ignition wiring Fuel quality (such as proper octane, contamination, winter/summer blend) Electrical connections Smooth operation of the throttle valve Are all the items normal?	Yes	Go to the next step.
2		No	Repair or replace the malfunctioning part according to the inspection results. Repeat Step 2.
3	VERIFY PCM DTC Retrieve any DTCs using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZR 2.5] .) Are there any DTCs displayed?	Yes	Go to the appropriate DTC inspection. (See DTC TABLE [MZR 2.5] .)
3		No	Go to the next step.
4	VERIFY IF MALFUNCTION CAUSE IS OVERHEATING Is the engine overheating?	Yes	Go to the symptom troubleshooting "NO.17 COOLING SYSTEM CONCERNS-OVERHEATING". (See NO.17 COOLING SYSTEM CONCERNS-OVERHEATING [MZR 2.5] .)
4		No	Go to the next step.
5	INSPECT THROTTLE BODY FOR CLOGGING Visually inspect the throttle valve. (See INTAKE-AIR SYSTEM REMOVAL/INSTALLATION [MZR 2.5] .) Are any foreign material adhere to around throttle valve?	Yes	Clean the throttle valve.
5		No	Go to the next step.
6	VERIFY CURRENT INPUT SIGNAL STATUS CAUTION: While performing this step, always operate the vehicle in a safe and lawful manner. When the M-MDS is used to observe monitor system status while driving, be sure to have another technician with you, or record the data in the M-MDS using the PID/DATA MONITOR AND RECORD capturing function and inspect later. Access the following PCM PIDs using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZR 2.5] .) APP1 APP2 RPM VPWR MAF MAP BARO TP REL VSS Do the PIDs indicate correct values under the trouble condition? (See PCM INSPECTION [MZR 2.5] .)	Yes	Go to the next step.
6		No	APP1, APP2 PIDs are not specified: Inspect if the output signal APP sensor changes smoothly. (See ACCELERATOR PEDAL POSITION (APP) SENSOR INSPECTION [MZR 2.5] .) TP REL PID is not specified: Inspect if the output signal TP sensor changes smoothly. (See THROTTLE POSITION (TP) SENSOR INSPECTION [MZR 2.5] .) RPM PID is not specified: Inspect the CKP sensor and the related wiring harness for vibration or intermittent open/short circuit or both. (See CRANKSHAFT POSITION (CKP) SENSOR INSPECTION [MZR 2.5] .) MAF PID is not specified: Inspect for an intermittent open circuit of MAF sensor and the related wiring harness. (See MASS AIR FLOW (MAF) SENSOR INSPECTION [MZR 2.5] .) MAP PID is not specified: Inspect the MAP sensor and related wiring harness for vibration or an intermittent open/short circuit. (See MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR INSPECTION [MZR 2.5] .) BARO PID is not specified: Replace the PCM. (See PCM REMOVAL/INSTALLATION [MZR 2.5] .) VPWR PID is not specified: Inspect for an intermittent open circuit. VSS PID is not specified: Inspect for an intermittent open circuit in the VSS and related wiring harness. (See VEHICLE SPEED SENSOR (VSS) INSPECTION [FS5A-EL] .) Repair or replace the malfunctioning part according to the inspection result.
7	VISUALLY INSPECT CKP SENSOR AND PULSE WHEEL Visually inspect the CKP sensor and teeth of the crankshaft pulley. (See CRANKSHAFT POSITION (CKP) SENSOR INSPECTION [MZR 2.5] .) Are the CKP sensor and teeth of the crankshaft pulley normal?	Yes	Go to the next step.
7		No	Repair or replace the malfunctioning part according to the inspection result.
8	VERIFY SPARK PLUG CONDITION Verify the spark plug conditions when the spark plug removed in Step 8. (See SPARK PLUG INSPECTION [MZR 2.5] .) Is spark plug wet, covered with carbon or grayish white?	Yes	Spark plug is wet or covered with carbon: Inspect for fuel leakage from fuel injector. Spark plug is grayish white: Inspect the fuel injector for clogging. Repair or replace the malfunctioning part according to the inspection results.
8		No	Install the spark plugs on original cylinders. Go to the next step.
9	INSPECT DRIVE-BY-WIRE CONTROL SYSTEM OPERATION Perform the drive-by-wire control system operation inspection. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZR 2.5] .) Does the drive-by-wire control system function properly?	Yes	Go to the next step.
9		No	Repair or replace the malfunctioning part according to the inspection results.
10	INSPECT DEFORMED IN EXHAUST SYSTEM Visually inspect the exhaust system part. Is there any deformed exhaust system part?	Yes	Repair or replace the malfunctioning part according to the inspection results.
10		No	Go to the next step.
11	INSPECT FUEL LINE PRESSURE Inspect the fuel line pressure. (See FUEL LINE PRESSURE INSPECTION [MZR 2.5] .) Is the fuel line pressure correct?	Yes	Go to the next step.
11		No	Zero or low: Inspect the following: Fuel pump relay Fuel pump circuit Fuel line for clogging If there is no malfunction, replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [MZR 2.5] .) High: Replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [MZR 2.5] .)
12	INSPECT FUEL SYSTEM FOR FUEL LEAKAGE Visually inspect for fuel leakage at the fuel injector O-ring and fuel line. Service if necessary. Is the fuel line pressure held after ignition is off? (See FUEL LINE PRESSURE INSPECTION [MZR 2.5] .)	Yes	Go to the next step.
12		No	Inspect the fuel injector. (See FUEL INJECTOR INSPECTION [MZR 2.5] .) If the fuel injector is normal, replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [MZR 2.5] .)
13	DETERMINE IF MALFUNCTION CAUSE IS A/C SYSTEM OR OTHER NOTE: The following test is for stall concerns with the A/C on. If other symptoms exist, go to the next step. Connect the pressure gauges to the A/C low side and high side pressure lines. Turn the A/C on and measure the low side and high side pressures. Are the pressures within the specifications? (See REFRIGERANT PRESSURE CHECK .)	Yes	Go to the next step.
13		No	If the A/C is always on: Go to the symptom troubleshooting "NO.24 A/C IS ALWAYS ON OR A/C COMPRESSOR RUNS CONTINUOUSLY". (See NO.24 A/C IS ALWAYS ON OR A/C COMPRESSOR RUNS CONTINUOUSLY [MZR 2.5] .) For other symptoms: Inspect the following: Refrigerant charging amount Cooling fan operation Repair or replace the malfunctioning part according to the inspection results.
14	INSPECT CRUISE CONTROL SYSTEM NOTE: The following test should be performed for symptoms with the cruise control on. If other symptoms exist, go to the next step. Inspect the cruise control system operation. Is the cruise control system normal?	Yes	Go to the next step.
14		No	Repair or replace the malfunctioning part according to the inspection results.
15	INSPECT CURRENT A/F SENSOR SIGNAL Inspect the A/F sensor. (See AIR FUEL RATIO (A/F) SENSOR INSPECTION [MZR 2.5] .) Is the A/F sensor normal?	Yes	Go to Step 17.
15		No	Go to the next step.
16	DETERMINE IF MALFUNCTION CAUSE IS A/F SENSOR MALFUNCTION OR A/F SENSOR RELATED WIRING HARNESS MALFUNCTION NOTE: If the inspection in Step 16 is performed, the PCM detects a DTC and performs fail-safe control. After performing the inspection, clear DTCs using the M-MDS. Switch the ignition to off. Disconnect the A/F sensor connector. Verify the symptom. Does the symptom disappear?	Yes	Replace the A/F sensor. (See AIR FUEL RATIO (A/F) SENSOR REMOVAL/INSTALLATION [MZR 2.5] .)
16		No	Inspect the following: Exhaust gas leakage between exhaust manifold and A/F sensor Loose installation of A/F sensor Repair or replace the malfunctioning part according to the inspection results. If there is no malfunction, inspect the A/F sensor signal circuit. Repair or replace suspected wiring harness and connector.
17	DETERMINE IF MALFUNCTION CAUSE IS FUEL SHUT-OFF VALVE OR OTHER Inspect the evaporative purge hose between fuel tank and purge solenoid valve. Does the fuel flow into the evaporative purge hose?	Yes	Inspect the fuel shut-off valve. (See FUEL SHUT-OFF VALVE INSPECTION [MZR 2.5] .) Repair or replace the malfunctioning part according to the inspection results.
17		No	Go to the next step.
18	DETERMINE IF MALFUNCTION CAUSE IS EVAP CONTROL SYSTEM OR OTHER CAUTION: While performing this step, always operate the vehicle in a safe and lawful manner. Disconnect the vacuum hose between purge solenoid valve and intake manifold from the purge solenoid valve side. Plug the open end of the vacuum hose. Drive the vehicle. Does the engine condition improve?	Yes	Inspect the following: If the purge solenoid valve is stuck open. EVAP control system Repair or replace the malfunctioning part according to the inspection results.
18		No	Go to the next step.
19	VISUALLY INSPECT CMP SENSOR AND PULSE WHEEL Visually inspect the CMP sensor and teeth of the camshaft. (See CAMSHAFT POSITION (CMP) SENSOR INSPECTION [MZR 2.5] .) Are the CMP sensor and teeth of the camshaft normal?	Yes	Go to the next step.
19		No	Repair or replace the malfunctioning part according to the inspection results.
20	INSPECT VARIABLE VALVE TIMING CONTROL SYSTEM OPERATION Inspect the variable valve timing control system operation. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZR 2.5] .) Does the variable valve timing control system operate properly?	Yes	Go to the next step.
20		No	Repair or replace the malfunctioning part according to the inspection results.
21	INSPECT EGR VALVE OPERATION Perform the EGR control system inspection. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZR 2.5] .) Is the EGR control system normal?	Yes	Go to the next step.
21		No	Repair or replace the malfunctioning part according to the inspection results.
22	INSPECT ENGINE COMPRESSION Is the engine compression correct? (See COMPRESSION INSPECTION [MZR 2.5] .)	Yes	Go to the next step.
22		No	Inspect for cause. Repair or replace the malfunctioning part according to the inspection results.
23	INSPECT IF MALFUNCTION CAUSE IS PCV VALVE OR VALVE TIMING Inspect the PCV valve. (See POSITIVE CRANKCASE VENTILATION (PCV) VALVE INSPECTION [MZR 2.5] .) Is the PCV valve normal?	Yes	Inspect the following: Valve timing Internal transaxle part (ATX) EGR valve (mechanical stuck) Check valve (two-way) Repair or replace the malfunctioning part according to the inspection results.
23		No	Replace the PCV valve and the oil separator as a single unit, then go to the next step. (See POSITIVE CRANKCASE VENTILATION (PCV) VALVE REMOVAL/INSTALLATION [MZR 2.5] .)
24	Verify test results. If normal, return to diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [MZR 2.5] .) 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, reprogram the PCM if a later calibration is available. Retest.

CAUTION
While performing this step, always operate the vehicle in a safe and lawful manner. When the M-MDS is used to observe monitor system status while driving, be sure to have another technician with you, or record the data in the M-MDS using the PID/DATA MONITOR AND RECORD capturing function and inspect later. Access the following PCM PIDs using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZR 2.5] .) APP1 APP2 RPM VPWR MAF MAP BARO TP REL VSS Do the PIDs indicate correct values under the trouble condition? (See PCM INSPECTION [MZR 2.5] .)

CAUTION

While performing this step, always operate the vehicle in a safe and lawful manner. When the M-MDS is used to observe monitor system status while driving, be sure to have another technician with you, or record the data in the M-MDS using the PID/DATA MONITOR AND RECORD capturing function and inspect later. Access the following PCM PIDs using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZR 2.5] .) APP1 APP2 RPM VPWR MAF MAP BARO TP REL VSS Do the PIDs indicate correct values under the trouble condition? (See PCM INSPECTION [MZR 2.5] .)

NOTE
The following test is for stall concerns with the A/C on. If other symptoms exist, go to the next step. Connect the pressure gauges to the A/C low side and high side pressure lines. Turn the A/C on and measure the low side and high side pressures. Are the pressures within the specifications? (See REFRIGERANT PRESSURE CHECK .)

NOTE
The following test should be performed for symptoms with the cruise control on. If other symptoms exist, go to the next step. Inspect the cruise control system operation. Is the cruise control system normal?

NOTE
If the inspection in Step 16 is performed, the PCM detects a DTC and performs fail-safe control. After performing the inspection, clear DTCs using the M-MDS. Switch the ignition to off. Disconnect the A/F sensor connector. Verify the symptom. Does the symptom disappear?

CAUTION
While performing this step, always operate the vehicle in a safe and lawful manner. Disconnect the vacuum hose between purge solenoid valve and intake manifold from the purge solenoid valve side. Plug the open end of the vacuum hose. Drive the vehicle. Does the engine condition improve?

STEP	INSPECTION	RESULTS	ACTION
1	CONFIRM DRIVE-BY-WIRE CONTROL SYSTEM OPERATES WITH BRAKE OVERRIDE SYSTEM Retrieve any continuous memory DTCs. (See ON-BOARD DIAGNOSTIC TEST [MZR 2.5] .) Is the DTC P2299:00 present?	Yes	Go to the applicable DTC inspection. (Drive-by-wire control system operates with brake override system.) (See DTC P2299:00 [MZR 2.5] .)
1		No	Go to the next step.
2	INSPECT RELATED PART CONDITION Verify the following: Vacuum connection Restriction in the intake air system (such as the air cleaner element, fresh air duct) No air leakage from the intake air system No restriction of the intake air system Proper sealing of the intake manifold and components attached to the intake manifold: such as the EGR valve Fuel quality (such as proper octane, contamination, winter/summer blend) Are all the items normal?	Yes	Go to the next step.
2		No	Repair or replace the malfunctioning part according to the inspection results. Repeat Step 2.
3	VERIFY PCM DTC Retrieve any DTCs using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZR 2.5] .) Are there any DTCs displayed?	Yes	Go to the appropriate DTC inspection. (See DTC TABLE [MZR 2.5] .)
3		No	Go to the next step.
4	VERIFY IF MALFUNCTION CAUSE IS OVERHEATING Is the engine overheating?	Yes	Go to the symptom troubleshooting "NO.17 COOLING SYSTEM CONCERNS-OVERHEATING". (See NO.17 COOLING SYSTEM CONCERNS-OVERHEATING [MZR 2.5] .)
4		No	Go to the next step.
5	VERIFY CURRENT INPUT SIGNAL STATUS CAUTION: While performing this step, always operate the vehicle in a safe and lawful manner. When the M-MDS is used to observe monitor system status while driving, be sure to have another technician with you, or record the data in the M-MDS using the PID/DATA MONITOR AND RECORD capturing function and inspect later. Access the following PCM PIDs using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZR 2.5] .) APP1 APP2 RPM MAF TP REL IAT VSS Do the PIDs indicate correct values under the trouble condition? (See PCM INSPECTION [MZR 2.5] .)	Yes	Go to the next step.
5		No	APP1, APP2 PIDs are not specified: Inspect if the output signal APP sensor changes smoothly. (See ACCELERATOR PEDAL POSITION (APP) SENSOR INSPECTION [MZR 2.5] .) TP REL PID is not specified: Inspect if the output signal TP sensor changes smoothly. (See THROTTLE POSITION (TP) SENSOR INSPECTION [MZR 2.5] .) RPM PID is not specified: Inspect the CKP sensor and the related wiring harness for vibration or intermittent open/short circuit or both. (See CRANKSHAFT POSITION (CKP) SENSOR INSPECTION [MZR 2.5] .) MAF PID is not specified: Inspect for an intermittent open circuit of MAF sensor and the related wiring harness. (See MASS AIR FLOW (MAF) SENSOR INSPECTION [MZR 2.5] .) IAT PID is not specified: Inspect for air suction in the intake air system. If normal, inspect for an intermittent short circuit in the IAT sensor and related wiring harnesses. (See INTAKE AIR TEMPERATURE (IAT) SENSOR INSPECTION [MZR 2.5] .) VSS PID is not specified: Inspect for an intermittent open circuit in the VSS and related wiring harness. (See VEHICLE SPEED SENSOR (VSS) INSPECTION [FS5A-EL] .) Repair or replace the malfunctioning part according to the inspection result.
6	VISUALLY INSPECT CKP SENSOR AND PULSE WHEEL Visually inspect the CKP sensor and teeth of the crankshaft pulley. (See CRANKSHAFT POSITION (CKP) SENSOR INSPECTION [MZR 2.5] .) Are the CKP sensor and teeth of the crankshaft pulley normal?	Yes	Go to the next step.
6		No	Repair or replace the malfunctioning part according to the inspection result.
7	VERIFY SPARK PLUG CONDITION Verify the spark plug conditions when the spark plug removed in Step 8. (See SPARK PLUG INSPECTION [MZR 2.5] .) Is spark plug wet, covered with carbon or grayish white?	Yes	Spark plug is wet or covered with carbon: Inspect for fuel leakage from fuel injector. Spark plug is grayish white: Inspect the fuel injector for clogging. Repair or replace the malfunctioning part according to the inspection results.
7		No	Install the spark plugs on original cylinders. Go to the next step.
8	INSPECT THROTTLE BODY FOR CLOGGING Visually inspect the throttle valve. (See INTAKE-AIR SYSTEM REMOVAL/INSTALLATION [MZR 2.5] .) Are any foreign material adhere to around throttle valve?	Yes	Clean the throttle valve.
8		No	Go to the next step.
9	INSPECT DRIVE-BY-WIRE CONTROL SYSTEM OPERATION Perform the drive-by-wire control system operation inspection. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZR 2.5] .) Does the drive-by-wire control system function properly?	Yes	Go to the next step.
9		No	Repair or replace the malfunctioning part according to the inspection results.
10	INSPECT DEFORMED IN EXHAUST SYSTEM Visually inspect the exhaust system part. Is there any deformed exhaust system part?	Yes	Repair or replace the malfunctioning part according to the inspection results.
10		No	Go to the next step.
11	INSPECT FUEL LINE PRESSURE Inspect the fuel line pressure. (See FUEL LINE PRESSURE INSPECTION [MZR 2.5] .) Is the fuel line pressure correct?	Yes	Go to the next step.
11		No	Zero or low: Inspect the following: Fuel pump relay Fuel pump circuit Fuel line for clogging If there is no malfunction, replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [MZR 2.5] .) High: Replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [MZR 2.5] .)
12	INSPECT VARIABLE TUMBLE CONTROL OPERATION Perform the variable tumble control operation inspection. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZR 2.5] .) Does the variable tumble control function properly?	Yes	Go to the next step.
12		No	Repair or replace the malfunctioning part according to the inspection results.
13	INSPECT VARIABLE INTAKE AIR CONTROL OPERATION Perform the variable intake air control operation inspection. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZR 2.5] .) Does the VIS function properly?	Yes	Go to the next step.
13		No	Repair or replace the malfunctioning part according to the inspection results.
14	DETERMINE IF MALFUNCTION CAUSE IS A/C SYSTEM OR OTHER NOTE: The following test is for stall concerns with the A/C on. If other symptoms exist, go to the next step. Connect the pressure gauges to the A/C low side and high side pressure lines. Turn the A/C on and measure the low side and high side pressures. Are the pressures within the specifications? (See REFRIGERANT PRESSURE CHECK .)	Yes	Go to the next step.
14		No	If the A/C is always on: Go to the symptom troubleshooting "NO.24 A/C IS ALWAYS ON OR A/C COMPRESSOR RUNS CONTINUOUSLY". (See NO.24 A/C IS ALWAYS ON OR A/C COMPRESSOR RUNS CONTINUOUSLY [MZR 2.5] .) For other symptoms: Inspect the following: Refrigerant charging amount Cooling fan operation Repair or replace the malfunctioning part according to the inspection results.
15	INSPECT A/C CUT-OFF CONTROL SYSTEM OPERATION Perform the A/C cut-off operation inspection. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZR 2.5] .) Does the A/C cut-off function properly?	Yes	Go to the next step.
15		No	Inspect the A/C cut-off system components. Repair or replace the malfunctioning part according to the inspection results.
16	DETERMINE IF MALFUNCTION CAUSE IS EVAP CONTROL SYSTEM OR OTHER CAUTION: While performing this step, always operate the vehicle in a safe and lawful manner. Disconnect the vacuum hose between purge solenoid valve and intake manifold from the purge solenoid valve side. Plug the open end of the vacuum hose. Drive the vehicle. Does the engine condition improve?	Yes	Inspect the following: If the purge solenoid valve is stuck open. EVAP control system Repair or replace the malfunctioning part according to the inspection results.
16		No	Go to the next step.
17	VISUALLY INSPECT CMP SENSOR AND PULSE WHEEL Visually inspect the CMP sensor and teeth of the camshaft. (See CAMSHAFT POSITION (CMP) SENSOR INSPECTION [MZR 2.5] .) Are the CMP sensor and teeth of the camshaft normal?	Yes	Go to the next step.
17		No	Repair or replace the malfunctioning part according to the inspection results.
18	INSPECT EGR VALVE OPERATION Perform the EGR control system inspection. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZR 2.5] .) Is the EGR control system normal?	Yes	Go to the next step.
18		No	Repair or replace the malfunctioning part according to the inspection results.
19	INSPECT VARIABLE VALVE TIMING CONTROL SYSTEM OPERATION Inspect the variable valve timing control system operation. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZR 2.5] .) Does the variable valve timing control system operate properly?	Yes	Go to the next step.
19		No	Repair or replace the malfunctioning part according to the inspection results.
20	INSPECT ENGINE COMPRESSION Is the engine compression correct? (See COMPRESSION INSPECTION [MZR 2.5] .)	Yes	Go to the next step.
20		No	Inspect for cause. Repair or replace the malfunctioning part according to the inspection results.
21	INSPECT IF MALFUNCTION CAUSE IS PCV VALVE OR VALVE TIMING Inspect the PCV valve. (See POSITIVE CRANKCASE VENTILATION (PCV) VALVE INSPECTION [MZR 2.5] .) Is the PCV valve normal?	Yes	Inspect the following: Valve timing Internal transaxle part (ATX) Brake system for dragging Repair or replace the malfunctioning part according to the inspection results.
21		No	Replace the PCV valve and the oil separator as a single unit, then go to the next step. (See POSITIVE CRANKCASE VENTILATION (PCV) VALVE REMOVAL/INSTALLATION [MZR 2.5] .)
22	Verify test results. If normal, return to diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [MZR 2.5] .) 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, reprogram the PCM if a later calibration is available. Retest.

CAUTION
While performing this step, always operate the vehicle in a safe and lawful manner. When the M-MDS is used to observe monitor system status while driving, be sure to have another technician with you, or record the data in the M-MDS using the PID/DATA MONITOR AND RECORD capturing function and inspect later. Access the following PCM PIDs using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZR 2.5] .) APP1 APP2 RPM MAF TP REL IAT VSS Do the PIDs indicate correct values under the trouble condition? (See PCM INSPECTION [MZR 2.5] .)

CAUTION

While performing this step, always operate the vehicle in a safe and lawful manner. When the M-MDS is used to observe monitor system status while driving, be sure to have another technician with you, or record the data in the M-MDS using the PID/DATA MONITOR AND RECORD capturing function and inspect later. Access the following PCM PIDs using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZR 2.5] .) APP1 APP2 RPM MAF TP REL IAT VSS Do the PIDs indicate correct values under the trouble condition? (See PCM INSPECTION [MZR 2.5] .)

NOTE
The following test is for stall concerns with the A/C on. If other symptoms exist, go to the next step. Connect the pressure gauges to the A/C low side and high side pressure lines. Turn the A/C on and measure the low side and high side pressures. Are the pressures within the specifications? (See REFRIGERANT PRESSURE CHECK .)

CAUTION
While performing this step, always operate the vehicle in a safe and lawful manner. Disconnect the vacuum hose between purge solenoid valve and intake manifold from the purge solenoid valve side. Plug the open end of the vacuum hose. Drive the vehicle. Does the engine condition improve?

STEP	INSPECTION	RESULTS	ACTION
1	INSPECT COOLING SYSTEM FOR MALFUNCTION Access the PCM PID ECT using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZR 2.5] .) Verify the ECT PID is less than 116 °C {241 °F} during driving. Is the ECT PID less than the specification?	Yes	Go to the next step.
1		No	Inspect the cooling system for the cause of the overheating. Repair or replace the malfunctioning part according to the inspection results.
2	INSPECT IAT SENSOR AND MAF SENSOR SIGNALS CAUTION: While performing this step, always operate the vehicle in a safe and lawful manner. When the M-MDS is used to observe monitor system status while driving, be sure to have another technician with you, or record the data in the M-MDS using the PID/DATA MONITOR AND RECORD capturing function and inspect later. Access and monitor the PCM PIDs IAT and MAF using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZR 2.5] .) Are the PIDs normal? (See PCM INSPECTION [MZR 2.5] .)	Yes	Go to the next step.
2		No	IAT PID is not specified: Inspect the IAT sensor (See INTAKE AIR TEMPERATURE (IAT) SENSOR INSPECTION [MZR 2.5] .) MAF PID is not specified: Inspect the MAF sensor (See MASS AIR FLOW (MAF) SENSOR INSPECTION [MZR 2.5] .) Repair or replace the malfunctioning part according to the inspection results.
3	VERIFY PCM DTC Retrieve any DTCs using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZR 2.5] .) Are there any DTCs displayed?	Yes	Go to the appropriate DTC inspection. (See DTC TABLE [MZR 2.5] .)
3		No	Go to the next step.
4	INSPECT CMP SENSOR INSTALLATION Inspect the CMP sensor installation. Is the CMP sensor installed properly?	Yes	Go to the next step.
4		No	Install the CMP sensor properly. (See CAMSHAFT POSITION (CMP) SENSOR REMOVAL/INSTALLATION [MZR 2.5] .)
5	INSPECT CKP SENSOR AND PULSE WHEEL Inspect the CKP sensor and crankshaft pulley installation. Are CKP sensor and crankshaft pulley installed properly?	Yes	Go to the next step.
5		No	Install the CKP sensor and/or crankshaft pulley properly. (See CRANKSHAFT POSITION (CKP) SENSOR REMOVAL/INSTALLATION [MZR 2.5] .)
6	INSPECT ENGINE COMPRESSION Is the engine compression correct? (See COMPRESSION INSPECTION [MZR 2.5] .)	Yes	Go to the next step.
6		No	Inspect for cause. Repair or replace the malfunctioning part according to the inspection results.
7	INSPECT FUEL LINE PRESSURE Inspect the fuel line pressure. (See FUEL LINE PRESSURE INSPECTION [MZR 2.5] .) Is the fuel line pressure correct?	Yes	Go to the next step.
7		No	Zero or low: Inspect the following: Fuel pump relay Fuel pump circuit Fuel line for clogging If there is no malfunction, replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [MZR 2.5] .) High: Replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [MZR 2.5] .)
8	INSPECT KS Inspect the KS. (See KNOCK SENSOR (KS) INSPECTION [MZR 2.5] .) Is the KS normal?	Yes	Go to the next step.
8		No	Replace the KS. (See KNOCK SENSOR (KS) REMOVAL/INSTALLATION [MZR 2.5] .)
9	INSPECT IGNITION TIMING Inspect the ignition timing. (See ENGINE TUNE-UP [MZR 2.5] .) Is there any malfunction?	Yes	Repair or replace the malfunctioning part according to the inspection results.
9		No	Replace the fuel.
10	Verify test results. If normal, return to diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [MZR 2.5] .) 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, reprogram the PCM if a later calibration is available. Retest.

CAUTION
While performing this step, always operate the vehicle in a safe and lawful manner. When the M-MDS is used to observe monitor system status while driving, be sure to have another technician with you, or record the data in the M-MDS using the PID/DATA MONITOR AND RECORD capturing function and inspect later. Access and monitor the PCM PIDs IAT and MAF using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZR 2.5] .) Are the PIDs normal? (See PCM INSPECTION [MZR 2.5] .)

CAUTION

While performing this step, always operate the vehicle in a safe and lawful manner. When the M-MDS is used to observe monitor system status while driving, be sure to have another technician with you, or record the data in the M-MDS using the PID/DATA MONITOR AND RECORD capturing function and inspect later. Access and monitor the PCM PIDs IAT and MAF using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZR 2.5] .) Are the PIDs normal? (See PCM INSPECTION [MZR 2.5] .)

STEP	INSPECTION	RESULTS	ACTION
1	INSPECT RELATED PART CONDITION Inspect for the following: Air cleaner element for contamination ATF level (ATX) Fuel quality Coolant level Brake dragging Clutch slippage (MTX) Tire pressure Are all the items normal?	Yes	Go to the next step.
1		No	Repair or replace the malfunctioning part according to the inspection results. Repeat Step 1.
2	VERIFY PCM DTC Retrieve any DTCs using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZR 2.5] .) Are there any DTCs displayed?	Yes	Go to the appropriate DTC inspection. (See DTC TABLE [MZR 2.5] .)
2		No	Go to the next step.
3	INSPECT COOLING SYSTEM FOR MALFUNCTION Is any cooling system concern (overheating, runs cold) present?	Yes	Go to the symptom troubleshooting "NO.17 COOLING SYSTEM CONCERNS-OVERHEATING" or "NO.18 COOLING SYSTEM CONCERNS-RUNS COLD". (See NO.17 COOLING SYSTEM CONCERNS-OVERHEATING [MZR 2.5] .) (See NO.18 COOLING SYSTEM CONCERNS-RUNS COLD [MZR 2.5] .)
3		No	Go to the next step.
4	INSPECT COOLING FAN CONTROL SYSTEM OPERATION Perform the Cooling Fan Control System Inspection. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZR 2.5] .) Does the cooling fan control system operate properly?	Yes	Go to the next step.
4		No	Repair or replace the malfunctioning part according to the inspection results.
5	INSPECT IGNITION SYSTEM OPERATION Perform the Spark Test. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZR 2.5] .) Is a strong blue spark visible at each cylinder?	Yes	Go to the next step.
5		No	Repair or replace the malfunctioning part according to the inspection results.
6	INSPECT FUEL LINE PRESSURE Inspect the fuel line pressure. (See FUEL LINE PRESSURE INSPECTION [MZR 2.5] .) Is the fuel line pressure correct?	Yes	Go to the next step.
6		No	Zero or low: Inspect the following: Fuel pump relay Fuel pump circuit Fuel line for clogging If there is no malfunction, replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [MZR 2.5] .) High: Replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [MZR 2.5] .)
7	INSPECT VARIABLE TUMBLE CONTROL OPERATION Perform the variable tumble control operation inspection. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZR 2.5] .) Does the variable tumble control function properly?	Yes	Go to the next step.
7		No	Repair or replace the malfunctioning part according to the inspection results.
8	INSPECT VARIABLE VALVE TIMING CONTROL SYSTEM OPERATION Inspect the variable valve timing control system operation. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZR 2.5] .) Does the variable valve timing control system operate properly?	Yes	Go to the next step.
8		No	Repair or replace the malfunctioning part according to the inspection results.
9	INSPECT VARIABLE INTAKE AIR CONTROL OPERATION Perform the variable intake air control operation inspection. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZR 2.5] .) Does the variable intake air control function properly?	Yes	Go to the next step.
9		No	Repair or replace the malfunctioning part according to the inspection results.
10	INSPECT DEFORMED IN EXHAUST SYSTEM Visually inspect the exhaust system part. Is there any deformed exhaust system part?	Yes	Repair or replace the malfunctioning part according to the inspection results.
10		No	Go to the next step.
11	INSPECT MAF SENSOR FOR CONTAMINATION Inspect the MAF sensor for contamination. Is there any contamination?	Yes	Replace the MAF/IAT sensor. (See INTAKE-AIR SYSTEM REMOVAL/INSTALLATION [MZR 2.5] .)
11		No	Go to the next step.
12	INSPECT ENGINE COMPRESSION Is the engine compression correct? (See COMPRESSION INSPECTION [MZR 2.5] .)	Yes	Go to the next step.
12		No	Inspect for cause. Repair or replace the malfunctioning part according to the inspection results.
13	INSPECT IF MALFUNCTION CAUSE IS PCV VALVE OR VALVE TIMING Inspect the PCV valve. (See POSITIVE CRANKCASE VENTILATION (PCV) VALVE INSPECTION [MZR 2.5] .) Is the PCV valve normal?	Yes	Inspect the valve timing. Repair or replace the malfunctioning part according to the inspection results.
13		No	Replace the PCV valve and the oil separator as a single unit, then go to the next step. (See POSITIVE CRANKCASE VENTILATION (PCV) VALVE REMOVAL/INSTALLATION [MZR 2.5] .)
14	Verify test results. If normal, return to diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [MZR 2.5] .) 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, reprogram the PCM if a later calibration is available. Retest.

STEP	INSPECTION	RESULTS	ACTION
1	INSPECT RELATED PART CONDITION Inspect the following: Vacuum lines for leakage or blockage Electrical connections Proper maintenance schedule followed Intake air system and air cleaner element concerns: obstructions, leakage or soiling Are all items normal?	Yes	Go to the next step.
1		No	Repair or replace the malfunctioning part according to the inspection results. Repeat Step 1.
2	VERIFY PCM DTC Retrieve any DTCs using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZR 2.5] .) Are there any DTCs displayed?	Yes	Go to the appropriate DTC inspection. (See DTC TABLE [MZR 2.5] .)
2		No	Go to the next step.
3	VERIFY IF MALFUNCTION INCLUDES DRIVEABILITY Is any other drivability concern present?	Yes	Go to the appropriate symptom troubleshooting.
3		No	Go to the next step.
4	INSPECT COOLING SYSTEM FOR MALFUNCTION Access the PCM PID ECT using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZR 2.5] .) Warm up the engine and idle it. Is the ECT PID normal? (See PCM INSPECTION [MZR 2.5] .)	Yes	Go to the next step.
4		No	Inspect the following: Coolant leakage Cooling fan and condenser fan operation Thermostat operation Repair or replace the malfunctioning part according to the inspection results.
5	INSPECT FUEL CAP Inspect the fuel-filler cap. (See FUEL-FILLER CAP INSPECTION [MZR 2.5] .) Is there any leakage at the fuel-filler cap?	Yes	Replace the fuel-filler cap.
5		No	Go to the next step.
6	INSPECT CURRENT A/F SENSOR SIGNAL Inspect the A/F sensor. (See AIR FUEL RATIO (A/F) SENSOR INSPECTION [MZR 2.5] .) Is the A/F sensor normal?	Yes	Go to the next step.
6		No	Inspect for following: Exhaust gas leakage between exhaust manifold and A/F sensor Loose installation of A/F sensor Repair or replace the malfunctioning part according to the inspection results. (See EXHAUST SYSTEM REMOVAL/INSTALLATION [MZR 2.5] .) If there are no malfunctions detected, replace the A/F sensor. (See AIR FUEL RATIO (A/F) SENSOR REMOVAL/INSTALLATION [MZR 2.5] .)
7	INSPECT IGNITION SYSTEM OPERATION Perform the Spark Test. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZR 2.5] .) Is a strong blue spark visible at each cylinder?	Yes	Go to the next step.
7		No	Repair or replace the malfunctioning part according to the inspection results.
8	INSPECT FUEL LINE PRESSURE Inspect the fuel line pressure. (See FUEL LINE PRESSURE INSPECTION [MZR 2.5] .) Is the fuel line pressure correct?	Yes	Go to the next step.
8		No	Zero or low: Inspect the following: Fuel pump relay Fuel pump circuit Fuel line for clogging If there is no malfunction, replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [MZR 2.5] .) High: Replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [MZR 2.5] .)
9	DETERMINE IF MALFUNCTION CAUSE IS CHARCOAL CANISTER OR FUEL TANK VENT SYSTEM Inspect for fuel saturation inside the charcoal canister. Is there an excess amount of liquid fuel present in canister?	Yes	Replace the charcoal canister. (See CHARCOAL CANISTER, CANISTER VENT (CV) SOLENOID VALVE, AIR FILTER COMPONENT REMOVAL/INSTALLATION [MZR 2.5] .)
9		No	Inspect the fuel tank vent system. (See FUEL TANK INSPECTION [MZR 2.5] .) Repair or replace the malfunctioning part according to the inspection results, then go to the next step.
10	INSPECT DEFORMED IN EXHAUST SYSTEM Visually inspect the exhaust system part. Is there any deformed exhaust system part?	Yes	Repair or replace the malfunctioning part according to the inspection results.
10		No	Go to the next step.
11	INSPECT TWC Inspect the TWC. (See EXHAUST SYSTEM INSPECTION [MZR 2.5] .) Is the TWC normal?	Yes	Go to the next step.
11		No	Replace the TWC. (See EXHAUST SYSTEM REMOVAL/INSTALLATION [MZR 2.5] .)
12	INSPECT EGR VALVE OPERATION Perform the EGR control system inspection. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZR 2.5] .) Is the EGR system normal?	Yes	Go to the next step.
12		No	Repair or replace the malfunctioning part according to the inspection results.
13	INSPECT ENGINE COMPRESSION Is the engine compression correct? (See COMPRESSION INSPECTION [MZR 2.5] .)	Yes	Go to the next step.
13		No	Inspect for cause. Repair or replace the malfunctioning part according to the inspection results.
14	INSPECT IF MALFUNCTION CAUSE IS PCV VALVE OR VALVE TIMING Inspect the PCV valve. (See POSITIVE CRANKCASE VENTILATION (PCV) VALVE INSPECTION [MZR 2.5] .) Is the PCV valve normal?	Yes	Inspect the valve timing. Repair or replace the malfunctioning part according to the inspection results.
14		No	Replace the PCV valve and the oil separator as a single unit, then go to the next step. (See POSITIVE CRANKCASE VENTILATION (PCV) VALVE REMOVAL/INSTALLATION [MZR 2.5] .)
15	Verify test results. If normal, return to diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [MZR 2.5] .) 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, reprogram the PCM if a later calibration is available. Retest.

STEP	INSPECTION	RESULTS	ACTION
1	INSPECT RELATED PART CONDITION Inspect for the following: External leakage Proper dipstick Proper engine oil viscosity Are all items normal?	Yes	Go to the next step.
1		No	Repair or replace the malfunctioning part according to the inspection results. Repeat Step 1.
2	INSPECT IF MALFUNCTION CAUSE IS PCV VALVE OR OTHER Inspect the PCV valve. (See POSITIVE CRANKCASE VENTILATION (PCV) VALVE INSPECTION [MZR 2.5] .) Is the PCV valve normal?	Yes	Inspect the internal engine parts such as valves, valve guides, valve stem seals, cylinder head drain passage, and piston rings. Repair or replace the malfunctioning part according to the inspection results.
2		No	Replace the PCV valve and the oil separator as a single unit, then go to the next step. (See POSITIVE CRANKCASE VENTILATION (PCV) VALVE REMOVAL/INSTALLATION [MZR 2.5] .)
3	Verify test results. If normal, return to diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [MZR 2.5] .) 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, reprogram the PCM if a later calibration is available. Retest.

STEP	INSPECTION	RESULTS	ACTION
1	INSPECT RELATED PART CONDITION Inspect the following: Engine coolant level Coolant leakage Water and anti-freeze mixture Radiator condition Collapsed or restricted radiator hoses Radiator pressure cap Overflow system Fan rotational direction Fuses Are all items normal?	Yes	Go to the next step.
1		No	Repair or replace the malfunctioning part according to the inspection results. Repeat Step 1.
2	VERIFY PCM DTC Retrieve any DTCs using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZR 2.5] .) Are there any DTCs displayed?	Yes	Go to the appropriate DTC inspection. (See DTC TABLE [MZR 2.5] .)
2		No	Go to the next step.
3	DETERMINE IF MALFUNCTION CAUSE IS A/C SYSTEM OR OTHER Start the engine and idle it. Verify state of the A/C compressor while turning on and off the air conditioner by switching the control panel. Does the A/C compressor engage and disengage according to air control panel switching?	Yes	Go to the next step.
3		No	If the A/C compressor is not engaged always: Go to the symptom troubleshooting "NO.23 A/C DOES NOT WORK SUFFICIENTLY". (See NO.23 A/C DOES NOT WORK SUFFICIENTLY [MZR 2.5] .) If the A/C compressor is engaged always: Go to the symptom troubleshooting "NO.24 A/C IS ALWAYS ON OR A/C COMPRESSOR RUNS CONTINUOUSLY". (See NO.24 A/C IS ALWAYS ON OR A/C COMPRESSOR RUNS CONTINUOUSLY [MZR 2.5] .)
4	INSPECT COOLING FAN CONTROL SYSTEM OPERATION Inspect the cooling fan control system operation. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZR 2.5] .) Does the cooling fan control system function properly?	Yes	Go to the next step.
4		No	Repair or replace the malfunctioning part according to the inspection results.
5	INSPECT DRIVE BELT Is the drive belt normal? (See DRIVE BELT INSPECTION [MZR 2.5] .)	Yes	Go to the next step.
5		No	Replace the drive belt. (See DRIVE BELT REMOVAL/INSTALLATION [MZR 2.5] .)
6	INSPECT COOLANT LEAKAGE AT HEATER UNIT Is there leakage around the climate control unit in the passenger compartment?	Yes	Inspect the heater for leakage. Repair or replace the malfunctioning part according to the inspection results.
6		No	Go to the next step.
7	INSPECT COOLANT LEAKAGE AT COOLING SYSTEM PART Is there leakage at the coolant hoses and/or radiator?	Yes	Repair or replace the malfunctioning part according to the inspection results.
7		No	Go to the next step.
8	INSPECT ECT SENSOR SIGNAL Access the PCM PID ECT using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZR 2.5] .) Compare the ECT PID and the water temperature gauge on the instrument cluster reading. Is the ECT PID same as water temperature gauge reading?	Yes	Go to the next step.
8		No	Inspect the water temperature gauge. (See INSTRUMENT CLUSTER INSPECTION .) Repair or replace the malfunctioning part according to the inspection results. If the water temperature gauge is normal, inspect the ECT sensor. (See ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION [MZR 2.5] .) Repair or replace the malfunctioning part according to the inspection results.
9	INSPECT IF MALFUNCTION CAUSE IS THERMOSTAT OR CYLINDER BLOCK Cool down the engine. Remove thermostat and inspect operation. (See THERMOSTAT REMOVAL/INSTALLATION [MZR 2.5] .) (See THERMOSTAT INSPECTION [MZR 2.5] .) Is the thermostat normal?	Yes	Engine coolant temperature and thermostat are normal. Inspect the engine block for leakage or blockage. Repair or replace the malfunctioning part according to the inspection results.
9		No	Replace the thermostat. (See THERMOSTAT REMOVAL/INSTALLATION [MZR 2.5] .)
10	Verify test results. If normal, return to diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [MZR 2.5] .) 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, reprogram the PCM if a later calibration is available. Retest.

STEP	INSPECTION	RESULTS	ACTION
1	DETERMINE IF MALFUNCTION CAUSE IS HVAC SYSTEM OR ENGINE Is the customer complaint "Lack of passenger compartment heat" only?	Yes	Inspect A/C and heater system. Repair or replace the malfunctioning part according to the inspection results.
1		No	Go to the next step.
2	VERIFY IDLE SPEED Does the engine speed continue at fast idle?	Yes	Go to the symptom troubleshooting "NO.9 FAST IDLE/RUNS ON". (See NO.9 FAST IDLE/RUNS ON [MZR 2.5] .)
2		No	Go to the next step.
3	INSPECT COOLING FAN CONTROL SYSTEM OPERATION Inspect the cooling fan control system operation. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZR 2.5] .) Does the cooling fan control system function properly?	Yes	Go to the next step.
3		No	Repair or replace the malfunctioning part according to the inspection results.
4	INSPECT THERMOSTAT Cool down the engine. Remove the thermostat and inspect operation. (See THERMOSTAT REMOVAL/INSTALLATION [MZR 2.5] .) (See THERMOSTAT INSPECTION [MZR 2.5] .) Is the thermostat normal?	Yes	Inspect the water temperature gauge. (See INSTRUMENT CLUSTER INSPECTION .) Repair or replace the malfunctioning part according to the inspection results. If the water temperature gauge is normal, inspect the ECT sensor. (See ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION [MZR 2.5] .) Repair or replace the malfunctioning part according to the inspection results.
4		No	Replace the thermostat. (See THERMOSTAT REMOVAL/INSTALLATION [MZR 2.5] .)
5	Verify test results. If normal, return to diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [MZR 2.5] .) 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, reprogram the PCM if a later calibration is available. Retest.

STEP	INSPECTION	RESULTS	ACTION
1	VERIFY EXHAUST GAS COLOR What color is the smoke coming from the exhaust system?	Blue	Burning oil is indicated. Go to the next step.
		White	Water in the combustion is indicated. Go to Step 3.
		Black	Rich fuel mixture is indicated. Go to Step 4.
2	INSPECT IF MALFUNCTION CAUSE IS PCV VALVE OR OTHER Inspect the PCV valve. (See POSITIVE CRANKCASE VENTILATION (PCV) VALVE INSPECTION [MZR 2.5] .) Is the PCV valve normal?	Yes	Inspect for the following: Damaged valve guide, stems or valve seals Blocked oil drain passage in the cylinder head Piston ring is not seated, seized or worn. Damaged cylinder bore Repair or replace the malfunctioning part according to the inspection results. If other drivability symptoms are present, return to the diagnostic index to service any additional symptoms.
2		No	Replace the PCV valve and the oil separator as a single unit, then go to the next step. (See POSITIVE CRANKCASE VENTILATION (PCV) VALVE REMOVAL/INSTALLATION [MZR 2.5] .)
3	INSPECT COOLING SYSTEM FOR LEAKAGE Does the cooling system hold pressure?	Yes	Inspect for the following: Cylinder head gasket leakage Intake manifold gasket leakage Cracked or porous engine block Repair or replace the malfunctioning part according to the inspection results. If other drivability symptoms are present, return to diagnostic index to service any additional symptoms.
3		No	Inspect for cause. Repair or replace the malfunctioning part according to the inspection results.
4	INSPECT INTAKE AIR SYSTEM Inspect for the following: Air cleaner restriction Collapsed or restricted intake air system Restricted fuel return line Are all items normal?	Yes	Go to the next step.
4		No	Repair or replace the malfunctioning part according to the inspection results. Repeat Step 4.
5	VERIFY PCM DTC Retrieve any DTCs using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZR 2.5] .) Are there any DTCs displayed?	Yes	Go to the appropriate DTC inspection. (See DTC TABLE [MZR 2.5] .)
5		No	Go to the next step.
6	VERIFY CURRENT INPUT SIGNAL STATUS CAUTION: While performing this step, always operate the vehicle in a safe and lawful manner. When the M-MDS is used to observe monitor system status while driving, be sure to have another technician with you, or record the data in the M-MDS using the PID/DATA MONITOR AND RECORD capturing function and inspect later. Access the following PCM PIDs using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZR 2.5] .) APP1 APP2 ECT IAT MAF MAP O2S11 O2S12 TP1 TP2 VSS Monitor the PIDs under the black smoke appeared engine condition. Do the PIDs indicate normal according to engine conditions? (See PCM INSPECTION [MZR 2.5] .)	Yes	Go to the next step.
6		No	APP1, APP2 PIDs are not specified: Inspect if the output signal APP sensor changes smoothly. (See ACCELERATOR PEDAL POSITION (APP) SENSOR INSPECTION [MZR 2.5] .) ECT PID is not as specified: Inspect for an intermittent open circuit of the ECT sensor and the related wiring harness. (See ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION [MZR 2.5] .) IAT PID is not specified: Inspect for an intermittent open circuit of the IAT sensor and the related wiring harness. (See INTAKE AIR TEMPERATURE (IAT) SENSOR INSPECTION [MZR 2.5] .) MAF PID is not specified: Inspect for an intermittent open circuit of MAF sensor and the related wiring harness. (See MASS AIR FLOW (MAF) SENSOR INSPECTION [MZR 2.5] .) MAP PID is not as specified: Inspect for an intermittent open circuit of the MAP sensor and the related wiring harness. (See MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR INSPECTION [MZR 2.5] .) O2S11 PID is not as specified: Inspect for an intermittent open circuit of the A/F sensor and the related wiring harness. (See AIR FUEL RATIO (A/F) SENSOR INSPECTION [MZR 2.5] .) O2S12 PID is not as specified: Inspect for an intermittent open circuit of the HO2S and the related wiring harness. (See HEATED OXYGEN SENSOR (HO2S) INSPECTION [MZR 2.5] .) TP1, TP2 PIDs are not as specified: Inspect if the output signal from the TP sensor changes smoothly. (See THROTTLE POSITION (TP) SENSOR INSPECTION [MZR 2.5] .) VSS PID is not specified: Inspect for an intermittent open circuit in the VSS and related wiring harness. (See VEHICLE SPEED SENSOR (VSS) INSPECTION [FS5A-EL] .) Repair or replace the malfunctioning part according to the inspection result.
7	INSPECT FUEL LINE PRESSURE Inspect the fuel line pressure. (See FUEL LINE PRESSURE INSPECTION [MZR 2.5] .) Is the fuel line pressure correct?	Yes	Go to the next step.
7		No	Zero or low: Inspect the following: Fuel pump relay Fuel pump circuit Fuel line for clogging If there is no malfunction, replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [MZR 2.5] .) High: Replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [MZR 2.5] .)
8	INSPECT IGNITION SYSTEM OPERATION Perform the Spark Test. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZR 2.5] .) Is a strong blue spark visible at each cylinder?	Yes	Go to the next step.
8		No	Repair or replace the malfunctioning part according to the inspection results.
9	INSPECT CMP SENSOR Inspect the CMP sensor. (See CAMSHAFT POSITION (CMP) SENSOR INSPECTION [MZR 2.5] .) Is the CMP sensor normal?	Yes	Go to the next step.
9		No	Repair or replace the malfunctioning part according to the inspection results.
10	INSPECT ENGINE COMPRESSION Measure the compression pressure for each cylinder. (See COMPRESSION INSPECTION [MZR 2.5] .) Are compression pressures within specified?	Yes	Inspect the fuel injector for each cylinder. (See FUEL INJECTOR INSPECTION [MZR 2.5] .) Repair or replace the malfunctioning part according to the inspection results.
10		No	Inspect for the followings: Damaged the valve seat Worn valve stem and valve guide Worn or stuck piston ring Worn piston, piston ring or cylinder Improper valve timing Repair or replace the malfunctioning part according to the inspection results.
11	Verify test results. If normal, return to diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [MZR 2.5] .) 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, reprogram the PCM if a later calibration is available. Retest.

CAUTION
While performing this step, always operate the vehicle in a safe and lawful manner. When the M-MDS is used to observe monitor system status while driving, be sure to have another technician with you, or record the data in the M-MDS using the PID/DATA MONITOR AND RECORD capturing function and inspect later. Access the following PCM PIDs using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZR 2.5] .) APP1 APP2 ECT IAT MAF MAP O2S11 O2S12 TP1 TP2 VSS Monitor the PIDs under the black smoke appeared engine condition. Do the PIDs indicate normal according to engine conditions? (See PCM INSPECTION [MZR 2.5] .)

CAUTION

While performing this step, always operate the vehicle in a safe and lawful manner. When the M-MDS is used to observe monitor system status while driving, be sure to have another technician with you, or record the data in the M-MDS using the PID/DATA MONITOR AND RECORD capturing function and inspect later. Access the following PCM PIDs using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZR 2.5] .) APP1 APP2 ECT IAT MAF MAP O2S11 O2S12 TP1 TP2 VSS Monitor the PIDs under the black smoke appeared engine condition. Do the PIDs indicate normal according to engine conditions? (See PCM INSPECTION [MZR 2.5] .)

STEP	INSPECTION	RESULTS	ACTION
1	INSPECT FUEL LINE PRESSURE Inspect the fuel line pressure. (See FUEL LINE PRESSURE INSPECTION [MZR 2.5] .) Is the fuel line pressure correct?	Yes	Go to the next step.
1		No	Zero or low: Inspect the following: Fuel pump relay Fuel pump circuit Fuel line for clogging If there is no malfunction, replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [MZR 2.5] .) High: Replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [MZR 2.5] .)
2	INSPECT FUEL SYSTEM FOR FUEL LEAKAGE Visually inspect for fuel leakage at the fuel injector O-ring and fuel line. Service if necessary. Is the fuel line pressure held after ignition is off? (See FUEL LINE PRESSURE INSPECTION [MZR 2.5] .)	Yes	Go to the next step.
2		No	Inspect the fuel injector. (See FUEL INJECTOR INSPECTION [MZR 2.5] .) If the fuel injector is normal, replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [MZR 2.5] .)
3	INSPECT FUEL TANK VENT SYSTEM Inspect the following: Blockage/restriction or an open circuit in the wiring harness between engine vacuum port and charcoal canister Blockage in the fuel tank vent system Is there any malfunction?	Yes	Replace the vacuum hose.
3		No	Go to the next step.
4	INSPECT PURGE SOLENOID VALVE Inspect the purge solenoid valve. (See PURGE SOLENOID VALVE INSPECTION [MZR 2.5] .) Is the solenoid operating properly?	Yes	Go to the next step.
4		No	Replace the purge solenoid valve. (See PURGE SOLENOID VALVE REMOVAL/INSTALLATION [MZR 2.5] .)
5	VERIFY PCM DTC Retrieve any DTCs using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZR 2.5] .) Are there any DTCs displayed?	Yes	Go to the appropriate DTC inspection. (See DTC TABLE [MZR 2.5] .)
5		No	Inspect the charcoal canister for fuel saturation. If an excess amount of liquid fuel is present, replace the charcoal canister. (See CHARCOAL CANISTER, CANISTER VENT (CV) SOLENOID VALVE, AIR FILTER COMPONENT REMOVAL/INSTALLATION [MZR 2.5] .)
6	Verify test results. If normal, return to diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [MZR 2.5] .) 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, reprogram the PCM if a later calibration is available. Retest.

STEP	INSPECTION	RESULTS	ACTION
1	VERIFY IF THERE IS SQUEAL, CLICK, OR CHIRP SOUND Is a squealing, click or chirping sound present?	Yes	Inspect the followings: Engine oil level Drive belt tension Splash shield or under cover looseness Solenoid valve installation Auto tensioner bearing damaged Generator installation Repair or replace the malfunctioning part according to the inspection results.
1		No	Go to the next step.
2	VERIFY IF THERE IS RUMBLE OR GRIND SOUND Is a rumbling or grinding noise present?	Yes	Inspect the followings: Drive belt tension Loose parts in engine compartment Power steering fluid level Repair or replace the malfunctioning part according to inspection result. If normal, perform the power steering fluid line air bleeding. (See AIR BLEEDING .)
2		No	Go to the next step.
3	VERIFY IF THERE IS RATTLE SOUND Is a rattling noise present?	Yes	Inspect the rattling location for loose parts. Repair or replace the malfunctioning part according to the inspection results.
3		No	Go to the next step.
4	VERIFY IF THERE IS HISS SOUND Is a hissing noise present?	Yes	Inspect the following: Vacuum leakage Spark plug looseness Intake air system leakage Repair or replace the malfunctioning part according to the inspection results.
4	VERIFY IF THERE IS HISS SOUND Is a hissing noise present?	No	Go to the next step.
5	VERIFY IF THERE IS RAP OR ROAR SOUND Is a rapping or roar noise present?	Yes	Inspect for looseness in the following: Dynamic dumper Intake air system Exhaust system Repair or replace the malfunctioning part according to the inspection results.
5		No	Go to the next step.
6	VERIFY IF THERE IS KNOCK SOUND Is a knocking noise present?	Yes	Go to the symptom troubleshooting "NO.13 KNOCKING/PINGING-ACCELERATION/CRUISE". (See NO.13 KNOCKING/PINGING-ACCELERATION/CRUISE [MZR 2.5] .)
6	VERIFY IF THERE IS KNOCK SOUND Is a knocking noise present?	No	If noise comes from engine internal: Inspect the following: Friction gear Timing chain Tappet noise Valve clearance Variable tumble control system operation Variable valve timing control actuator Repair or replace the malfunctioning part according to the inspection results.
7	Verify test results. If normal, return to diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [MZR 2.5] .) 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, reprogram the PCM if a later calibration is available. Retest.

STEP	INSPECTION	RESULTS	ACTION
1	VERIFY PART INSTALLATION CONDITION Inspect the following components for loose attaching bolts or worn parts: Cooling fan Drive belt and pulleys Generator Engine mounts Exhaust system mounts Are all items normal?	Yes	Inspect the following systems: Wheels ATX MTX Driveline Suspension Repair or replace the malfunctioning part according to the inspection results.
1		No	Readjust or retighten engine mount installation position. Service if necessary for other parts.
2	Verify test results. If normal, return to diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [MZR 2.5] .) 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, reprogram the PCM if a later calibration is available. Retest.

STEP	INSPECTION	RESULTS	ACTION
1	VERIFY PCM AND CLIMATE CONTROL UNIT DTC Retrieve the PCM and climate control unit DTCs using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZR 2.5] .) (See DTC DISPLAY .) Are there any DTCs displayed?	Yes	Go to the appropriate DTC inspection. (See DTC TABLE [MZR 2.5] .) (See DTC TABLE.)
1		No	Go to the next step.
2	DETERMINE IF MALFUNCTION CAUSE IS A/C REQUEST SIGNAL OR MAGNET CLUTCH DRIVE SIGNAL Access the PCM PID ACCS using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZR 2.5] .) Start the engine and idle it. Turn the PID ACCS to ON from OFF using the M-MDS simulation function. Is the magnetic clutch engaged?	Yes	Go to the next step.
2		No	Go to Step 13.
3	DETERMINE IF MALFUNCTION CAUSE IS EVAPORATOR TEMPERATURE SIGNAL OR OTHER Access the PCM PID AC_REQ using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZR 2.5] .) Start the engine and idle it. Monitor the PID AC_REQ while turning on and off the air conditioner by switching the control panel. Does the PID change according to air control panel switching? (See PCM INSPECTION [MZR 2.5] .)	Yes	Go to the next step.
3		No	Full-auto air conditioner: Go to Step 6. Manual air conditioner: Go to Step 7.
4	DETERMINE IF MALFUNCTION CAUSE IS REFRIGERANT PRESSURE SENSOR OR OTHER Access the PCM PID COLP using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZR 2.5] .) Monitor the COLP PID while turning on and off the air conditioner by switching the control panel. Is the PID value normal? (See PCM INSPECTION [MZR 2.5] .)	Yes	Go to Step 13.
4		No	Go to the next step.
5	INSPECT REFRIGERANT PRESSURE SENSOR Inspect the refrigerant pressure sensor. (See REFRIGERANT PRESSURE SENSOR INSPECTION [FULL-AUTO AIR CONDITIONER] .) (See REFRIGERANT PRESSURE SENSOR INSPECTION [MANUAL AIR CONDITIONER] .) Is the refrigerant pressure sensor normal?	Yes	Inspect for following: Refrigerant charging amount Magnetic clutch for seizure Repair or replace the malfunctioning part according to the inspection results.
5		No	Inspect the following: A/C switch is stuck open. pen circuit in wiring harness between the refrigerant pressure sensor and PCM terminal 1J Open circuit in wiring harness between front blower motor and resistor (If the front blower motor does not operate.) Evaporator temperature sensor and climate control unit Repair or replace the malfunctioning part according to the inspection results.
6	DETERMINE IF MALFUNCTION CAUSE IS EVAPORATOR TEMPERATURE SENSOR OR OTHER (FULL-AUTO AIR CONDITIONER) Access the climate control unit PID EVAP_TEMP using the M-MDS. (See PID/DATA MONITOR DISPLAY .) Monitor the EVAP_TEMP PID while turning on and off the air conditioner by switching the control panel. Is the PID value normal?	Yes	Go to Step 9.
6		No	Go to Step 8.
7	DETERMINE IF MALFUNCTION CAUSE IS EVAPORATOR TEMPERATURE SENSOR OR OTHER (MANUAL AIR CONDITIONER) Remove the climate control unit. (See CLIMATE CONTROL UNIT REMOVAL/INSTALLATION [MANUAL AIR CONDITIONER] .) Reconnect the climate control unit connector. Measure the voltage at the climate control unit terminal 1P. Is the voltage within the specified? (See CLIMATE CONTROL UNIT INSPECTION [MANUAL AIR CONDITIONER] .)	Yes	Go to Step 11.
7		No	Go to the next step.
8	INSPECT EVAPORATOR TEMPERATURE SENSOR Inspect the evaporator temperature sensor. (See EVAPORATOR TEMPERATURE SENSOR INSPECTION [MANUAL AIR CONDITIONER] .) (See EVAPORATOR TEMPERATURE SENSOR INSPECTION [FULL-AUTO AIR CONDITIONER] .) Is the evaporator temperature sensor normal?	Yes	Inspect for open or short circuit between evaporator temperature sensor and climate control unit. Repair or replace suspected wiring harness and connector. If normal, replace the climate control unit. (See CLIMATE CONTROL UNIT REMOVAL/INSTALLATION [FULL-AUTO AIR CONDITIONER] .) (See CLIMATE CONTROL UNIT REMOVAL/INSTALLATION [MANUAL AIR CONDITIONER] .)
8		No	Replace the evaporator temperature sensor. (See EVAPORATOR TEMPERATURE SENSOR REMOVAL/INSTALLATION [MANUAL AIR CONDITIONER] .) (See EVAPORATOR TEMPERATURE SENSOR REMOVAL/INSTALLATION [FULL-AUTO AIR CONDITIONER] .)
9	DETERMINE IF MALFUNCTION CAUSE IS INSTRUMENT CLUSTER OR OTHER (FULL-AUTO AIR CONDITIONER) Verify the information display indication of A/C system while turning on and off the air conditioner by switching the control panel. Does the information display indicate properly?	Yes	Replace the instrument cluster. (Instrument cluster does not receive A/C request signal from climate control unit or transmit it to PCM.) (See INSTRUMENT CLUSTER REMOVAL/INSTALLATION .)
9		No	Go to the next step.
10	DETERMINE IF MALFUNCTION CAUSE IS CLIMATE CONTROL UNIT OR OTHER (FULL-AUTO AIR CONDITIONER) Inspect the information display. (See INFORMATION DISPLAY INPUT/OUTPUT CHECK MODE .) Is there any malfunction?	Yes	Repair or replace the malfunctioning part according to the inspection results.
10		No	Replace the climate control unit. (A/C switch malfunction or climate control unit does not determine A/C request or transmit the A/C request signal.) (See CLIMATE CONTROL UNIT REMOVAL/INSTALLATION [FULL-AUTO AIR CONDITIONER] .)
11	DETERMINE IF MALFUNCTION CAUSE IS INSTRUMENT CLUSTER OR OTHER (MANUAL AIR CONDITIONER) Remove the climate control unit. (See CLIMATE CONTROL UNIT REMOVAL/INSTALLATION [MANUAL AIR CONDITIONER] .) Reconnect the climate control unit connector. Start the engine and idle it. Measure the voltage at the climate control unit terminal 1L while turning on and off the air conditioner by switching the control panel. Is the voltage change in specified according to air control panel switching? (See CLIMATE CONTROL UNIT INSPECTION [MANUAL AIR CONDITIONER] .) Specification Turn on the A/C: Below 1.0 V Turn off the A/C: Approx. 5 V	Yes	Replace the instrument cluster. (Instrument cluster does not receive A/C request signal from climate control unit or transmit it to PCM.) (See INSTRUMENT CLUSTER REMOVAL/INSTALLATION .)
11		No	Go to the next step.
12	DETERMINE IF MALFUNCTION CAUSE IS A/C REQUEST SIGNAL RELATED WIRING HARNESS OR CLIMATE CONTROL UNIT (MANUAL AIR CONDITIONER) Inspect for open or short circuit between climate control unit terminal 1L and instrument cluster terminal 1A. Is there any open or short circuit detected?	Yes	Repair or replace suspected wiring harness and connector.
12		No	Replace the climate control unit. (A/C switch malfunction or climate control unit does not determine A/C request or transmit the A/C request signal.) (See CLIMATE CONTROL UNIT REMOVAL/INSTALLATION [MANUAL AIR CONDITIONER] .)
13	DETERMINE IF MALFUNCTION CAUSE IS A/C CONTROL SIGNAL OR MAGNETIC CLUTCH Start the engine and idle it. Turn the PID ACCS to ON from OFF using the M-MDS simulation function. Measure the voltage between magnetic clutch terminal A and body ground. Is the voltage specified? Specification 10.5 V or more	Yes	Go to the next step.
13		No	Go to Step 15.
14	INSPECT MAGNETIC CLUTCH GROUND CIRCUIT FOR OPEN CIRCUIT Verify continuity between magnetic clutch terminal A and body ground. Is there any continuity?	Yes	Replace the A/C compressor. (See A/C COMPRESSOR REMOVAL/INSTALLATION .)
14		No	Repair or replace suspected wiring harness and/or poor contact ground points.
15	INSPECT A/C RELAY Inspect the A/C relay. (See RELAY INSPECTION .) Is the A/C relay normal?	Yes	Go to the next step.
15		No	Replace the A/C relay.
16	INSPECT A/C RELAY CONTROL CIRCUIT FOR OPEN CIRCUIT Switch the ignition to off. Disconnect the A/C relay and PCM connectors. Verify continuity between A/C relay and PCM terminal 1I (wiring harness-side). Is there any continuity?	Yes	Inspect for open circuit in followings: Between ignition switch (IG2) (1) /IG2 relay (2) and A/C relay Between battery positive terminal and A/C relay Between A/C relay and magnetic clutch Repair or replace suspected wiring harness and connector.
16		No	Repair or replace suspected wiring harness and connector.
17	Verify test results. If normal, return to diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [MZR 2.5] .) 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, reprogram the PCM if a later calibration is available. Retest.
(1) Without advanced keyless entry and push button start system (2) With advanced keyless entry and push button start system

(1)	Without advanced keyless entry and push button start system

(2)	With advanced keyless entry and push button start system

STEP	INSPECTION	RESULTS	ACTION
1	VERIFY PCM AND CLIMATE CONTROL UNIT DTC Retrieve the PCM and climate control unit DTCs using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZR 2.5] .) (See DTC DISPLAY .) Are there any DTCs displayed?	Yes	Go to the appropriate DTC inspection. (See DTC TABLE [MZR 2.5] .) (See DTC TABLE.)
1		No	Go to the next step.
2	DETERMINE IF MALFUNCTION CAUSE IS MAGNETIC CLUTCH OR OTHER Start the engine and idle it. Turn the A/C switch on with blower switch is on. Remove the A/C relay. Does the magnetic clutch disengage?	Yes	Go to Step 4.
2		No	Go to the next step.
3	INSPECT IF MALFUNCTION CAUSE IS MAGNETIC CLUTCH POWER SUPPLY OR MAGNETIC CLUTCH Switch the ignition to ON. Remove the A/C relay. Disconnect the magnetic clutch connector. Switch the ignition to ON. Measure the voltage between magnetic clutch terminal A and body ground. Is the voltage B+ ?	Yes	Repair or replace suspected wiring harness and connector.
3		No	Replace the A/C compressor. (Magnetic clutch engagement is stuck.) (See A/C COMPRESSOR REMOVAL/INSTALLATION .)
4	INSPECT A/C RELAY Inspect the A/C relay. (See RELAY INSPECTION .) Is the A/C relay normal?	Yes	Go to the next step.
4		No	Replace the A/C relay.
5	DETERMINE IF MALFUNCTION CAUSE IS A/C REQUEST SIGNAL OR MAGNETIC CLUTCH CONTROL CIRCUIT Access and monitor the PCM PID ACCS using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZR 2.5] .) Start the engine and idle it. Turn the A/C switch on and off with blower switch is on. Is the PID value always ON?	Yes	Full-auto air conditioner: Replace the climate control unit (A/C switch signal is always on). (See CLIMATE CONTROL UNIT REMOVAL/INSTALLATION [FULL-AUTO AIR CONDITIONER] .) Manual air conditioner: Go to the next step.
5		No	Inspect for short to ground between PCM terminal 1I and A/C relay. Repair or replace suspected wiring harness and connector.
6	DETERMINE IF MALFUNCTION CAUSE IS A/C REQUEST SIGNAL RELATED WIRING HARNESS OR CLIMATE CONTROL UNIT (MANUAL AIR CONDITIONER) Switch the ignition to off. Disconnect the instrument cluster and climate control unit connectors. Verify continuity between climate control unit connector terminal 1L and body ground. Is there continuity?	Yes	Repair or replace suspected wiring harness and connector.
6		No	Replace the climate control unit. (A/C switch signal is always on.) (See CLIMATE CONTROL UNIT REMOVAL/INSTALLATION [MANUAL AIR CONDITIONER] .)
7	Verify test results. If normal, return to diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [MZR 2.5] .) 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, reprogram the PCM if a later calibration is available. Retest.

STEP	INSPECTION	RESULTS	ACTION
1	VERIFY A/C SYSTEM OPERATION Does the magnetic clutch disengage when the A/C switch is turned off?	Yes	Go to the next step.
1		No	Go to the symptom troubleshooting "NO.24 A/C IS ALWAYS ON OR A/C COMPRESSOR RUNS CONTINUOUSLY". (See NO.24 A/C IS ALWAYS ON OR A/C COMPRESSOR RUNS CONTINUOUSLY [MZR 2.5] .)
2	VERIFY PCM DTC Retrieve any DTCs using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZR 2.5] .) Are there any DTCs displayed?	Yes	Go to the appropriate DTC inspection. (See DTC TABLE [MZR 2.5] .)
2		No	Inspect the APP sensor. (See ACCELERATOR PEDAL POSITION (APP) SENSOR INSPECTION [MZR 2.5] .) Repair or replace the malfunctioning part according to the inspection results.
3	Verify test results. If normal, return to diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [MZR 2.5] .) 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, reprogram the PCM if a later calibration is available. Retest.

STEP	INSPECTION	RESULTS	ACTION
1	VERIFY IF THERE IS DRIVEABILITY MALFUNCTION OR EXHAUST GAS MALFUNCTION Are any drivability or exhaust smoke concerns present?	Yes	Go to the appropriate symptom troubleshooting.
1		No	Go to the next step.
2	INSPECT RELATED PART CONDITION Inspect the following: Electrical connections Vacuum lines Fuel quality Are all items normal?	Yes	Go to the next step.
2		No	Repair or replace the malfunctioning part according to the inspection results. Repeat Step 2.
3	VERIFY PCM DTC Retrieve any DTCs using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZR 2.5] .) Are there any DTCs displayed?	Yes	Go to the appropriate DTC inspection. (See DTC TABLE [MZR 2.5] .)
3		No	Go to the next step.
4	INSPECT FUEL LINE PRESSURE Inspect the fuel line pressure. (See FUEL LINE PRESSURE INSPECTION [MZR 2.5] .) Is the fuel line pressure correct?	Yes	Go to the next step.
4		No	Zero or low: Inspect the following: Fuel pump relay Fuel pump circuit Fuel line for clogging If there is no malfunction, replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [MZR 2.5] .) High: Replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [MZR 2.5] .)
5	DETERMINE IF MALFUNCTION CAUSE IS CHARCOAL CANISTER OR FUEL TANK VENT SYSTEM Inspect the charcoal canister for fuel saturation. Is an excess amount of liquid fuel present in the canister?	Yes	Replace the charcoal canister. (See CHARCOAL CANISTER, CANISTER VENT (CV) SOLENOID VALVE, AIR FILTER COMPONENT REMOVAL/INSTALLATION [MZR 2.5] .)
5		No	Inspect the fuel tank vent system. Repair or replace the malfunctioning part according to the inspection results. If the fuel tank vent system is normal, suggest trying a different brand since the sulfur content can vary in different fuels.
6	Verify test results. If normal, return to diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [MZR 2.5] .) 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, reprogram the PCM if a later calibration is available. Retest.

STEP	INSPECTION	RESULTS	ACTION
1	VERIFY PCM DTC Retrieve any DTCs using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZR 2.5] .) Are there any DTCs displayed?	Yes	Go to the appropriate DTC inspection. (See DTC TABLE [MZR 2.5] .)
1		No	Go to the next step.
2	DETERMINE IF MALFUNCTION CAUSE IS NONRETURN VALVE OR OTHER Remove the fuel-filler pipe. Make sure nonreturn valve is installed properly. Inspect the nonreturn valve operation. Is the nonreturn valve normal?	Yes	Inspect for the following: Improper use of fuel nozzle Inadequate fuel filling speed Repair or replace the malfunctioning part according to the inspection results.
2		No	Nonreturn valve is installed improperly: Reinstall the nonreturn valve to proper position. Nonreturn valve does not operate properly: Replace the nonreturn valve.
3	Verify test results. If normal, return to diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [MZR 2.5] .) 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, reprogram the PCM if a later calibration is available. Retest.

STEP	INSPECTION	RESULTS	ACTION
1	VERIFY PCM DTC Retrieve any DTCs using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZR 2.5] .) Are there any DTCs displayed?	Yes	Go to the appropriate DTC inspection. (See DTC TABLE [MZR 2.5] .)
1		No	Go to the next step.
2	DETERMINE IF MALFUNCTION CAUSE IS NONRETURN VALVE OR OTHER Remove the fuel-filler pipe. Make sure nonreturn valve is installed properly. Inspect the nonreturn valve operation. Is the nonreturn valve normal?	Yes	Inspect for the following: Improper use of fuel nozzle Fuel is not inserted correctly. Fuel shut-off valve Repair or replace the malfunctioning part according to the inspection results.
2		No	Nonreturn valve is installed improperly: Reinstall the nonreturn valve to proper position. Nonreturn valve does not operate properly: Replace the nonreturn valve.
3	Verify test results. If normal, return to diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [MZR 2.5] .) 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, reprogram the PCM if a later calibration is available. Retest.

STEP	INSPECTION	RESULTS	ACTION
1	VERIFY SPARK PLUG CONDITION Remove all the spark plugs. (See SPARK PLUG REMOVAL/INSTALLATION [MZR 2.5] .) Inspect the spark plug condition. (See SPARK PLUG INSPECTION [MZR 2.5] .) Are the spark plugs conditions normal?	Yes	Symptom troubleshooting completed.
1		No	Specific plug is wet or covered with carbon: Go to the next step. Specific plug looks grayish white: Go to Step 7. All plugs are wet or covered with carbon: Go to Step 9. All plugs look grayish white: Go to Step 15.
2	DETERMINE IF MALFUNCTION CAUSE IS ENGINE OIL LOSS OR OTHER Are the spark plugs wet/covered with carbon from the engine oil?	Yes	Inspect all areas related to oil, working up and down.
2		No	Go to the next step.
3	INSPECT SPARK PLUG Inspect the spark plugs for the following: Cracked insulator Heat range Air gap Worn electrode Are the spark plugs normal?	Yes	Go to the next step.
3		No	Replace the spark plug. (See SPARK PLUG REMOVAL/INSTALLATION [MZR 2.5] .)
4	INSPECT ENGINE COMPRESSION Inspect the compression pressure at the suspected malfunctioning cylinder. (See COMPRESSION INSPECTION [MZR 2.5] .) Is the compression pressure correct?	Yes	Go to the next step.
4		No	Repair or replace the malfunctioning part according to the inspection results.
5	INSPECT IGNITION SYSTEM OPERATION Install all the spark plugs. (See SPARK PLUG REMOVAL/INSTALLATION [MZR 2.5] .) Perform the spark test at the suspected malfunctioning cylinder. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZR 2.5] .) Is a strong blue spark visible? (Compare with normal cylinder.)	Yes	Go to the next step.
5		No	Repair or replace the malfunctioning part according to the inspection results.
6	INSPECT FUEL LINE PRESSURE Inspect the fuel line pressure. (See FUEL LINE PRESSURE INSPECTION [MZR 2.5] .) Is the fuel line pressure correct?	Yes	Inspect the fuel injector for the following: Open or short circuit in injector Leakage Injection volume Repair or replace the malfunctioning part according to the inspection results.
6		No	Zero or low: Inspect the following: Fuel pump relay Fuel pump circuit Fuel line for clogging If there is no malfunction, replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [MZR 2.5] .) High: Replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [MZR 2.5] .)
7	INSPECT SPARK PLUG Inspect the spark plug for the following: Heat range Air gap Is the spark plug normal?	Yes	Go to the next step.
7		No	Replace the spark plug. (See SPARK PLUG REMOVAL/INSTALLATION [MZR 2.5] .)
8	INSPECT FUEL INJECTOR OPERATION Perform the Fuel Injector Operation Inspection. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZR 2.5] .) Do the fuel injectors operate properly?	Yes	Go to the next step.
8		No	Repair or replace the malfunctioning part according to the inspection results.
9	INSPECT AIR CLEANER ELEMENT Is the air cleaner element free of clogging?	Yes	Go to the next step.
9		No	Replace the air cleaner element.
10	INSPECT IGNITION SYSTEM OPERATION Perform the Spark Test. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZR 2.5] .) Is a strong blue spark visible at each cylinder?	Yes	Go to the next step.
10		No	Repair or replace the malfunctioning part according to the inspection results.
11	INSPECT FUEL LINE PRESSURE Inspect the fuel line pressure. (See FUEL LINE PRESSURE INSPECTION [MZR 2.5] .) Is the fuel line pressure correct?	Yes	Go to the next step.
11		No	Zero or low: Inspect the following: Fuel pump relay Fuel pump circuit Fuel line for clogging If there is no malfunction, replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [MZR 2.5] .) High: Replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [MZR 2.5] .)
12	VERIFY CURRENT INPUT SIGNAL STATUS Access the following PCM PIDs: ECT O2S11 (When engine can be started.) O2S12 (When engine can be started.) MAF Are all PIDs normal? (See PCM INSPECTION [MZR 2.5] .)	Yes	Go to the next step.
12		No	ECT PID is not as specified: Inspect for an intermittent open circuit of the ECT sensor and the related wiring harness. (See ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION [MZR 2.5] .) MAF PID is not as specified: Inspect for an intermittent open circuit of the MAF sensor and the related wiring harness. (See MASS AIR FLOW (MAF) SENSOR INSPECTION [MZR 2.5] .) O2S11 PID is not as specified: Inspect for an intermittent open circuit of the A/F sensor and the related wiring harness. (See AIR FUEL RATIO (A/F) SENSOR INSPECTION [MZR 2.5] .) O2S12 PID is not as specified: Inspect for an intermittent open circuit of the HO2S and the related wiring harness. (See HEATED OXYGEN SENSOR (HO2S) INSPECTION [MZR 2.5] .) Repair or replace the malfunctioning part according to the inspection results.
13	INSPECT PURGE CONTROL SYSTEM OPERATION Perform the purge control inspection. (When engine can be started.) (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZR 2.5] .) Is the purge control correct?	Yes	Go to the next step.
13		No	Repair or replace the malfunctioning part according to the inspection results.
14	INSPECT ENGINE COMPRESSION Perform the compression inspection. (See COMPRESSION INSPECTION [MZR 2.5] .) Is the compression correct?	Yes	Visually inspect for deformed exhaust system parts. Repair or replace the malfunctioning part according to the inspection results.
14		No	Repair or replace the malfunctioning part according to the inspection results.
15	INSPECT INTAKE-AIR SYSTEM FOR AIR SUCTION Inspect the following: Intake air system for air leakage (When the engine cannot be started.) Intake manifold vacuum (When the engine can be started.) Is air sucked in from intake air system?	Yes	Repair or replace the malfunctioning part according to the inspection results.
15		No	Go to the next step.
16	INSPECT FUEL LINE PRESSURE Inspect the fuel line pressure. (See FUEL LINE PRESSURE INSPECTION [MZR 2.5] .) Is the fuel line pressure correct?	Yes	Go to the next step.
16		No	Zero or low: Inspect the following: Fuel pump relay Fuel pump circuit Fuel line for clogging If there is no malfunction, replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [MZR 2.5] .) High: Replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [MZR 2.5] .)
17	VERIFY CURRENT INPUT SIGNAL STATUS Access the following PCM PIDs: ECT O2S11 (When engine can be started.) O2S12 (When engine can be started.) MAF Are all PIDs normal? (See PCM INSPECTION [MZR 2.5] .)	Yes	Inspect the PCM ground condition. Repair or replace the malfunctioning part according to the inspection results.
17		No	ECT PID is not as specified: Inspect for an intermittent open circuit of the ECT sensor and the related wiring harness. (See ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION [MZR 2.5] .) MAF PID is not as specified: Inspect for an intermittent open circuit of the MAF sensor and the related wiring harness. (See MASS AIR FLOW (MAF) SENSOR INSPECTION [MZR 2.5] .) O2S11 PID is not as specified: Inspect for an intermittent open circuit of the A/F sensor and the related wiring harness. (See AIR FUEL RATIO (A/F) SENSOR INSPECTION [MZR 2.5] .) O2S12 PID is not as specified: Inspect for an intermittent open circuit of the HO2S and the related wiring harness. (See HEATED OXYGEN SENSOR (HO2S) INSPECTION [MZR 2.5] .) Repair or replace the malfunctioning part according to the inspection results.
18	Verify test results. If normal, return to diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [MZR 2.5] .) 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, reprogram the PCM if a later calibration is available. Retest.

Inspection Method for Sensors

Connect the M-MDS to the DLC-2.
Switch the ignition to ON (engine off). NOTE: If the engine starts and runs, perform the following steps during idle.
Access PIDs for the switch you are inspecting.
Vibrate the sensor slightly with your finger. If PID value is unstable or malfunction occurs, check for poor connection or poorly mounted sensor or both.

Scheme 58

Scheme 58: Inspection Method for Actuators or Relays

Connect the M-MDS to the DLC-2.
Switch the ignition to ON (engine off). NOTE: If the engine starts and runs, perform the following steps during idle.
Prepare the output state control function for actuators or relays that you are inspecting.
Vibrate the actuator or relay with your finger for 3 s after output state control function is activated. If variable click sound is heard, check for poor connection or poorly mounted actuator or both, or the relay. NOTE: Vibrating relays too strongly may result in open relays.

Input Signal System Inspection Procedure

Find an irregular signal. (See «FINDING IRREGULAR SIGNALS»(ref-581642-S40416106512013101400000) .)
Locate source. (See «LOCATING THE SOURCE OF UNUSUAL SIGNALS»(ref-581642-S28532199592013101400000) .)
Repair or replace the malfunctioning part.
Confirm that the irregular signal is no longer detected.

Input signal system inspection for thermistor type

When an irregular signal is detected, measure the #1 PCM terminal voltage. If the #1 terminal voltage and the M-MDS monitor voltage are the same, proceed to the next step. If there is a difference of 0.5 V or more , inspect the following points concerning the PCM connector: Female terminal opening loose Coupler (pin holder) damage Pin discoloration (blackness) Harness/pin crimp is loose or disconnected.
Measure the #2 sensor terminal voltage. If there is a 0.5 V or more difference between the sensor and the M-MDS voltages, inspect the wiring harness for open or short circuits. If the sensor and the M-MDS voltages are the same, inspect the following points concerning the sensor connector: Female terminal opening is loose. Coupler (pin holder) damage Pin discoloration (blackness) Harness/pin crimp is loose or disconnected. If there are no problems, proceed to next investigation below.

GND system inspection for thermistor type

Confirm that terminal sensor #3 is at 0 V . If it is at 0 V , inspect the sensor. If necessary, replace the sensor. If not, inspect for the following: Open circuit in wiring harness Female terminal opening is loose. Coupler (pin holder) damage Pin discoloration (blackness) Harness/pin crimp is loose or disconnected.

Intake Manifold Vacuum Inspection

Verify air intake hoses are installed properly.
Start the engine and run it at idle.
Disconnect the vacuum hose between the intake manifold and purge solenoid valve from the intake manifold side.
Connect a vacuum gauge to the intake manifold and measure the intake manifold vacuum. If not as specified, inspect the following: Specification More than 60 kPa {450 mmHg, 18 inHg} NOTE: Air suction can be located by engine speed change when lubricant is sprayed on the area where suction is occurring. Air suction at throttle body, intake manifold and PCV valve installation points EGR valve (stuck open) Fuel injector insulator Engine compression (See «COMPRESSION INSPECTION [MZR 2.5]»(ref-581643-S19165968822013101400000) .)

Engine coolant temperature compensation inspection

Connect the M-MDS to the DLC-2.
Access the following PCM PIDs: (See «ON-BOARD DIAGNOSTIC TEST [MZR 2.5]»(ref-581633-S34331335932013101400000) .) ECT IAT RPM
Verify that the engine is cold, then start the engine.
Verify that the engine speed decreases as the engine warms up. If the engine speed does not decrease or decreases slowly, inspect the following: ECT sensor and related wiring harness (See «ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION [MZR 2.5]»(ref-581641-S34631696002013101400000) .) Throttle body and related wiring harness (See «THROTTLE BODY INSPECTION [MZR 2.5]»(ref-581645-S19408073302013101400000) .)

Load compensation inspection

Start the engine and idle it.
Connect the M-MDS to the DLC-2.
Verify that P0506:00 or P0507:00 is not displayed. (See «ON-BOARD DIAGNOSTIC TEST [MZR 2.5]»(ref-581633-S34331335932013101400000) .) If the P0506:00 or P0507:00 are displayed, perform DTC inspection. (See «DTC P0506:00 [MZR 2.5]»(ref-581633-S22968963292013101400000) .) (See «DTC P0507:00 [MZR 2.5]»(ref-581633-S39288482662013101400000) .)
Access the PCM PID RPM. (See «ON-BOARD DIAGNOSTIC TEST [MZR 2.5]»(ref-581633-S34331335932013101400000) .) NOTE: Excludes temporary idle speed drop just after the loads are turned on.
Verify that the engine speed is within the specification under each load condition. If load condition is not as specified, inspect the following: A/C switch and related wiring harness (See «CLIMATE CONTROL UNIT INSPECTION [MANUAL AIR CONDITIONER]»(ref-581664-S00686458732013101400000) .) (See «CLIMATE CONTROL UNIT INSPECTION [FULL-AUTO AIR CONDITIONER]»(ref-581663-S40376799252013101400000) .) Fan switch and related wiring harness (See «CLIMATE CONTROL UNIT INSPECTION [MANUAL AIR CONDITIONER]»(ref-581664-S00686458732013101400000) .) (See «CLIMATE CONTROL UNIT INSPECTION [FULL-AUTO AIR CONDITIONER]»(ref-581663-S40376799252013101400000) .) PSP switch and related wiring harness (See «POWER STEERING PRESSURE (PSP) SWITCH INSPECTION [MZR 2.5]»(ref-581641-S14099109302013101400000) .) Idle speed (ATX: P, N position, MTX: Neutral position) 600-700 rpm Idle-up speed (ATX: P, N position, MTX: Neutral position) A/C on and: 600-850 rpm Electrical loads on: 650-750 rpm (MTX), 600-750 rpm (ATX) While turning steering wheel: 650-750 rpm

Throttle position (TP) sweep inspection

Connect the M-MDS to the DLC-2.
Switch the ignition to ON.
Verify that none of the following DTC are displayed: (See «ON-BOARD DIAGNOSTIC TEST [MZR 2.5]»(ref-581633-S34331335932013101400000) .) P0122:00, P0123:00, P0222:00, P0223:00, P0638:00, P2100:00, P2101:00, P2107:00, P2108:00, P2119:00, P2122:00, P2123:00, P2127:00, P2128:00, P2135:00, P2138:00 If any one DTC is displayed, perform DTC inspection. (See «DTC TABLE [MZR 2.5]»(ref-581633-S19834179122013101400000) .)
Access the PCM PIDs APP1 and APP2 using the M-MDS. (See «ON-BOARD DIAGNOSTIC TEST [MZR 2.5]»(ref-581633-S34331335932013101400000) .)
Verify the APP1 and APP2 PIDs when the accelerator pedal released and depresses.

Fuel Cut Control System Inspection

Warm up engine and idle it.
Turn off the electrical loads and A/C switch.
Connect the M-MDS to the DLC-2.
Access the PCM PID RPM. (See «ON-BOARD DIAGNOSTIC TEST [MZR 2.5]»(ref-581633-S34331335932013101400000) .)
Listen for the fuel injector operation sound at all cylinders using the soundscope and monitor both PIDs while performing the following steps: Depress the accelerator pedal and increase the engine speed to 4,000 rpm . Quickly release the accelerator pedal (brake pedal is not depressed) and verify that the fuel injector operation sound stops, and starts again when the engine speed drops below 1,200 rpm . If not as specified, inspect the following: ECT sensor and related wiring harness (See «ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION [MZR 2.5]»(ref-581641-S34631696002013101400000) .) CPP switch and related wiring harness (MTX) (See «CLUTCH PEDAL POSITION (CPP) SWITCH INSPECTION [MZR 2.5]»(ref-581641-S07778649072013101400000) .) Neutral switch and related wiring harness (MTX) (See «NEUTRAL SWITCH INSPECTION [MZR 2.5]»(ref-581641-S12392617192013101400000) .) TR switch and related wiring harness (ATX) (See «TRANSAXLE RANGE (TR) SWITCH INSPECTION [FS5A-EL]»(ref-581660-S00019717112013101400000) .)

Fuel Pump Control System Inspection

Crank the engine and verify that fuel pump relay operation sound is heard.
If operation sound is not heard, inspect the following: Fuel pump relay (See «RELAY INSPECTION»(ref-581640-S26749992412013101400000) .) Wiring harness and connectors (Main relay-Fuel pump relay-PCM terminal 1BG)

Spark Test

Disconnect the fuel pump relay.
Verify that each ignition coil and connector is connected properly.
Inspect the ignition system in the following procedure. WARNING: High voltage in the ignition system can cause strong electrical shock which can result in serious injury. Avoid direct contact to the vehicle body during the following spark test.

STEP	INSPECTION		ACTION
1	Disconnect the ignition coil from the spark plugs. Remove the spark plugs. (See SPARK PLUG REMOVAL/INSTALLATION [MZR 2.5] .) Verify that the spark plugs do not have carbon deposits. Are the spark plugs normal?	Yes	Go to the next step.
1		No	Perform no-load racing at 4,000 rpm for 2 min , 2 times to burn off the carbon deposits. Repeat Step 1.
2	Inspect the spark plugs for damage, wear, and proper plug gap. Are the spark plugs normal?	Yes	Go to the next step.
2		No	Replace the spark plugs, then go to Step 1. (See SPARK PLUG REMOVAL/INSTALLATION [MZR 2.5] .)
3	Reconnect the spark plugs to the ignition coil. Ground the spark plugs to the engine. Is a strong blue spark visible at each cylinder while cranking the engine?	Yes	Ignition system is normal.
3		No	Some cylinders do not spark: Go to the next step. All cylinders do not spark: Go to Step 5.
4	Inspect the following wiring harnesses for open or short: Ignition coil No.1 terminal C-PCM terminal 2G Ignition coil No.2 terminal C-PCM terminal 2K Ignition coil No.3 terminal C-PCM terminal 2L Ignition coil No.4 terminal C-PCM terminal 2H Are the wiring harnesses normal?	Yes	Inspect the ignition coil. (See IGNITION COIL INSPECTION [MZR 2.5] .) Repair or replace the malfunctioning part according to the inspection results.
4		No	Repair or replace suspected wiring harness and connector, then go to Step 1.
5	Switch the ignition to ON (engine off). Measure the voltage at terminal A in each ignition coils. Is the voltage B+ ?	Yes	Go to the next step.
5		No	Inspect the power supply circuit of ignition coils. Repair or replace suspected wiring harness and connector.
6	Switch the ignition to off. Disconnect the ignition switch connector. Inspect for continuity between each ignition coil terminal B and body ground. Is there continuity?	Yes	Go to the next step.
6		No	Repair or replace suspected wiring harness and connector.
7	Does the PCM connector or ignition coil connectors have a poor connection?	Yes	Repair or replace the connector, then go to Step 1.
7		No	Go to the next step.
8	Are the CKP sensor and crankshaft pulley normal?	Yes	Inspect for an open or short circuit in the wiring harness and connector of CKP sensor. Repair or replace suspected wiring harness and connector.
8	Are the CKP sensor and crankshaft pulley normal?	No	Repair or replace the malfunctioning part according to the inspection results.

EGR Control System Inspection

Crank the engine and verify that EGR valve operation (initial operation) sound is heard. If the operation sound is not heard, connect the M-MDS to the DLC-2 and verify that the DTC P0403:00 is shown. (See «ON-BOARD DIAGNOSTIC TEST [MZR 2.5]»(ref-581633-S34331335932013101400000) .) Perform DTC inspection. (See «DTC P0403:00 [MZR 2.5]»(ref-581633-S36913384562013101400000) .)
Start the engine and idle it.
Warm up the engine to normal operating temperature.
Access the following PCM PIDs: (See «ON-BOARD DIAGNOSTIC TEST [MZR 2.5]»(ref-581633-S34331335932013101400000) .) ECT, RPM, SEGRP_DSD, APP1, APP2, VSS
Idle the vehicle and verify that the SEGRP value is 0. CAUTION: While performing this step, always operate the vehicle in a safe and lawful manner. When the M-MDS is used to observe monitor system status while driving, be sure to have another technician with you, or record the data in the M-MDS using the PID/DATA MONITOR AND RECORD capturing function and inspect later.
Put the vehicle in drive.
Depress the accelerator pedal and verify that the SEGRP_DSD value is increased. If the EGR valve increases, inspect the following: EGR valve (stuck open or close) (See «EGR VALVE INSPECTION [MZR 2.5]»(ref-581647-S05349658702013101400000) .) Wiring harness and connectors (Main relay-EGR valve-PCM) If the SEGRP_DSD value does not increase, inspect the VSS, APP1, APP2, TP REL and ECT PIDs. (See «PCM INSPECTION [MZR 2.5]»(ref-581641-S02967527962013101400000) .)
Stop the vehicle and verify that the SEGRP value returns to 0.

Purge Control System Inspection

If simulation function of M-MDS is used

Start the engine.
Disconnect the vacuum hose between the purge solenoid valve and the charcoal canister.
Put a finger to the purge solenoid valve and verify that there is no vacuum applied when the engine is cold. If there is a vacuum, inspect the following: Wiring harness and connectors (Purge solenoid valve-PCM terminal 2C) Purge solenoid valve (stuck open) (See «PURGE SOLENOID VALVE INSPECTION [MZR 2.5]»(ref-581647-S31009304002013101400000) .)
Verify that the DTC P0443:00 is displayed. (See «ON-BOARD DIAGNOSTIC TEST [MZR 2.5]»(ref-581633-S34331335932013101400000) .) If the DTC P0443:00 is shown, perform the DTC inspection. (See «DTC P0443:00 [MZR 2.5]»(ref-581633-S42314288292013101400000) .)
Access the PCM PID EVAPCP using the M-MDS. (See «ON-BOARD DIAGNOSTIC TEST [MZR 2.5]»(ref-581633-S34331335932013101400000) .)
Put a finger to the purge solenoid valve with Step 2 condition and verify that there is vacuum applied when set the present to 100 % duty value of the purge solenoid valve using the EVAPCP PID simulation function. If there is no vacuum, inspect the following: Increase the duty value of the purge solenoid valve to 50 % and inspect if the operation sound of the valve is heard. If the operation sound is heard, inspect for loose or damaged vacuum hoses. (Intake manifold-Purge solenoid valve-Charcoal canister) If the operation sound is not heard, inspect the purge solenoid valve. (See «PURGE SOLENOID VALVE INSPECTION [MZR 2.5]»(ref-581647-S31009304002013101400000) .)
Warm up the engine to normal operating temperature.
Monitor the EVAPCP PID using the M-MDS, and drive the vehicle approx. 2000 rpm for 30 s or more . If the EVAPCP PID is 0 %, inspect the following: MAF, APP1, APP2, TP REL and LOAD PIDs (See «PCM INSPECTION [MZR 2.5]»(ref-581641-S02967527962013101400000) .)

If simulation function of M-MDS is not used

Start the engine.
Disconnect the vacuum hose between the purge solenoid valve and the charcoal canister.
Put a finger to the purge solenoid valve and verify that there is no vacuum applied when the engine is cold. If there is a vacuum, inspect the following: Wiring harness and connectors (Purge solenoid valve-PCM terminal 2C) Purge solenoid valve (See «PURGE SOLENOID VALVE INSPECTION [MZR 2.5]»(ref-581647-S31009304002013101400000) .)
Warm up the engine to the normal operating temperature.
Stop the engine.
Verify that the DTC P0443:00 is displayed. (See «ON-BOARD DIAGNOSTIC TEST [MZR 2.5]»(ref-581633-S34331335932013101400000) .) If the DTC P0443:00 is shown, perform the DTC inspection. (See «DTC P0443:00 [MZR 2.5]»(ref-581633-S42314288292013101400000) .)
Switch the ignition to ON.
Access the PCM PID ECT. (See «ON-BOARD DIAGNOSTIC TEST [MZR 2.5]»(ref-581633-S34331335932013101400000) .)
Verify that the engine coolant temperature is more than 78 °C {172 °F} . If the M-MDS indicates less than 78 °C {172 °F} , perform the ECT sensor inspection. (See «ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION [MZR 2.5]»(ref-581641-S34631696002013101400000) .)
Set the vehicle on the dynamometer or chassis roller. WARNING: When the dynamometer or chassis roller is operating, there is a possibility that the operator may come into contact with or be caught up in the rotating parts, leading to serious injuries or death. When performing work while the dynamometer or chassis roller is operating, be careful not to come into contact with or be caught up in any of the rotating parts.
Drive vehicle at engine speed approx. 2,000 rpm for 30 s or more.
Put a finger to the purge solenoid valve and verify that there is no vacuum applied while step 2 . If there is no vacuum, inspect the following: Wiring harness and connector (Main relay-Purge solenoid valve-PCM terminal 2C) Purge solenoid valve (See «PURGE SOLENOID VALVE INSPECTION [MZR 2.5]»(ref-581647-S31009304002013101400000) .) MAF, APP1, APP2, TP REL and LOAD PIDs (See «PCM INSPECTION [MZR 2.5]»(ref-581641-S02967527962013101400000) .) If there is vacuum, inspect the following: Vacuum hose (Purge solenoid valve-Charcoal canister)

A/C Cut-Off Control System Inspection

Start the engine.
Turn the A/C switch and the fan switch on.
Verify that the magnetic clutch actuates. If it does not actuate, go to symptom troubleshooting "NO.23 A/C DOES NOT WORK SUFFICIENTLY". (See «NO.23 A/C DOES NOT WORK SUFFICIENTLY [MZR 2.5]»(ref-581642-S31765901512013101400000) .)
Fully open the throttle valve and verify that the magnetic clutch does not actuate for 2-5 s . If it actuates, inspect as follows: A/C relay (See «RELAY INSPECTION»(ref-581640-S26749992412013101400000) .) Open or short to ground circuit in wiring harness and connectors (Ignition switch (IG2) (without advanced keyless entry and push button start system)/IG2 relay (with advance keyless entry and push button start)-A/C relay-PCM terminal 1I) A/C related parts APP1, APP2 PIDs (See «PCM INSPECTION [MZR 2.5]»(ref-581641-S02967527962013101400000) .)

Cooling Fan Control System Inspection

Connect the M-MDS to the DLC-2.
Start the engine and warm it up to normal operating temperature.
Perform the KOER self-test. (See «KOEO/KOER SELF TEST [MZR 2.5]»(ref-581633-S11361132362013101400000) .)
Verify that the DTC P0480:00 is not shown and the cooling fan operates during the KOER self-test. If DTC P0480:00 is shown, perform the DTC inspection. (See «DTC P0480:00 [MZR 2.5]»(ref-581633-S35755573672013101400000) .) If the cooling fans do not operate, indicated order in accordance with fan operation conditions.

Evaporative Emission (EVAP) System Leak Inspection

To verify that the problem has been fixed properly after repairs, the run drive cycle or EVAP system leak inspection must be performed.

EVAP system leak inspection using the M-MDS

EVAP system test out line

The EVAP system test, which can substituted for the run drive cycle as an EVAP control system repair confirmation method, can detect the small/large leak or blockage without run-drive cycle.

Note. M-MDS can not detect "VERY SMALL LEAK". To identify the leak point, please use the leak tester or ultrasonic leak detector. EVAP system test description The EVAP system test finds gas leaks or blockage of EVAP system using the changes of the fuel tank pressure. This test starts after sending an on-demand test signal from the M-MDS to the PCM. This test consists of three stages, and each stage is performed automatically as follows: Stage 1 test (Test for large leak or blockage) M-MDS send the stage 1 test start signal to the PCM. PCM controls the CV solenoid valve and purge solenoid valve to control the tank pressure to the targeted value. M-MDS detect the large leak or the purge line blockage if the tank pressure does not arrive at the target vacuum in specified period. Stage 2 test (Test for small leak) When fuel tank pressure arrived at the targeted pressure at stage 1 test, M-MDS send the stage 2 test signal to the PCM to turn off the purge solenoid to keep the tank pressure. M-MDS detect the small leak if the tank pressure can not keep within the target in specified period. Stage 3 test (Test for blockage) M-MDS send the stage 3 test signal to the PCM to turn off the CV solenoid for check the blockage of EVAP system. M-MDS detect blockage of the CV solenoid valve or air filter if the tank pressure does not arrive at the target (atmosphere).

Scheme 59

Scheme 59: EVAP System Malfunction Judgment

Scheme 60

M-MDS detect the small/large leak or blockage based on fuel tank pressure at the end of EVAP Test. A small leak in the purge solenoid valve is suspect.
This judgment means tank pressure goes to minus side at stage 2 test. Check the purge solenoid valve. Refer to the workshop manual. Evaporative system test procedure
Verify that all PIDs within the following specifications. NOTE: To successfully perform this procedure, all PIDs must be within the specifications before proceeding to the next step.
Select the following items from the initialization screen of the M-MDS. Select the "Powertrain". Select the "Fuel". Select the "EVAP Test". Verify that ECT and IAT are within the specifications at the confirmation screen. To successfully perform this procedure, ECT and IAT must be within the spec before proceeding to the next step. Fuel Level must be maintained within 15 %-85 % . PCM will cancel the EVAP Test If the Fuel Level is lower than 15 % or higher than 85 % .
Verify the test results described on the M-MDS and follow the instructions.

Scheme 61

Scheme 61: EVAP system leak inspection using leak tester

Scheme 62

Perform the following SST (EVAP System Tester 134-01049A) self-test: NOTE: If the tester does not work correctly during the self-test, refer to the tester operators manual for a more detailed self-test procedure. Verify that the control valve on the panel is in the HOLD position then open the nitrogen bottle valve. Connect the vehicle interface hose (part of the SST ) to the SELF-TEST port located on the control panel. Hand tighten the fitting. (Do not overtighten.) Turn the control valve to the TEST position. The gauge should read 331-381 mm {13.1-15.0 in} of water. If the gauge is not reading in this range, adjust the pressure by turning the black knob on the low pressure regulator at the nitrogen bottle. Turn the control valve to the HOLD position. Verify that the gauge holds pressure and that the flow meter reads no flow. If there is no drop in pressure and no flow, the tester passes the self-test. If the gauge leaks down, refer to the tester operators manual.
Connect the SST to the vehicle. Verify that the control valve on the panel is in the HOLD position then open the nitrogen bottle valve. Remove the fuel-filler cap from the vehicle. If the fuel-filler cap is not a MAZDA part or equivalent, replace it. NOTE: INSPECT FUEL FILLER CAP AND FILLER NECK Visually inspect for damage, insufficient sealing, rust, cracks or warps for filler cap and filler neck. Repair or replace if necessary. Connect the receiver assembly ( SST : 134-01059) to the vehicle cap test hose assembly (part of the SST ) and the fuel-filler cap from the vehicle. Connect the cap adaptor ( SST : 134-01058) to the vehicle cap test hose assembly (part of the SST ) and to the fuel-filler neck. Connect the vehicle interface hose (part of the SST ) to the center fitting of the vehicle cap test hose assembly (part of the SST ).
Connect the M-MDS to the DLC-2.
Switch the ignition to ON (engine off).
Request the PCM on-board device control (Mode 08) using the M-MDS to close the canister vent value. NOTE: The canister vent value is closed for 10 min unless the following any actions are done: The engine is started. The ignition switch is turned off position.
Make sure the control valve on the 134-01049A is in the HOLD position and that the valve on the cylinder of nitrogen gas is open.
Turn the control valve to the open position and let the system fill. You should note a drop in the gauge pressure along with the flow meter being pegged at maximum flow for several minutes depending on how full or empty the fuel tank is, and how long it takes to completely fill and pressurize the EVAP system hoses.
If the gauge and the flow meter do not settle to a measurable level after 2 - 3 min , then refer to the Mazda Workshop Manual to verify that the canister vent valve is properly closed. If canister vent valve is properly closed. The EVAP system has large leakage. Check for leakage and repair as necessary.
Verify the pressure gauge and flow meter reading to determine if there is an EVAP leak: NO EVAPORATIVE LEAK: The flow meter registers "zero flow" and the pressure gauge returns to the pre-set pressure of 356 mm {14.0 in} of water (H2O). EVAPORATIVE LEAK: The pressure does not return to the preset level of 356 mm {14.0 in} of water (H2O) when measuring the flow. See "SETTING LEAK STANDARD FOR TESTING" (.020 to.040 inch H2O) of the Evaporative Emissions Tester operators manual (134-01067). NOTE: Turn the control valve to the HOLD position then disconnect the SST .

Symptom Troubleshooting [Engine Control System [Mzr 2.5]]: Diagnosis Mazda 6 GJ

SYMPTOM DIAGNOSTIC INDEX [MZR 2.5]

Diagnostic Index

Scheme 51

Scheme 52

Scheme 53

Scheme 54

Scheme 55

Scheme 56

Scheme 57

Diagnostic Procedure

Inspection Method for Sensors

Scheme 58

Input Signal System Inspection Procedure

Input signal system inspection for thermistor type

GND system inspection for thermistor type

Intake Manifold Vacuum Inspection

Engine coolant temperature compensation inspection

Load compensation inspection

Throttle position (TP) sweep inspection

Fuel Cut Control System Inspection

Fuel Pump Control System Inspection

Spark Test

EGR Control System Inspection

Purge Control System Inspection

A/C Cut-Off Control System Inspection

Cooling Fan Control System Inspection

Evaporative Emission (EVAP) System Leak Inspection

EVAP system leak inspection using the M-MDS

Scheme 59

Scheme 60

Scheme 61

Scheme 62

More articles — Symptom Troubleshooting [Engine Control System [Mzr 2.5]]

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