Engine Controls - System & Component Testing: Other Mazda 6 GG

VARIABLE AIR DUCT SYSTEM - MAZDA6

Note. For Variable Air Duct (VAD) system component locations, see appropriate vacuum diagram in VACUUM DIAGRAMS article.

VARIABLE INERTIA CHARGE SYSTEM - PROTEGE & PROTEGE5

Note. For Variable Inertia Charge System (VICS) component locations, see appropriate vacuum diagram in VACUUM DIAGRAMS article.

Variable Inertia Charge System (VICS) Check Valve (One-Way)

Remove VICS check valve (one-way). Blow air into port "A" and ensure air flows from port "B". (Scheme 138) Blow air into port "B". Air should not flow from port "A". If airflow is not as specified, replace VICS check valve (one-way).

Scheme 138

Variable Tumble Control System (VTCS) Solenoid Check

Remove VTCS solenoid. Check solenoid airflow. Air should flow through ports "B" and "C". (Scheme 139) Apply battery voltage to solenoid. Check airflow. Air should flow through ports "A" and "B". If air flow is not as specified, replace VTCS solenoid. If solenoid is okay, check vacuum lines. Repair as necessary. If problem is not present, Check for open or short circuit. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS. Repair or replace wiring harness as necessary.

Scheme 139

Ground Circuit Checks

1. Using an ohmmeter, check ground circuits to Powertrain Control Module (PCM) for continuity to ground. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS to determine PCM ground terminals. See «PCM LOCATIONS»(ref-151892-S01261515462003010900000) table. If continuity is not present, repair open circuit to ground.
2. Using a voltmeter, touch negative lead to a good ground. Touch positive lead to each ground terminal. With vehicle running, voltmeter should indicate less than one volt. If voltage reading is more than one volt, check for open circuit, corrosion, or loose connection on ground lead.

Power Circuit Checks

1. Using a voltmeter, check for battery voltage between PCM constant battery power terminals and ground. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS to determine PCM power terminals. See «PCM LOCATIONS»(ref-151892-S01261515462003010900000) table. If battery voltage is not present, check PCM power supply fuse. If fuse is okay, check for open in power supply or PCM wiring.
2. Turn ignition on. Using a voltmeter, check for battery voltage between PCM ignition power terminals and ground. If battery voltage is not present, check power supply fuse(s). If fuse is okay, check for an open in wiring between fuse and PCM, or check for a defective ignition switch.
3. Connect voltmeter between ground and PCM start (crank) signal terminal. Turn ignition switch to START position. Battery voltage should be present between PCM start terminal and ground only when ignition switch is in START position. If voltage is not present, check fuse(s). If fuse is okay, check for open circuit in wiring harness between fuse and PCM. If wiring harness is okay, check for a defective ignition switch.

PCM LOCATIONS

MAZDA6 (2.3L)

1. Turn ignition switch to ON position, engine off.
2. Using DVOM, back probe PCM 30-pin harness connector terminal No. 2A and 27-pin harness connector terminal No. 3D. (Scheme 140) Ensure voltage readings change smoothly while throttle valve is gradually opened. If voltage readings change smoothly, go to next step. If voltage readings do not change smoothly, go to step 4.
3. Check PCM 30-pin harness connector terminal No. 2A and 27-pin harness connector terminal No. 3D voltage readings. See «ACCELERATOR PEDAL POSITION SENSOR VOLTAGE SPECIFICATIONS»(ref-151892-S15020882372003050800000) table. If voltage readings are as specified, replace throttle body. If voltage readings are not as specified, go to next step. ACCELERATOR PEDAL POSITION SENSOR VOLTAGE SPECIFICATIONS Accelerator Pedal Position PCM Terminal No. 3D (Volts) PCM Terminal No. 2A (Volts) Released 1.55-1.62 1.01-1.07 Depressed 3.49-4.09 2.94-3.54
4. Backprobe APP sensor 6-pin harness connector. (Scheme 141) Check for short or open circuit. Using DVOM, check continuity between following terminals: Open Circuit APP sensor 6-pin harness connector terminal "A" and PCM 30-pin harness connector terminal No. 2K (Red/Black wire) through common connector. APP sensor 6-pin harness connector terminal "B" and PCM 30-pin harness connector terminal No. 2H (Brown wire) through common connector. APP sensor 6-pin harness connector terminal "C" and PCM 30-pin harness connector terminal No. 2A (Blue/Yellow wire) through common connector. APP sensor 6-pin harness connector terminal "D" and PCM 27-pin harness connector terminal No. 3G (Gray wire). APP sensor 6-pin harness connector terminal "E" and PCM 27-pin harness connector terminal No. 3A (Red/Green wire) through common connector. APP sensor 6-pin harness connector terminal "F" and PCM 27-pin harness connector terminal No. 3D (White wire) through common connector. If continuity is present, go to next step. If continuity is not present, repair open circuit in suspect wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS. Short Circuit APP sensor 6-pin harness connector terminal "A" and power supply (Red/Black wire). APP sensor 6-pin harness connector terminal "A" and body ground (Red/Black wire). APP sensor 6-pin harness connector terminal "B" and power supply (Brown wire). APP sensor 6-pin harness connector terminal "C" and power supply (Blue/Yellow wire). APP sensor 6-pin harness connector terminal "C" and body ground (Blue/Yellow wire). APP sensor 6-pin harness connector terminal "D" and power supply (Gray wire). APP sensor 6-pin harness connector terminal "D" and body ground (Gray wire). APP sensor 6-pin harness connector terminal "E" and power supply (Red/Green wire). APP sensor 6-pin harness connector terminal "F" and power supply (White wire). APP sensor 6-pin harness connector terminal "F" and body ground (White wire). If continuity is present, repair short circuit in suspect wire or replace wire harness. If open or short circuits are not present, accelerator pedal. See «ACCELERATOR PEDAL POSITION SENSOR»(ref-151901-S21728049852003050800000) under ENGINE SENSORS & SWITCHES in REMOVAL OVERHAUL & INSTALLATION article.

Scheme 140

Scheme 141

MAZDA6 (3.0L)

1. Connect scan tool to DLC-2.
2. Turn ignition switch to ON position.
3. Select APP1 or APP2 PID (percentage) on scan tool.
4. Ensure APP1 or APP2 PID (percentage) changes smoothly while accelerator pedal is gradually depressed. If PID value changes as specified, go to next step. If PID value is not as specified, go to step 6.
5. Ensure APP1 or APP2 PID (percentage) is as specified in table according to condition of accelerator pedal. See «ACCELERATOR PEDAL POSITION SENSOR VOLTAGE SPECIFICATIONS»(ref-151892-S30131336772003051200000) table. If PID values are as specified, check for open or short circuit. Go to next step. If PID values are not as specified in table, replace APP sensor. ACCELERATOR PEDAL POSITION SENSOR VOLTAGE SPECIFICATIONS Accelerator Pedal Condition APP1 PID Percentage APP1 PID Voltage APP2 PID Percentage APP2 Voltage Released 31.0-32.4 1.55-1.62 20.2-21.4 1.01-1.07 Depressed 69.8-81.8 3.49-4.09 58.8-70.8 2.94-3.54
6. Open Circuit Inspection Disconnect PCM 104-pin harness connector. (Scheme 142) Back probe APP sensor 6-pin harness connector. (Scheme 141) Check for continuity between following terminals: APP sensor 6-pin harness connector terminal "A" (Red/Black wire) and PCM 104-pin harness connector terminal No. 45 (Light Green/Red wire) through common connector. APP sensor 6-pin harness connector terminal "B" (Brown wire) and PCM 104-pin harness connector terminal No. 11 (Gray/Black wire) through common connector. APP sensor 6-pin harness connector terminal "C" and PCM 104-pin harness connector terminal No. 10 (Blue/Yellow wire) through common connector. APP sensor 6-pin harness connector terminal "D" and PCM 104-pin harness connector terminal No. 43 (Gray wire) through common connector. APP sensor 6-pin harness connector terminal "E" and PCM 104-pin harness connector terminal No. 40. APP sensor 6-pin harness connector terminal "F" and PCM 104-pin harness connector terminal No. 9 (White wire) through common connector. If continuity is present, go to next step. If continuity is not present, repair open circuit in suspect wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
7. Check for continuity between following: Short Circuit Inspection APP sensor 6-pin harness connector terminal "A" (Red/Black wire) and power supply. APP sensor 6-pin harness connector terminal "A" (Red/Black wire) and body ground. APP sensor 6-pin harness connector terminal "B" (Brown wire) and power supply. APP sensor 6-pin harness connector terminal "B" (Brown wire) and body ground. APP sensor 6-pin harness connector terminal "C" (Blue/Yellow wire) and power supply. APP sensor 6-pin harness connector terminal "C" (Blue/Yellow wire) and body ground. APP sensor 6-pin harness connector terminal "D" (Gray wire) and power supply. APP sensor 6-pin harness connector terminal "D" (Gray wire) and body ground. APP sensor 6-pin harness connector terminal "E" (Red/Green wire) and power supply. APP sensor 6-pin harness connector terminal "E" (Red/Green wire) and body ground. APP sensor 6-pin harness connector terminal "F" (White wire) and power supply. APP sensor 6-pin harness connector terminal "F" (White wire) and body ground. If continuity is present, repair short circuit in suspect wire or replace wire harness.

Scheme 142

1. Connected scan tool to DLC-2. Turn ignition on, engine off. Select BARO PID. Verify BARO PID and barometric pressure are practically equal. If as verified, go to next step. If not as verified, check for open or short circuit. Go to step 3.
2. Apply vacuum of -7.38 in. Hg to BARO sensor, and verify BARO PID (pressure) from that of step 1) is about 7.38 in. Hg. If not as verified, check for open or short circuit. Go to next step.
3. Open Circuit Inspection Disconnect Barometric Pressure (BARO) sensor 3-pin harness connector. (Scheme 143) Disconnect PCM harness connectors. Check for continuity between following terminals: BARO sensor 3-pin harness connector terminal "A" and PCM 30-pin harness connector terminal No. 1G (Pink wire). BARO sensor 3-pin harness connector terminal "B" and PCM 30-pin harness connector terminal No. 2H (Brown wire). BARO sensor 3-pin harness connector terminal "C" and PCM 30-pin harness connector terminal No. 2K (Red/Black wire). If continuity is present, go to next step. If continuity is not present, repair open circuit in suspect wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
4. Short Circuit Inspection Check for continuity between following: BARO sensor 3-pin harness connector terminal "C" (Red/Black wire) and power supply. BARO sensor 3-pin harness connector terminal "C" (Red/Black wire) and ground. BARO sensor 3-pin harness connector terminal "A" (Pink wire) and power supply. BARO sensor 3-pin harness connector terminal "A" (Pink wire) and ground. If continuity is present, repair short circuit in suspect wire or replace wire harness. If open or short circuit is not present, replace BARO sensor.

Scheme 143

BRAKELIGHT SWITCH

Note. MAZDA6 combines brake switch with brakelight switch. For brake switch testing refer to appropriate CRUISE CONTROL SYSTEMS article in ACCESSORIES & EQUIPMENT.

Disconnect brakelight switch harness connector. Using ohmmeter, check continuity between brakelight switch terminals. With brake pedal released, continuity should not be present. With brake pedal depressed, continuity should be present. If continuity is not as specified, replace brakelight switch.

Camshaft Position Sensor - MAZDA6 (2.3L)

1. Resistance Inspection Disconnect CMP sensor harness connector. Measure resistance between CMP sensor terminals "A" and "B" using a DVOM. If CMP sensor resistance reading is 400-550 ohms, go to next step. If resistance reading is not as specified, replace CMP sensor. See «CAMSHAFT POSITION SENSOR»(ref-151901-S26280287582003010900000) under ENGINE SENSORS & SWITCHES in REMOVAL OVERHAUL & INSTALLATION article.
2. Open Circuit Inspection Disconnect PCM 30-pin harness connector. Check continuity between following terminals: CMP sensor harness connector terminal "A" (Brown/White wire) and PCM 30-pin harness connector terminal No. 2M (White wire). CMP sensor harness connector terminal "B" (White/Violet wire) and PCM 30-pin harness connector terminal No. 2J (Black wire). If continuity is present, go to next step. If continuity is not present, repair open circuit in suspect wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
3. Short Circuit Inspection Check for continuity between following: CMP sensor harness connector terminal "A" (Brown/White wire) and power supply. CMP sensor harness connector terminal "A" (Brown/White wire) and body GND. CMP sensor harness connector terminal "B" (White/Violet wire) and power supply. CMP sensor harness connector terminal "B" (White/Violet wire) and body GND. If continuity is present, repair short circuit in suspect wire or replace wire harness.

Camshaft Position Sensor - MAZDA6 (3.0L)

1. Disconnect negative battery cable. Disconnect appropriate CMP sensor harness connector (left or right sensor). Measure resistance between CMP sensor terminals "A" and "B" with DVOM. If CMP sensor resistance reading is 467-571 ohms but PID value is out of specification, go to next step. If resistance reading is not as specified, replace CMP sensor. See «CAMSHAFT POSITION SENSOR»(ref-151901-S26280287582003010900000) under ENGINE SENSORS & SWITCHES in REMOVAL OVERHAUL & INSTALLATION article.
2. Open Circuit Inspection Disconnect PCM 104-pin harness connector. Check for continuity between following terminals: CMP sensor (RH) harness connector terminal "A" (White/Black wire) and PCM 104-pin harness connector terminal No. 85 (Black wire). CMP sensor (RH) harness connector terminal "B" (Brown/Yellow wire) and PCM 104-pin harness connector terminal No. 86 (White wire). CMP sensor (LH) harness connector terminal "A" (White/Green wire) and PCM 104-pin harness connector terminal No. 58 (Brown wire). CMP sensor (LH) harness connector terminal "B" (Brown/White wire) and PCM 104-pin harness connector terminal No. 59 (Yellow wire). If continuity is present, go to next step. If continuity is not present, repair open circuit in suspect wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
3. Short Circuit Inspection Check for continuity between following: Between CMP sensor (RH) harness connector terminal "A" (White/Black wire) and power supply. Between CMP sensor (RH) harness connector terminal "A" (White/Black wire) and body ground. Between CMP sensor (RH) harness connector terminal "B" (Brown/Yellow wire) and power supply. Between CMP sensor (RH) harness connector terminal "B" (Brown/Yellow wire) and body ground. Between CMP sensor (LH) harness connector terminal "A" (White/Green wire) and power supply. Between CMP sensor (LH) harness connector terminal "A" (White/Green wire) and body ground. Between CMP sensor (LH) harness connector terminal "B" (Brown/White wire) and power supply. Between CMP sensor (LH) harness connector terminal "B" (Brown/White wire) and body ground.

If continuity is present, repair short circuit in suspect wire or replace wire harness.

Camshaft Position Sensor - Miata

Note. May require removal of PCM to gain access to wire terminals.

Scheme 144

Scheme 145

1. Remove and inspect Camshaft Position (CMP) sensor 3-pin harness connector. Clean off any metal particles or shavings. Reinstall CMP sensor. See «CAMSHAFT POSITION SENSOR»(ref-151901-S26280287582003010900000) under ENGINE SENSORS & SWITCHES in REMOVAL, OVERHAUL & INSTALLATION article.
2. Connect scan tool to DLC-2. Start engine. Using scan tool, enter vehicle information. Connect oscilloscope positive test lead to PCM 24-pin harness connector terminal No. 3V (Gray/Blue wire) and negative test lead to 31-pin harness connector terminal No. 4AF (White/Red wire). (Scheme 144) Select DIGITAL MEASUREMENT SYSTEM, then FREQUENCY METER. Press link key to select RPM PID. Select PID/DATA MONITOR, then PCM. Press START.
3. Set oscilloscope to 2.0V/DIV (Y), 20ms/DIV (X), DC range. Inspect wave profile with engine idling. (Scheme 145) If wave profile or voltage readings are not as specified, check following harnesses: Check for open or short in CMP signal circuit between CMP sensor 3-pin harness connector terminal "B" and PCM 24-pin harness connector terminal No. 3V (Gray/Blue wire). Check for open or short in power circuit between CMP sensor 3-pin harness connector terminal "A" and main relay 4-pin harness connector terminal "D" through common connector (White/Red wire). Check for open in ground circuit (Black/Blue wire) between CMP sensor 3-pin harness connector terminal "C" and PCM 31-pin harness connector terminal No. 4A. Repair or replace as necessary. Reconnect CMP sensor. Check protrusion on intake camshaft for damage and cracks. Repair as necessary.

Camshaft Position Sensor - MPV

1. Disconnect Camshaft Position (CMP) sensor connector. (Scheme 146) Measure resistance between CMP sensor connector terminals. Resistance reading should be 308-376 ohms. If resistance reading is okay but PID value or voltage is out of specification, check for open or short circuit. Go to next step. If resistance is not as specified, replace CMP sensor. See «CAMSHAFT POSITION SENSOR»(ref-151901-S26280287582003010900000) under ENGINE SENSORS & SWITCHES in REMOVAL, OVERHAUL & INSTALLATION article.
2. Open Circuit Inspection Disconnect PCM 104-pin harness connector. Connect 104-Pin Breakout Box (49-UN01-130) to PCM harness connector only. (Scheme 147) Check continuity between following terminals: CMP sensor harness connector terminal "A" (Brown/Light Green wire) and breakout box terminal No. 85. (Scheme 148) CMP sensor harness connector terminal "B" (Blue/Orange wire) and breakout box terminal No. 86. If continuity is present, go to next step. If continuity is not present, repair open circuit in suspect wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
3. Short Circuit Inspection Check for continuity between following: Between CMP sensor harness connector terminal "A" (Brown/Light Green wire) and power. Between CMP sensor harness connector terminal "A" (Brown/Light Green wire) and ground. Between CMP sensor harness connector terminal "B" (Blue/Orange wire) and power. Between CMP sensor harness connector terminal "B" (Blue/Orange wire) and ground.

If continuity is present, repair short circuit in suspect wire or replace wire harness.

Scheme 146

Scheme 147

Scheme 148

Camshaft Position Sensor - Protege & Protege5

1. Disconnect Camshaft Position (CMP) sensor 2-pin harness connector. CMP sensor is located near front of valve cover. Using DVOM, measure resistance between CMP sensor connector terminals. If resistance reading is 950-1250 ohms, go to next step. If resistance reading is not as specified, replace CMP sensor. See «CAMSHAFT POSITION SENSOR»(ref-151901-S26280287582003010900000) under ENGINE SENSORS & SWITCHES in REMOVAL, OVERHAUL & INSTALLATION article.
2. Open Circuit Inspection Disconnect PCM 104-pin harness connector and install 104-Pin Breakout Box (49-UN01-130) to PCM harness connector only. (Scheme 147) Check for open or short circuit between following terminals: CMP sensor harness connector terminal "A" (Blue wire) and breakout box terminal No. 85. See «CMP/PCM TERMINAL IDENTIFICATION (PROTEGE & PROTEGE5)»(ref-151892-S03061800522003010800000) table. CMP sensor harness connector terminal "B" (Green wire) and breakout box terminal No. 86. Repair suspect wire or replace wire harness as necessary. If short or open circuit is not found, replace CMP sensor.

CMP/PCM TERMINAL IDENTIFICATION (PROTEGE & PROTEGE5)

1. Ensure clutch switch is installed correctly. Disconnect clutch switch 5-pin harness connector. Remove clutch switch. Using DVOM, check for continuity between clutch switch terminals "B" and "D". (Scheme 149) If clutch switch rod is released, continuity should be present between clutch switch terminals. If clutch rod is pushed, continuity should not be present. If clutch switch is okay, but PID value is out of specification, go to next step. If continuity is not as specified, replace clutch switch.
2. Open Circuit Inspection Disconnect PCM 30-pin harness connector. Back probe clutch switch 5-pin harness connector. (Scheme 150) Check for continuity between following terminals: Clutch switch 5-pin harness connector terminal "B" and PCM 30-pin harness connector terminal No. 1R (White/Green wire). Clutch switch 5-pin harness connector terminal "D" (Black wire) and ground. If continuity is present, go to next step. If continuity is not present, repair open circuit in suspect wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
3. Short Circuit Inspection Check for continuity between following: Clutch switch 5-pin harness connector terminal "B" (White/Green wire) and power supply. Clutch switch 5-pin harness connector terminal "B" (White/Green wire) and ground. If continuity is present, repair short circuit in suspect wire or replace wire harness.

Scheme 149

Scheme 150

1. Disconnect negative battery cable. Disconnect clutch switch 5-pin harness connector. Remove clutch switch. Using DVOM, check for continuity between clutch switch terminals "B" and "D". If clutch switch rod is released, continuity should be present. If clutch rod is pushed, continuity should not be present. If clutch switch is okay, but PID value is out of specification, go to next step. If continuity is not as specified, replace clutch switch.
2. Open Circuit Inspection Disconnect PCM 104-pin harness connector. Back probing clutch switch 5-pin harness connector, check for continuity between following terminals: Clutch switch 5-pin harness connector terminal "B" and PCM 104-pin harness connector terminal No. 17 (White/Green wire). Clutch switch 5-pin harness connector terminal "D" (Black wire) and ground. If continuity is present, go to next step. If continuity is not present, repair open circuit in suspect wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
3. Short Circuit Inspection Check for continuity between following: Clutch switch 5-pin harness connector terminal "B" (White/Green wire) and power supply. Clutch switch 5-pin harness connector terminal "B" (White/Green wire) and ground. If continuity is present, repair short circuit in White/Green wire or replace wire harness.

Miata

1. Disconnect clutch switch harness connector. Remove clutch switch. Using ohmmeter, check continuity between switch terminals. With clutch rod released, continuity should be present. With clutch rod depressed, continuity should not be present. If continuity is as specified, check for open or short circuit. Go to next step. If continuity is not as specified, replace clutch switch.
2. Open Circuit Inspection Check for continuity in following circuits: Power circuit (White/Green wire) between clutch switch harness connector terminal "A" and PCM 31-pin harness connector terminal No. 4I through common connector. Ground circuit between ground and clutch switch harness connector terminal "B" (Black wire). If continuity is present, go to next step. If continuity is not present, repair open circuit in suspect wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
3. Short Circuit Inspection Check for continuity to ground in White/Green wire between clutch switch harness connector terminal "A" and PCM 31-pin harness connector terminal No. 4I through common connector. If continuity is present, repair short circuit to ground or replace wire harness.

Protege & Protege5

1. Disconnect clutch switch harness connector. Remove clutch switch. Using ohmmeter, check continuity between clutch switch terminals. With clutch rod released, continuity should be present. With clutch rod depressed, continuity should not be present. If continuity is as specified, check for open or short circuit. Go to next step. If continuity is not as specified, replace clutch switch.
2. Open Circuit Inspection Disconnect PCM 104-pin harness connector and install 104-Pin Breakout Box (49-UN01-130) to PCM harness connector only. (Scheme 147) Check for continuity in following circuits: Check for open in signal circuit between clutch switch harness connector terminal "B" (White/Green wire) and breakout box terminal No. 6 through common connector. Check for open in ground circuit between ground and clutch switch harness connector terminal "A" (Black wire). If continuity is present, go to next step. If continuity is not present, repair open circuit in suspect wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
3. Short Circuit Inspection Check for continuity to ground in signal circuit between clutch switch harness connector terminal "B" (White/Green wire) and breakout box terminal No. 6 through common connector. If continuity is present, repair short circuit to ground in White/Green wire between clutch switch harness connector terminal "B" and PCM 104-pin harness connector terminal No. 6 through common connector or replace wire harness.

CRANKSHAFT POSITION SENSOR

Note. Miata CKP sensor resistance testing not available from manufacturer.

Crankshaft Position Sensor Resistance - MAZDA6 (2.3L)

1. Disconnect Crankshaft Position (CKP) sensor 2-pin harness connector. Using DVOM, measure resistance between terminals "A" and "B". Resistance reading should be 400-550 ohms. If resistance reading is as specified but PID value is out of specification, go to next step. If resistance reading is not as specified, replace CKP sensor. See «CRANKSHAFT POSITION SENSOR»(ref-151901-S06665823822003010900000) under ENGINE SENSORS & SWITCHES in REMOVAL, OVERHAUL & INSTALLATION article.
2. Open Circuit Inspection Disconnect PCM 30-pin harness connector. Using DVOM, check for continuity between following terminals: CKP sensor harness connector terminal "A" and PCM 30-pin harness connector terminal No. 2D (Blue wire). CKP sensor harness connector terminal "B" and PCM 30-pin harness connector terminal No. 2G (Green wire). If continuity is present, go to next step. If continuity is not present, repair open circuit in suspect wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
3. Short Circuit Inspection Check for continuity between following: CKP sensor harness connector terminal "A" (Blue wire) and power supply. CKP sensor harness connector terminal "A" (Blue wire) and body GND. CKP sensor harness connector terminal "B" (Green wire) and power supply. CKP sensor harness connector terminal "B" (Green wire) and body GND. If continuity is present, repair short circuit in suspect wire or replace wire harness.

Crankshaft Position Sensor Resistance - MAZDA6 (3.0L)

1. Disconnect Crankshaft Position (CKP) sensor 2-pin harness connector. Using DVOM, measure resistance between terminals "A" and "B". Resistance reading should be 315-385 ohms. If resistance reading is as specified but PID value is out of specification, go to next step. If resistance reading is not as specified, replace CKP sensor. See «CRANKSHAFT POSITION SENSOR»(ref-151901-S06665823822003010900000) under ENGINE SENSORS & SWITCHES in REMOVAL, OVERHAUL & INSTALLATION article.
2. Open Circuit Inspection Disconnect PCM 104-pin harness connector. Using DVOM, check for continuity between following terminals: CKP sensor harness connector terminal "A" (Brown/Blue wire) and PCM 104-pin harness connector terminal No. 22 (Green wire). CKP sensor harness connector terminal "B" (White/Red wire) and PCM 104-pin harness connector terminal No. 21 (Blue wire). If continuity is present, go to next step. If continuity is not present, repair open circuit in suspect wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
3. Short Circuit Inspection Check for continuity between following: CKP sensor harness connector terminal "A" (Brown/Blue wire) and power supply. CKP sensor harness connector terminal "A" (Brown/Blue wire) and body GND. CKP sensor harness connector terminal "B" (White/Red wire) and power supply. CKP sensor harness connector terminal "B" (White/Red wire) and body GND. If continuity is present, repair short circuit in suspect wire or replace wire harness.

MPV

1. Disconnect Crankshaft Position (CKP) sensor 2-pin harness connector. Using DVOM, measure resistance between terminals "A" and "B". Resistance reading should be 315-385 ohms. If resistance reading is as specified but PID value is out of specification, go to next step. If resistance reading is not as specified, replace CKP sensor. See «CRANKSHAFT POSITION SENSOR»(ref-151901-S06665823822003010900000) under ENGINE SENSORS & SWITCHES in REMOVAL, OVERHAUL & INSTALLATION article.
2. Open Circuit Inspection Disconnect PCM 104-pin harness connector. Connect 104-Pin Breakout Box (49-UN01-130) to PCM harness connector only. Using DVOM, check for continuity between following terminals: CKP sensor harness connector terminal "A" (Gray/Yellow wire) and breakout box terminal No. 22 (Pink wire). CKP sensor harness connector terminal "B" (Black/Pink wire) and breakout box terminal No. 21 (Green wire). If continuity is present, go to next step. If continuity is not present, repair open circuit in suspect wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
3. Short Circuit Inspection Check for continuity between following: CKP sensor harness connector terminal "A" (Gray/Yellow wire) and power supply. CKP sensor harness connector terminal "A" (Gray/Yellow wire) and body GND. CKP sensor harness connector terminal "B" (Black/Pink wire) and power supply. CKP sensor harness connector terminal "B" (Black/Pink wire) and body GND. If continuity is present, repair short circuit in suspect wire or replace wire harness.

Crankshaft Position Sensor Resistance - Protege & Protege5

1. Disconnect Crankshaft Position (CKP) sensor 3-pin harness connector. Using DVOM, measure resistance between terminals "A" and "B". (Scheme 151) Resistance reading should be about 550 ohms. If resistance reading is as specified but PID value is out of specification, go to next step. If resistance reading is not as specified, replace CKP sensor. See «CRANKSHAFT POSITION SENSOR»(ref-151901-S06665823822003010900000) under ENGINE SENSORS & SWITCHES in REMOVAL, OVERHAUL & INSTALLATION article.
2. Open Circuit Inspection Disconnect PCM 104-pin harness connector. Connect 104-Pin Breakout Box (49-UN01-130) to PCM harness connector only. Using DVOM, check for continuity in following circuits: CKP signal circuit between CKP sensor 3-pin harness connector terminal "A" (Yellow wire) and breakout box terminal No. 21. CKP signal circuit between CKP sensor 3-pin harness connector terminal "B" (Orange/Black wire) and breakout box terminal No. 22. If continuity is not present, repair open circuit in suspect wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS. If open circuit is not present, replace CKP sensor.
3. Short Circuit Inspection Check for continuity between following: CKP signal circuit between CKP sensor 3-pin harness connector terminal "A" (Yellow wire) and breakout box terminal No. 21 to ground. CKP signal circuit between CKP sensor 3-pin harness connector terminal "B" (Orange/Black wire) and breakout box terminal No. 22 to ground. If continuity is present, repair short in suspect circuit or replace wire harness. If short circuit is not present, replace CKP sensor.

Scheme 151

Crankshaft Position Sensor Air Gap - Miata, Protege & Protege5

Note. Mazda6 and MPV air gap inspection procedure and specification not available from manufacturer.

Using a feeler gauge, measure air gap between crankshaft pulley and Crankshaft Position (CKP) sensor. (Scheme 152)and (Scheme 153). If air gap is not.020-.060" (.5-1.5 mm), replace crankshaft pulley or CKP sensor. On Miata, CKP sensor is adjustable. If sensor will not adjust, replace CKP sensor or plate behind crankshaft pulley. See CRANKSHAFT POSITION SENSOR under ENGINE SENSORS & SWITCHES in REMOVAL, OVERHAUL & INSTALLATION article.

Scheme 152

Scheme 153

EGR BOOST SENSOR

Note. Do not apply vacuum beyond specification. Will damage EGR boost sensor.

EGR Boost Sensor - Except MAZDA6 (3.0L) & Miata

1. Voltage Inspection Disconnect PCM 104-pin harness connector and install 104-Pin Breakout Box (49-UN01-130) to PCM and PCM harness connector. (Scheme 147) Turn ignition on. Disconnect vacuum hose from between EGR boost sensor and EGR boost sensor solenoid valve. Connect vacuum pump to EGR boost sensor port. Ensure breakout box terminal No. 34 voltage reading is 2.3-4.7 volts. Apply 7.85 in. Hg to EGR boost sensor and verify breakout box terminal No. 34 voltage drops to 0.8-1.3 volts. If EGR boost sensor voltage reading is not as specified, check for open or short circuit. Go to next step.
2. Open Circuit Inspection Check for continuity in following circuits: EGR boost (Barometric pressure) signal circuit between EGR boost sensor 3-pin harness connector terminal "A" and breakout box terminal No. 34. (Scheme 154) Constant voltage circuit between EGR boost sensor 3-pin harness connector terminal "C" and breakout box terminal No. 90. GND circuit between EGR boost sensor 3-pin harness connector terminal "B" and breakout box terminal No. 91. If continuity is not present, repair open circuit in suspect wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS. If open circuit is not present, replace CKP sensor.
3. Short Circuit Inspection Check for continuity between following terminals: EGR boost (Barometric pressure) signal circuit between EGR boost sensor 3-pin harness connector terminal "A" and breakout box terminal No. 34. Constant voltage circuit between EGR boost sensor 3-pin harness connector terminal "C" and breakout box terminal No. 90. If continuity is present, repair short circuit in suspect wire or replace wire harness.

Scheme 154

EGR Boost Sensor - MAZDA6 (3.0L)

1. Voltage Inspection Connect scan tool to DLC-2. Turn ignition on, engine off. Select BARO PID on scan tool. Verify BARO PID (pressure) and barometric pressure are practically equal. If as verified, go to next step. If not as verified, go to step 3 .
2. Apply -7.38 in. Hg to EGR boost sensor and ensure BARO PID variation from step 1 is about 7.38 in. Hg. If not as verified, go to next step. If as verified, replace EGR boost sensor.
3. Open Circuit Inspection Check for continuity between following terminals: EGR boost sensor 3-pin harness connector terminal "A" and PCM 104-pin harness connector terminal No. 34 (Pink wire). EGR boost sensor 3-pin harness connector terminal "B" and PCM 104-pin harness connector terminal No. 91 (Brown wire). EGR boost sensor 3-pin harness connector terminal "C" and PCM 104-pin harness connector terminal No. 90 (Red/Black wire). If continuity is present, go to next step. If continuity is not present, repair open circuit in suspect wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
4. Short Circuit Inspection Check for continuity between following: EGR boost sensor 3-pin harness connector terminal "A" (Pink wire) and power supply. EGR boost sensor 3-pin harness connector terminal "A" (Pink wire) and ground. EGR boost sensor 3-pin harness connector terminal "B" (Brown wire) and power supply. EGR boost sensor 3-pin harness connector terminal "C" (Red/Black wire) and power supply. EGR boost sensor 3-pin harness connector terminal "C" (Red/Black wire) and ground. If continuity is present, repair short circuit in suspect wire or replace wire harness.

EGR Boost Sensor (Miata)

1. Inspect EGR boost sensor for damage or cracks. Inspect vacuum hose for improper routing, kinks or leaks. If no problems are found with vacuum hose or EGR boost sensor, go to next step. If any problems are found, repair as necessary.
2. Open Circuit Inspection Check for continuity in following circuits: EGR boost circuit between EGR boost sensor 3-pin harness connector terminal "B" (Blue/Yellow wire) and PCM 31-pin harness connector terminal No. 4AE. (Scheme 154) Reference voltage circuit between EGR boost sensor 3-pin harness connector terminal "C" and PCM 31-pin harness connector terminal No. 4L. GND circuit between EGR boost sensor 3-pin harness connector terminal "A" and PCM 31-pin harness connector terminal No. 4O through common connector. If continuity is present, go to next step. If continuity is not present, repair open circuit in suspect wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
3. Short Circuit Inspection Check for continuity between following: EGR boost sensor 3-pin harness connector terminal "C" and PCM 31-pin harness connector terminal No. 4L through common connector to GND. EGR boost sensor connector 3-pin harness connector terminal "B" and PCM 31-pin harness connector terminal No. 4AE through common connector to GND. If continuity is present, repair open circuit in suspect wire or replace wire harness.

1. Resistance Inspection Remove Engine Coolant Temperature (ECT) sensor. Place ECT sensor in water with thermometer, and heat water gradually. Using DVOM, measure resistance at specified temperatures. See «ENGINE COOLANT TEMPERATURE (ECT) SENSOR SPECIFICATIONS»(ref-151892-S11826414102003010900000) table. If ECT sensor is okay, but PID value is out of specification, check for open or short circuit. Go to next step. If resistance reading is not as specified, replace ECT sensor.
2. Open Circuit Inspection Check for continuity between following terminals: ECT sensor harness connector terminal "A" and PCM 30-pin harness connector terminal No. 1M (Light Green/black wire). ECT sensor harness connector terminal "B" and PCM 30-pin harness connector terminal No. 2H (Brown wire). If continuity is present, go to next step. If continuity is not present, repair open circuit in suspect wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
3. Short Circuit Inspection Check for continuity between following: ECT sensor harness connector terminal "A" (Light Green/Black wire) and power supply. ECT sensor harness connector terminal "A" (Light Green/Black wire) and body GND. ECT sensor harness connector terminal "B" (Brown wire) and power supply. If continuity is present, repair short circuit in suspect wire or replace wire harness.

1. Resistance Inspection Remove Engine Coolant Temperature (ECT) sensor. Place ECT sensor in water with thermometer, and heat water gradually. Using DVOM, measure resistance at specified temperatures. See «ENGINE COOLANT TEMPERATURE (ECT) SENSOR SPECIFICATIONS»(ref-151892-S11826414102003010900000) table. If ECT sensor is okay, but PID value is out of specification, check for open or short circuit. Go to next step. If resistance reading is not as specified, replace ECT sensor.
2. Open Circuit Inspection Check for continuity between following terminals: ECT sensor harness connector terminal "A" (White/Blue wire) and PCM 104-pin harness connector terminal No. 38 (Light Green/Black wire). ECT sensor harness connector terminal "B" (Red/Green wire) and PCM 104-pin harness connector terminal No. 91 (Brown wire). If continuity is present, go to next step. If continuity is not present, repair open circuit in suspect wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
3. Short Circuit Inspection Check for continuity between following: ECT sensor harness connector terminal "A" (White/Blue wire) and power supply. ECT sensor harness connector terminal "A" (White/Blue wire) and body GND. ECT sensor harness connector terminal "B" (Red/Green wire) and power supply. If continuity is present, repair short circuit in suspect wire or replace wire harness.

MPV, Protege & Protege5

1. Resistance Inspection Disconnect Engine Coolant Temperature (ECT) sensor 2-pin harness connector. Remove ECT sensor. Place sensor and a thermometer in a container of water. Connect ohmmeter between ECT sensor terminals. Slowly heat water. Observe resistance reading at specified temperatures. See «ENGINE COOLANT TEMPERATURE (ECT) SENSOR SPECIFICATIONS»(ref-151892-S11826414102003010900000) table. If ECT sensor resistance reading is as specified but PID value is not within specification, perform open or short circuit inspection. Go to next step. If resistance reading is not as specified, replace ECT sensor.
2. Open Circuit Inspection Disconnect PCM 104-pin harness connector and install 104-Pin Breakout Box (49-UN01-130) to PCM harness connector only. (Scheme 147) Check for continuity in following circuits: ECT signal circuit between ECT sensor harness connector terminal "A" and breakout box terminal No. 38 through common connector. GND circuit between ECT sensor harness connector terminal "B" and breakout box terminal No. 91. If continuity is present, go to next step. If continuity is not present, repair open circuit in suspect wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
3. Short Circuit Inspection Check for continuity in following circuits: ECT signal circuit between ECT sensor harness connector terminal "A" and PCM 104-pin harness connector terminal No. 38 to ground. ECT signal circuit between ECT sensor harness connector terminal "A" and PCM 104-pin harness connector terminal No. 38 to power supply. GND circuit between ECT sensor harness connector terminal "B" and PCM 104-pin harness connector terminal No. 91 to power supply. If continuity is present, repair short circuit in suspect wire or replace wire harness. If open or short circuit is not present, replace ECT sensor.

Note. Coolant temperature sender is part of ECT sensor.

1. ECT Sensor Testing Procedure Disconnect ECT sensor 3-pin harness connector. Remove ECT sensor. ECT sensor is located on left side of engine. Place ECT sensor and a thermometer in a container of water. Connect ohmmeter between ECT sensor terminals "A" and "B". (Scheme 156) Slowly heat water. Observe resistance reading at specified temperatures. See «ENGINE COOLANT TEMPERATURE (ECT) SENSOR SPECIFICATIONS»(ref-151892-S11826414102003010900000) table. If ECT sensor is okay, but PID value is not within specification, check for open or short circuit. Go to next step. If resistance reading is not as specified, replace ECT sensor.
2. Open Circuit Inspection Check for continuity in following circuits: Reference voltage circuit (Red/Blue wire) between ECT sensor 3-pin harness connector terminal "A" and PCM 31-pin harness connector terminal No. 4P through common connector. (Scheme 155) GND circuit (Black/Red wire) between ECT sensor 3-pin harness connector terminal "B" and PCM 31-pin harness connector terminal No. 4O through common connector. If continuity is present, go to next step. If continuity is not present, repair open circuit in suspect wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
3. Short Circuit Inspection Check for continuity in reference voltage circuit (Red/Blue wire) between ECT sensor 3-pin harness connector terminal "A" and PCM 31-pin harness connector terminal No. 4P through common connector to ground. If continuity is present, repair short circuit in Red/Blue wire between ECT sensor 3-pin harness connector terminal "A" and PCM 31-pin harness connector terminal No. 4P or replace wire harness. If wire harness is okay, replace ECT sensor.
4. Engine Coolant Sender Testing Procedure To check coolant temperature sender portion of ECT sensor, measure resistance between ground and ECT sensor terminal "C" (with ECT sensor installed). (Scheme 156) Resistance should be 160-230 ohms with sensor temperature at 122°F (50°C). If engine coolant sender resistance is not within specification, replace ECT sensor.

ENGINE COOLANT TEMPERATURE (ECT) SENSOR SPECIFICATIONS

Scheme 155

Scheme 156

FUEL TANK PRESSURE SENSOR

Protege & Protege5 (Only)

1. Disconnect PCM 104-pin harness connector. Connect 104-Pin Breakout Box (49-UN01-130) to PCM harness connector and then to PCM. (Scheme 147) Turn ignition on. Connect DVOM to breakout box terminal No. 62.
2. Apply pressure then vacuum to Fuel Tank Pressure (FTP) sensor. See «FUEL TANK PRESSURE SENSOR SPECIFICATIONS»(ref-151892-S18980653702003010900000) table. Decrease applied pressure from +1.97 in. Hg to -1.97 in. Hg and verify breakout box terminal No. 62 voltage reading decreases as specified. If FTP sensor faulty, replace FTP sensor. If FTP sensor is okay, but breakout box terminal No. 62 voltage reading is out of specification, disconnect FTP sensor 3-pin harness connector and check wire harness for open or short circuits. Go to next step.
3. Open Circuit Inspection Check for continuity between following terminals: FTP signal circuit between FTP sensor 3-pin harness connector terminal "B" and breakout box terminal No. 62 through common connector. (Scheme 157) Constant voltage circuit between FTP sensor 3-pin harness connector terminal "C" and breakout box terminal No. 90 through common connector. GND circuit between FTP sensor 3-pin harness connector terminal "A" and breakout box terminal No. 91 through common connector. If continuity is present, go to next step. If continuity is not present, repair open circuit in suspect wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS. FUEL TANK PRESSURE SENSOR SPECIFICATIONS Application - Applied Vacuum Output Voltage -1.07 in. Hg.45-.55 0 in. Hg 2.25-2.75 +1.97 in. Hg 4.05-4.95
4. Short Circuit Inspection Check for continuity between following terminals: FTP signal circuit between FTP sensor 3-pin harness connector terminal "B" and breakout box terminal No. 62 through common connector. Constant voltage circuit between FTP sensor 3-pin harness connector terminal "C" and breakout box terminal No. 90 through common connector. If continuity is present, repair open circuit in suspect wire or replace wire harness. If wire harness is okay, replace FTP sensor.

Scheme 157

1. Voltage Inspection Warm engine to normal operating temperature. Allow engine to idle. Disconnect HO2S 4-pin harness connectors (front or rear). Connect analog voltmeter test leads to HO2S 4-pin connector terminals "A" and "B". (Scheme 158) Increase engine RPM to 3000 until voltmeter reads about 0.5-0.7 volt. Ensure voltmeter needle moves while increasing or decreasing engine speed suddenly several times. See «HO2S VOLTAGE SPECIFICATIONS»(ref-151892-S07817094092003010900000) table. If voltmeter needle moves as specified, but PID value voltage readings are out of specification, check for open or short circuit between PCM and HO2S. Go to next step. If voltmeter needle does not move with engine speed, replace HO2S.
2. Open Circuit Inspection Disconnect appropriate PCM 30-pin harness connector. Check for continuity between following terminals: Front HO2S 4-pin harness connector terminal "A" and PCM 30-pin harness connector terminal No. 1AB (Black wire). Front HO2S 4-pin harness connector terminal "B" and PCM 30-pin harness connector terminal No. 2H (Brown wire). Rear HO2S 4-pin harness connector terminal "A" and PCM 30-pin harness connector terminal No. 1Y (White/Blue wire). Rear HO2S 4-pin harness connector terminal "B" and PCM 30-pin harness connector terminal No. 2H (Brown wire). If continuity is present, go to next step. If continuity is not present, repair open circuit in suspect wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
3. Short Circuit Inspection Disconnect PCM 104-pin harness connector. Check for continuity between following terminals: Front HO2S 4-pin harness connector terminal "A" (Black wire) and body GND. Front HO2S 4-pin harness connector terminal "A" (Black wire) and power supply. Front HO2S 4-pin harness connector terminal "B" (Brown wire) and power supply. Rear HO2S 4-pin harness connector terminal "A" (White/Blue wire) and body GND. Rear HO2S 4-pin harness connector terminal "A" (White/Blue wire) and power supply. Rear HO2S 4-pin harness connector terminal "B" (Brown wire) and power supply. If continuity is present, repair short circuit in suspect wire or replace wire harness.
4. HO2S Heater Resistance Inspection Allow sensor to cool to room temperature. Disconnect front or rear HO2S 4-pin harness connector. Measure resistance between front HO2S 4-pin connector terminals "C" and "D". (Scheme 158) Resistance reading should be 3.0-3.6 ohms at 68°F (20°C). Measure resistance between rear HO2S 4-pin connector terminals "C" and "D". (Scheme 158) Resistance reading should be 5-7 ohms. If resistance reading is not as specified, replace suspect HO2S. If HO2S is okay but PID value is out of specification, check for open or short circuit. Go to next step.
5. Open Circuit Inspection Check for continuity between following terminals: Front HO2S 4-pin harness connector terminal "C" and main relay 4-pin harness connector terminal "C" (White/Red wire). Front HO2S 4-pin harness connector terminal "D" and PCM 30-pin harness connector terminal No. 4A (White/Black wire). Rear HO2S 4-pin harness connector terminal "C" (White/Red wire) and ground. Rear HO2S 4-pin harness connector terminal "D" (White/Black wire) and power supply. Rear HO2S 4-pin harness connector terminal "D" (White/Black wire) and ground. If continuity is present, go to next step. If continuity is not present, repair open circuit in suspect wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
6. Short Circuit Inspection Check for continuity between following terminals: Front HO2S 4-pin harness connector terminal "A" (Black wire) and ground. Front HO2S 4-pin harness connector terminal "A" (Black wire) and power supply. Front HO2S 4-pin harness connector terminal "B" (Brown wire) and power supply. Rear HO2S 4-pin harness connector terminal "A" (White/Blue wire) and ground. Rear HO2S 4-pin harness connector terminal "A" (White/Blue wire) and power supply. Rear HO2S 4-pin harness connector terminal "B" (Brown wire) and power supply. If continuity is present, repair short circuit to ground in suspect wire or replace wire harness as necessary.

HO2S VOLTAGE SPECIFICATIONS

Scheme 158

1. Voltage Inspection Warm engine to normal operating temperature. Disconnect HO2S 4-pin harness connector. Connect voltmeter between ground and HO2S 4-pin connector terminal "A". (Scheme 159) Run engine at 3000 RPM until voltmeter indicates 0-1 volt. Ensure voltage changes within specification when engine RPM is increased or decreased several times. See «HO2S VOLTAGE SPECIFICATIONS»(ref-151892-S07817094092003010900000) table. If voltage reading does not change as specified, replace suspect HO2S. If HO2S is okay but PID value is not as specified, go to next step.
2. Open Circuit Inspection Disconnect PCM 104-pin harness connector. Check for continuity between following terminals: Right front HO2S 4-pin harness connector terminal "A" and PCM 104-pin harness connector terminal No. 60 (Yellow wire). Right front HO2S 4-pin harness connector terminal "B" and PCM 104-pin harness connector terminal No. 91 (Brown wire). Left front HO2S 4-pin harness connector terminal "A" and PCM 104-pin harness connector terminal No. 87 (Green wire). Left front HO2S 4-pin harness connector terminal "B" and PCM 104-pin harness connector terminal No. 91 (Brown wire). Right rear HO2S 4-pin harness connector terminal "A" and PCM 104-pin harness connector terminal No. 35 (White wire). Right rear HO2S 4-pin harness connector terminal "B" and PCM 104-pin harness connector terminal No. 91 (Brown wire). Left rear HO2S 4-pin harness connector terminal "A" and PCM 104-pin harness connector terminal No. 61 (Red wire). Left rear HO2S 4-pin harness connector terminal "B" and PCM 104-pin harness connector terminal No. 91 (Brown wire). If continuity is present, go to next step. If continuity is not present, repair open circuit in suspect wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
3. Short Circuit Inspection Check for continuity between following: Right front HO2S 4-pin harness connector terminal "A" (Yellow wire) and power supply Right front HO2S 4-pin harness connector terminal "A" (Yellow wire) and ground. Right front HO2S 4-pin harness connector terminal "B" (Brown wire) and power supply. Left front HO2S 4-pin harness connector terminal "A" (Green wire) and power supply. Left front HO2S 4-pin harness connector terminal "A" (Green wire) and ground. Left front HO2S 4-pin harness connector terminal "B" (Brown wire) and power supply. Right rear HO2S 4-pin harness connector terminal "A" (White wire) and power supply. Right rear HO2S 4-pin harness connector terminal "A" (White wire) and ground. Right rear HO2S 4-pin harness connector terminal "B" (Brown wire) and power supply. Left rear HO2S 4-pin harness connector terminal "A" (Red wire) and power supply. Left rear HO2S 4-pin harness connector terminal "A" (Red wire) and ground. Left rear HO2S 4-pin harness connector terminal "B" (Brown wire) and power supply. If continuity is present, repair short circuit in suspect wire or replace wire harness.
4. HO2S Heater Resistance Inspection Disconnect negative battery cable. Disconnect HO2S 4-pin harness connector. Using DVOM, measure resistance between HO2S 4-pin connector terminals "C" and "D". HO2S heater resistance reading should be 3.0-3.6 ohms (front HO2Ss) 5.0-7.0 ohms (rear HO2Ss). If HO2S heater is okay, but PID value is out of specification, check for open or short circuit. Go to next step.
5. Open Circuit Inspection Disconnect PCM 104-pin harness connector. Check for continuity between following terminals: Right front HO2S 4-pin harness connector terminal "C" and ignition relay (Blue/Black wire). Right front HO2S 4-pin harness connector terminal "D" and PCM 104-pin harness connector terminal No. 93 (White/Black wire). Left front HO2S 4-pin harness connector terminal "C" and ignition relay (Blue/Black wire). Left front HO2S 4-pin harness connector terminal "D" and PCM 104-pin harness terminal 94 (White/Green wire). Right rear HO2S 4-pin harness connector terminal "C" and ignition relay (Blue/Black wire). Right rear HO2S 4-pin harness connector terminal "D" and PCM 104-pin harness connector terminal No. 95 (Yellow/Green wire). Left rear HO2S 4-pin harness connector terminal "C" and ignition relay (Blue/Black wire). Left rear HO2S 4-pin harness connector terminal "D" and PCM 104-pin harness connector terminal No. 96 (Violet wire). If continuity is present, go to next step. If continuity is not present, repair open circuit in suspect wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
6. Short Circuit Inspection Check for continuity between following: Right front HO2S 4-pin harness connector terminal "C" (Blue/Black wire) and body GND. Right front HO2S 4-pin harness connector terminal "D" (Violet wire) and power supply. Right front HO2S 4-pin harness connector terminal "D" (Violet wire) and body GND. Left front HO2S 4-pin harness connector terminal "C" (Blue/Black wire) and body GND. Left front HO2S 4-pin harness connector terminal "D" (Violet wire) and power supply. Left front HO2S 4-pin harness connector terminal "D" (Violet wire) and body GND. Right rear HO2S 4-pin harness connector terminal "C" (Blue/Black wire) and body GND. Right rear HO2S 4-pin harness connector terminal "D" (Violet wire) and power supply. Right rear HO2S 4-pin harness connector terminal "D" (Violet wire) and body GND. Left rear HO2S 4-pin harness connector terminal "C" (Blue/Black wire) and body GND. Left rear HO2S 4-pin harness connector terminal "D" (Violet wire) and power supply. Left rear HO2S 4-pin harness connector terminal "D" (Violet wire) and body GND. If continuity is present, repair short circuit in suspect wire or replace wire harness.

Scheme 159

1. Voltage Inspection Warm engine to normal operating temperature. Disconnect HO2S 4-pin harness connector. Connect voltmeter between ground and HO2S 4-pin connector terminal "A". (Scheme 160) Run engine at 3000 RPM until voltmeter indicates 0-1 volts. Ensure voltage changes within specification when engine RPM is increased or decreased several times. See «HO2S VOLTAGE SPECIFICATIONS»(ref-151892-S07817094092003010900000) table. If voltage reading does not change as specified, replace HO2S. If HO2S is okay but PID value is not as specified, go to next step.
2. Open Circuit Inspection Turn ignition off. Disconnect PCM 31-pin harness connector. (Scheme 161)and (Scheme 162). Check for continuity between following terminals: PCM 31-pin harness connector terminal No. 4W and front HO2S 4-pin harness connector terminal "A" (Blue wire). PCM 31-pin harness connector terminal No. 4O and front HO2S 4-pin harness connector terminal "B" (Black/Red wire), through common connector. PCM 31-pin harness connector terminal No. 4AA and rear HO2S 4-pin harness connector terminal "A" (Red wire). PCM 31-pin harness connector terminal No. 4O and rear HO2S 4-pin harness connector terminal "B" (Black/Red wire), through common connector. If continuity is present, go to next step. If continuity is not present, repair open circuit in suspect wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
3. Short Circuit Inspection Check for continuity between following terminals: PCM 31-pin harness connector terminal No. 4W (front HO2S) and HO2S 4-pin harness connector terminal "A" (Blue wire). PCM 31-pin harness connector terminal No. 4AA (rear HO2S) and HO2S 4-pin harness connector terminal "A" (Red wire). If continuity is present, repair short circuit in suspect wire or replace wire harness.
4. HO2S Heater Resistance Inspection Disconnect HO2S 4-pin harness connector. Using DVOM, measure resistance between HO2S 4-pin connector terminals "C" and "D". HO2S heater resistance reading should be about 5.6 ohms (front HO2S) or about 15.7 ohms (rear HO2S). If resistance reading is not as specified, replace suspect HO2S. If HO2S heater is okay, but PID value is out of specification, go to next step.
5. Open Circuit Inspection Check for continuity in following circuits: GND circuit - Between HO2S 4-pin harness connector "D" and PCM 24-pin harness connector terminal No. 3J (Black/Orange wire) through common connector (Front). Power circuit - Between HO2S 4-pin harness connector terminal "C" (Black/White wire) and ignition switch (IG1) circuit through common connector (Front). GND circuit - Between HO2S 4-pin harness connector terminal "D" (White/Black wire) and PCM 24-pin harness connector terminal No. 3P (Rear). Power circuit - Between HO2S 4-pin harness connector terminal "C" (Black/White wire) and ignition switch (IG1) circuit through common connector (Rear). If continuity is present, go to next step. If continuity is not present, repair open circuit in suspect wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
6. Short Circuit Inspection Check for continuity to ground in following circuits: HO2S 4-pin harness connector terminal "C" (Black/White wire) and ignition switch (IG1) through common connector (Front). HO2S 4-pin harness connector terminal "D" (Black/Orange wire) and PCM 24-pin harness connector terminal No. 3J through common connector (Front). HO2S 4-pin harness connector terminal "D" (White/Black wire) and PCM 24-pin harness connector terminal No. 3P (Rear). If continuity is present, repair short circuit to ground in appropriate wire or replace wire harness as necessary.

Scheme 160

Scheme 161

Scheme 162

1. Voltage Inspection Warm engine to normal operating temperature. Turn ignition off. Disconnect suspect HO2S connector. Connect voltmeter to HO2S terminals. See «HO2S TERMINAL IDENTIFICATION (MPV)»(ref-151892-S12045378912003010900000) table. Start engine. Raise engine speed to 3000 RPM until sensor voltage varies between zero and one volt. Allow engine to idle. Accelerate engine several times. Voltage reading should be.5-1.0 volt when accelerating, 0-.5 volt when decelerating. If HO2S sensor voltage reading is as specified but PID value or PCM voltages are not within specification, check for open or short circuit. Go to next step. If HO2S sensor voltage reading is not as specified, replace HO2S. HO2S TERMINAL IDENTIFICATION (MPV) Application Terminals Left Front A (+), B (-) Left Rear A (+), B (-) Right Front A (+), B (-) Right Rear A (+), B (-)
2. Open Circuit Inspection Disconnect PCM 104-pin harness connector. Connect 104-Pin Breakout Box (49-UN01-130) to PCM harness connector only. (Scheme 147) Check for continuity between following terminals: Right front HO2S harness connector terminal "A" and breakout box terminal No. 60 (Light Green/Red wire). Right front HO2S harness connector terminal "B" and breakout box terminal No. 91 (Brown/Yellow wire). Right rear HO2S harness connector terminal "A" and breakout box terminal No. 35 (Green wire). Right rear HO2S harness connector terminal "B" and breakout box terminal No. 91 (Blue/White wire). Left front HO2S harness connector terminal "A" and breakout box terminal No. 87 (White wire). Left front HO2S harness connector terminal "B" and breakout box terminal No. 91 (Brown/Yellow wire). Left rear HO2S harness connector terminal "A" and breakout box terminal No. 61 (Blue/White wire). Left rear HO2S harness connector terminal "B" and breakout box terminal No. 91 (Brown/Yellow wire). If continuity is present, go to next step. If continuity is not present, repair open circuit in suspect wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
3. Short Circuit Inspection Check for continuity between following terminals: Right front HO2S harness connector terminal "A" (Light Green/Red wire) and ground. Right front HO2S harness connector terminal "A" (Light Green/Red wire) and power. Right front HO2S harness connector terminal "B" (Brown/Yellow wire) and power. Right rear HO2S harness connector terminal "A" (Green wire) and ground Right rear HO2S harness connector terminal "A" (Green wire) and power. Right rear HO2S harness connector terminal "B" (Brown/Yellow wire) and power. Left front HO2S harness connector terminal "A" (White wire) and ground. Left front HO2S harness connector terminal "A" (White wire) and power. Left front HO2S harness connector terminal "B" (Brown/Yellow wire) and power. Left rear HO2S harness connector terminal "A" (Blue/White wire) and ground. Left rear HO2S harness connector terminal "A" (Blue/White wire) and power. Left rear HO2S harness connector terminal "B" (Brown/Yellow wire) and power. If continuity is not present, go to next step. If continuity is present, repair short circuit in suspect wire or replace wire harness.
4. HO2S Heater Resistance Inspection Allow sensor to cool to room temperature. Disconnect suspect HO2S connector. Using ohmmeter, measure resistance between HO2S connector terminals "C" and "D". Resistance reading should be 5.0-6.8 ohms (front HO2Ss) 14.1-18.9 ohms (rear HO2Ss). If resistance reading is not as specified, replace HO2S. If HO2S is okay but PID values are out of specification, check for open or short circuit. Go to next step.
5. Open Circuit Inspection Check for continuity between following terminals: Right front HO2S harness connector terminal "C" (Black/White wire) and power. Right front HO2S harness connector terminal "D" (Yellow wire) and breakout box terminal No. 93. Right rear HO2S harness connector terminal "C" (Black/White wire) and power. Right rear HO2S harness connector terminal "D" (Light Green wire) and breakout box terminal No. 95. Left front HO2S harness connector terminal "C" (Black/White wire) and power. Left front HO2S harness connector terminal "D" (Orange wire) and breakout box terminal No. 94. Left rear HO2S harness connector terminal "C" (Black/White wire) and power. Left rear HO2S harness connector terminal "D" (Green/Orange wire) and breakout box terminal No. 96. If continuity is present, go to next step. If continuity is not present, repair open circuit in suspect wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
6. Short Circuit Inspection Check for continuity between following: Right front HO2S harness connector terminal "C" (Black/White wire) and ground. Right front HO2S harness connector terminal "D" (Yellow wire) and ground. Right front HO2S harness connector terminal "D" (Yellow wire) and power. Right rear HO2S harness connector terminal "C" (Black/White wire) and ground. Right rear HO2S harness connector terminal "D" (Light Green wire) and ground. Right rear HO2S harness connector terminal "D" (Light Green wire) and power. Left front HO2S harness connector terminal "C" (Black/White wire) and ground. Left front HO2S harness connector terminal "D" (Orange wire) and ground. Left front HO2S harness connector terminal "D" (Orange wire) and power. Left rear HO2S harness connector terminal "C" (Black/White wire) and ground. Left rear HO2S harness connector terminal "D" (Green/Orange wire) and ground. Left rear HO2S harness connector terminal "D" (Green/Orange wire) and power. If continuity is present, repair short circuit in suspect wire or replace wire harness.

1. Voltage Inspection Warm engine to normal operating temperature. Allow engine to idle. Disconnect HO2S 4-pin harness connectors (front or rear). Connect analog voltmeter test leads to HO2S 4-pin connector terminals "A" and "B". Increase engine RPM to 3000 until voltmeter reads about 0.5-0.7 volt. Ensure voltmeter needle moves while increasing or decreasing engine speed suddenly several times. See «HO2S VOLTAGE SPECIFICATIONS»(ref-151892-S07817094092003010900000) table. If voltmeter needle moves, but PID value or PCM terminal No. 60 (front HO2S) or No. 35 (rear HO2S) voltage readings are out of specification, check for open or short circuit between PCM and HO2S. Go to next step. If voltmeter needle does not move with engine speed, replace HO2S.
2. Open Circuit Inspection Connect 104-Pin Breakout Box (49-UN01-130) between PCM and harness connector. (Scheme 147) Check for continuity between following terminals: HO2S 4-pin harness connector terminal "A" (Yellow/Blue wire) and breakout box terminal No. 35 (rear sensor). HO2S 4-pin harness connector terminal "A" (Pink/Blue wire) and breakout box terminal No. 60 (front sensor). HO2S 4-pin harness connector terminal "B" (Orange wire) and breakout box terminal No. 91. If continuity is present, go to next step. If continuity is not present, repair open circuit in suspect wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
3. Short Circuit Inspection Check for continuity between HO2S 4-pin harness connector terminal "A" and breakout box terminal No. 60 (front sensor) or No. 35 (rear sensor) to ground. If continuity is present, repair wiring or replace wire harness as necessary. If continuity is not present, go to next step.
4. HO2S Heater Resistance Inspection Allow sensor to cool to room temperature. Disconnect front or rear HO2S 4-pin harness connector. Measure resistance between front HO2S 4-pin connector terminals "C" and "D". (Scheme 158) Resistance reading should be about 5.6 ohms at 68°F (20°C). Measure resistance between rear HO2S 4-pin connector terminals "C" and "D". (Scheme 158) Resistance reading should be about 15.7 ohms. If resistance reading is not as specified, replace appropriate HO2S. If resistance reading is as specified but PID value or PCM terminal No. 93 or 94 voltage is out of specification, check for open or short circuit. Go to next step.
5. Open Circuit Inspection Connect 104-Pin Breakout Box (49-UN01-130) between PCM and PCM 104-pin harness connector. (Scheme 147) Check for continuity between following terminals: HO2S 4-pin harness connector terminal "C" and ignition switch terminal "IG1" (Blue wire) through common connector. (Scheme 163) HO2S 4-pin harness connector terminal "D" (Green/Red wire) and breakout box terminal No. 93 (rear sensor). HO2S 4-pin harness connector terminal "D" (Light Green/Red wire) and breakout box terminal No. 94 (front sensor). If continuity is present, go to next step. If continuity is not present, repair open circuit in suspect wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
6. Short Circuit Inspection Check for continuity between ground and following circuits: HO2S 4-pin harness connector terminal "C" and ignition switch terminal "IG1" (Blue wire) through common connector to ground. (Scheme 163) HO2S 4-pin harness connector terminal "D" (Green/Red wire) and breakout box terminal No. 93 (rear sensor) to ground. HO2S 4-pin harness connector terminal "D" (Light Green/Red wire) and breakout box terminal No. 94 (front sensor) to ground. If continuity is present, repair or replace wire harness as necessary. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS. If short circuit is not present, replace suspect HO2S.

Scheme 163

INTAKE AIR TEMPERATURE SENSOR

Note. On Mazda6 and MPV, Intake Air temperature (IAT) sensor is part of Mass Airflow (MAF) sensor.

1. Resistance Inspection Disconnect MAF/IAT sensor 5-pin harness connector. (Scheme 164) Using DVOM, measure resistance between MAF/IAT sensor 5-pin connector terminals "D" and "E". See «MAF/IAT SENSOR RESISTANCE SPECIFICATIONS (MAZDA6 & MPV)»(ref-151892-S08594729532003010900000) table. If MAF/IAT sensor is okay, check for open or short circuit. Go to next step. If resistance readings are not as specified, replace MAF/IAT sensor.
2. Open Circuit Inspection Check for continuity between following terminals: MAF/IAT sensor 5-pin harness connector terminal "D" and PCM 30-pin harness connector terminal No. 2E (Blue/Black wire). (Scheme 165) MAF/IAT sensor 5-pin harness connector terminal "E" and PCM 30-pin harness connector terminal No. 2H (Brown wire). If continuity is present, go to next step. If continuity is not present, repair open circuit in suspect wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
3. Short Circuit Inspection Check for continuity between following: MAF/IAT sensor 5-pin harness connector terminal "E" (Brown wire) and power supply. MAF/IAT sensor 5-pin harness connector terminal "D" (Blue/Black wire) and power supply. MAF/IAT sensor 5-pin harness connector terminal "D" (Blue/Black wire) and ground.

If continuity is present, repair short circuit in suspect wire or replace wire harness.

Scheme 164

Scheme 165

1. Resistance Inspection Disconnect MAF/IAT sensor 5-pin harness connector. (Scheme 164) Using DVOM, measure resistance between MAF/IAT sensor 5-pin connector terminals "D" and "E". See «MAF/IAT SENSOR RESISTANCE SPECIFICATIONS (MAZDA6 & MPV)»(ref-151892-S08594729532003010900000) table. If MAF/IAT sensor is okay, check for open or short circuit. Go to next step. If resistance readings are not as specified, replace MAF/IAT sensor.
2. Open Circuit Inspection Check for continuity between following terminals: MAF/IAT sensor 5-pin harness connector terminal "D" and PCM 104-pin harness connector terminal No. 39 (Blue/Black wire). (Scheme 165) MAF/IAT sensor 5-pin harness connector terminal "E" and PCM 104-pin harness connector terminal No. 91 (Brown wire). If continuity is present, go to next step. If continuity is not present, repair open circuit in suspect wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
3. Short Circuit Inspection Check for continuity between following: MAF/IAT sensor 5-pin harness connector terminal "E" (Brown wire) and power supply. MAF/IAT sensor 5-pin harness connector terminal "D" (Blue/Black wire) and power supply. MAF/IAT sensor 5-pin harness connector terminal "D" (Blue/Black wire) and ground.

If continuity is present, repair short circuit in suspect wire or replace wire harness.

1. Resistance Inspection Disconnect Intake Air Temperature (IAT) sensor 2-pin harness connector. (Scheme 166) Remove IAT sensor. Using DVOM, measure resistance between IAT sensor connector terminals "A" and "B". See «IAT SENSOR RESISTANCE SPECIFICATIONS (EXCEPT MAZDA6 & MPV)»(ref-151892-S02671496452003010900000) table. If resistance readings are as specified, check for open or short circuit. Go to next step. If resistance readings are not as specified, replace IAT sensor.
2. Open Circuit Inspection Check for continuity between following terminals: IAT sensor harness connector terminal "B" and PCM 31-pin harness connector terminal No. 4N (Pink/Blue wire). IAT sensor harness connector terminal "A" and PCM 31-pin harness connector terminal No. 4O (Black/Red wire). If continuity is present, go to next step. If continuity is not present, repair open circuit in suspect wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
3. Short Circuit Inspection Check for continuity to ground in Pink/Blue wire between IAT sensor harness connector terminal "B" and PCM 31-pin harness connector terminal No. 4N. If continuity is present, repair short circuit to ground in Pink/Blue wire between IAT sensor harness connector terminal "B" and PCM 31-pin harness connector terminal No. 4N.

IAT SENSOR RESISTANCE SPECIFICATIONS (EXCEPT MAZDA6 & MPV)

Scheme 166

1. Resistance Inspection Disconnect MAF/IAT sensor 6-pin harness connector. (Scheme 167) Using ohmmeter, measure resistance between MAF/IAT sensor terminals "A" and "F", located at each end of connector. See «MAF/IAT SENSOR RESISTANCE SPECIFICATIONS (MAZDA6 & MPV)»(ref-151892-S08594729532003010900000) table. If resistance readings are not as specified, replace MAF/IAT sensor. If IAT sensor is within specification but PID value is out of specification, check for open or short circuit. Go to next step. MAF/IAT SENSOR RESISTANCE (MAZDA6 & MPV) Temperature - °F (°C) Ohms MAZDA6 -4 (-20) 13,600-18,400 68 (20) 2210-2690 140 (60) 493-667 MPV 50 (10) 3300-4100 68 (20) 2200-2700 86 (30) 1400-1900
2. Open Circuit Inspection Disconnect PCM 104-pin harness connector. Connect 104-Pin Breakout Box (49-UN01-130) to PCM harness connector only. (Scheme 147) Check for continuity between following terminals: MAF/IAT sensor 6-pin harness connector terminal "A" (Brown/Yellow wire) and breakout box terminal No. 91. MAF/IAT sensor 6-pin harness connector terminal "F" (Violet wire) and breakout box terminal No. 39. If continuity is present, go to next step. If continuity is not present, repair open circuit in suspect wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
3. Short Circuit Inspection Check for continuity between following: MAF/IAT sensor 6-pin harness connector terminal "A" (Brown/Yellow wire) and power supply MAF/IAT sensor 6-pin harness connector terminal "F" (Violet wire) and power supply. MAF/IAT sensor 6-pin harness connector terminal "F" (Violet wire) and ground. If continuity is present, repair short circuit in suspect wire or replace wire harness.

Scheme 167

1. Resistance Inspection Disconnect Intake Air Temperature (IAT) sensor 2-pin harness connector. (Scheme 166) Remove IAT sensor. Using DVOM, measure resistance between IAT sensor terminals "A" and "B". See «IAT SENSOR RESISTANCE SPECIFICATIONS (EXCEPT MPV)»(ref-151892-S02671496452003010900000) table. If resistance readings are as specified, go to next step. If resistance readings are not as specified, replace IAT sensor.
2. Open Circuit Inspection Disconnect PCM 104-pin harness connector. Connect 104-Pin Breakout Box (49-UN01-130) to PCM harness connector only. (Scheme 147) Check for continuity between following terminals: IAT sensor harness connector terminal "A" (Blue/White wire) and breakout box terminal No. 39. IAT sensor harness connector terminal "B" (Orange wire) and breakout box terminal No. 91. If continuity is present, go to next step. If continuity is not present, repair open circuit in suspect wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
3. Short Circuit Inspection Check for continuity to ground in Blue/White wire between IAT sensor harness connector terminal "A" and PCM 104-pin harness connector terminal No. 39. If continuity is present, repair short circuit to ground in Blue/White wire between IAT sensor harness connector terminal "A" and PCM 104-pin harness connector terminal No. 39 or replace wire harness.

1. Resistance Inspection Disconnect Knock Sensor (KS) 2-pin harness connector. Using DVOM, measure resistance between KS terminals "A" and "B". Resistance reading should be about 4.87 megohms at 68°F (20°C). If resistance reading is not as specified, replace KS. If KS resistance reading is within specification, check for open or short circuit in wiring harness. Go to next step.
2. Open Circuit Inspection Disconnect PCM 30-pin harness connector. Check for continuity between following terminals: KS harness connector terminal "A" (Yellow wire) and PCM 30-pin harness connector terminal No. 2S. KS harness connector terminal "B" (Brown wire) and PCM 30-pin harness connector terminal No. 2P. If continuity is present, go to next step. If continuity is not present, repair open circuit in suspect wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
3. Short Circuit Inspection Check for continuity between following: KS harness connector terminal "A" (Yellow wire) and power supply. KS harness connector terminal "B" (Brown wire) and ground. KS harness connector terminal "A" (Yellow wire) and ground. KS harness connector terminal "B" (Brown wire) and power supply. If continuity is present, repair short circuit in suspect wire or replace wire harness.

1. Resistance Inspection Disconnect Knock Sensor (KS) 2-pin harness connector. Using ohmmeter, measure resistance between KS terminals "A" and "B". Resistance should be about 4.87 megohms at 68°F (20°C). If KS resistance reading is within specification, check for open or short circuit. Go to next step. If resistance reading is not as specified, replace KS.
2. Open Circuit Inspection Disconnect PCM 104-pin harness connector. Check for continuity between following terminals: KS harness connector terminal "A" (Green wire) and PCM 104-pin harness connector terminal No. 4. KS harness connector terminal "B" (Red wire) and PCM 104-pin harness connector terminal No. 31. If continuity is present, go to next step. If continuity is not present, repair open circuit in suspect wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
3. Short Circuit Inspection Check for continuity between following: KS harness connector terminal "A" (Green wire) and power supply. KS harness connector terminal "B" (Red wire) and ground. KS harness connector terminal "A" (Green wire) and ground. KS harness connector terminal "B" (Red wire) and power supply. If continuity is present, repair short circuit in suspect wire or replace wire harness.

1. Resistance Inspection Disconnect Knock Sensor (KS) 2-pin harness connector. (Scheme 168) Using DVOM, measure resistance between KS terminal "A" and KS body. Resistance reading should be about 560,000 ohms at 68°F (20°C). If resistance reading is not as specified, replace KS. If KS resistance reading is within specification, check for open or short circuit in wiring harness. Go to next step.
2. Open Circuit Inspection Disconnect PCM 31-pin harness connector. Check for continuity between KS harness connector terminal "A" (White wire) and PCM 31-pin harness connector terminal No. 4M through common connector. If continuity is present, go to next step. If continuity is not present, repair open circuit in White wire between KS harness connector and PCM 31-pin harness connector terminal No. 4M or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
3. Short Circuit Inspection Check for continuity to ground between KS harness connector terminal "A" (White wire) and PCM 31-pin harness connector terminal No. 4M. If continuity is present, repair short circuit to ground in White wire between KS harness connector terminal "A" and PCM 31-pin harness connector terminal No. 4M or replace wire harness.

Scheme 168

1. Resistance Inspection Disconnect Knock Sensor (KS) 2-pin harness connector. Using ohmmeter, measure resistance between KS terminals "A" and "B". Resistance should be about 560,000 ohms at 68°F (20°C). If resistance is not as specified, replace KS. If KS is within specification, go to next step.
2. Open Circuit Inspection Disconnect PCM 104-pin harness connector. Connect 104-Pin Breakout Box (49-UN01-130) to PCM harness connector only. (Scheme 147) Check for continuity between following terminals: KS harness connector terminal "A" (Blue/White wire) and breakout box terminal No. 57. KS harness connector terminal "B" (Red/White wire) and breakout box terminal No. 4. If continuity is present, go to next step. If continuity is not present, repair open circuit in suspect wire or replace wire harness.
3. Short Circuit Inspection Check for continuity between following: KS harness connector terminal "A" (Blue/White wire) and power supply. KS harness connector terminal "B" (Red/White wire) and power supply. KS harness connector terminals "A" (Blue/White wire) and ground. KS harness connector terminals "B" (Red/White wire) and ground. If continuity is present, repair short circuit in suspect wire or replace wire harness.

1. Resistance Inspection Disconnect Knock Sensor (KS) 2-pin harness connector. Using DVOM, measure resistance between KS terminals "A" and "B". Resistance should be about 560,000 ohms at 68°F (20°C). If resistance reading is as specified, go to next step. If resistance is not as specified, replace KS.
2. Open Circuit Inspection Disconnect PCM 104-pin harness connector and install 104-Pin Breakout Box (49-UN01-130) to PCM harness connector only. (Scheme 147) Check for continuity between following terminals: KS harness connector terminal "A" (Yellow/Blue wire) and breakout box terminal No. 57. KS harness connector terminal "B" (Red wire) and breakout box terminal No. 59. If continuity is present, go to next step. If continuity is not present, repair open circuit in suspect wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
3. Short Circuit Inspection Check for continuity to ground between following terminals: KS harness connector terminal "A" (Yellow/Blue wire) and breakout box terminal No. 57 KS harness connector terminal "B" (Red wire) and breakout box terminal No. 59. If continuity is present, repair short circuit to ground in suspect wire or replace wire harness.

1. Connected scan tool to DLC-2. Turn ignition on, engine off. Select MAP PID. Verify MAP PID and barometric pressure are practically equal. If as verified, go to next step. If not as verified, check for open or short circuit. Go to step 3.
2. Apply vacuum of -7.38 in. Hg to MAP sensor, and verify MAP variation from that of step 1 is about 7.38 in. Hg. If not as verified, check for open or short circuit. Go to next step.
3. Open Circuit Inspection Disconnect Manifold Absolute Pressure (MAP) sensor 4-pin harness connector. (Scheme 169) Disconnect PCM harness connectors. Check for continuity between following terminals: MAP sensor 4-pin harness connector terminal "A" and PCM 30-pin harness connector terminal No. 2H (Brown wire). MAP sensor 4-pin harness connector terminal "C" and PCM 30-pin harness connector terminal No. 2K (Red/Black wire). MAP sensor 4-pin harness connector terminal "D" and PCM 30-pin harness connector terminal No. 1J (Yellow/Black wire). If continuity is present, go to next step. If continuity is not present, repair open circuit in suspect wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
4. Short Circuit Inspection Check for continuity between following: MAP sensor 4-pin harness connector terminal "C" (Red/Black wire) and power supply. MAP sensor 4-pin harness connector terminal "C" (Red/Black wire) and ground. MAP sensor 4-pin harness connector terminal "D" (Yellow/Black wire) and power supply. MAP sensor 4-pin harness connector terminal "D" (Yellow/Black wire) and ground. If continuity is present, repair short circuit to ground in suspect wire or replace wire harness. If open or short circuit is not present, replace MAP sensor.

Scheme 169

MASS AIRFLOW SENSOR

Note. On Mazda6 and MPV, Intake Air temperature (IAT) sensor is part of Mass Airflow (MAF) sensor.

1. Visually check Mass Airflow/Intake Air Temperature (MAF/IAT) sensor for cracks, bent or corroded terminals, or damage. If any fault is present, replace MAF/IAT sensor. If MAF/IAT sensor is okay, connect scan tool to DLC-2. Access MAF PID. See «MAF/IAT SENSOR SPECIFICATIONS (A/T)»(ref-151892-S02201635092003051700000) or «MAF/IAT SENSOR SPECIFICATIONS (M/T)»(ref-151892-S34841835452003051900000) . If MAF PID value is not as specified, check for open or short circuit. Go to next step.
2. Open Circuit Inspection Disconnect PCM 30-pin harness connectors and MAF/IAT sensor 5-pin harness connector. Check for continuity between following terminals: MAF/IAT sensor 5-pin harness connector terminal "A" and main relay 4-pin harness connector terminal "C" (White wire). MAF/IAT sensor 5-pin harness connector terminal "B" and PCM 30-pin harness connector terminal No. 2AC (Gray wire). MAF/IAT sensor 5-pin harness connector terminal "C" and PCM 30-pin harness connector terminal No. 1P (Gray/Black wire). If continuity is present, go to next step. If continuity is not present, repair open circuit in suspect wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
3. Short Circuit Inspection Check for continuity between following: MAF/IAT sensor 5-pin harness connector terminal "A" (White wire) and ground. MAF/IAT sensor 5-pin harness connector terminal "C" (Gray/Black wire) and power supply. MAF/IAT sensor 5-pin harness connector terminal "C" (Gray/Black wire) and ground. MAF/IAT sensor 5-pin harness connector terminal "B" (Gray wire) and power supply. If continuity is present, repair short circuit to ground in suspect wire or replace wire harness.

MAF/IAT SENSOR SPECIFICATIONS (A/T)

MAF/IAT SENSOR SPECIFICATIONS (M/T)

1. Visually check Mass Airflow/Intake Air Temperature (MAF/IAT) sensor for cracks, bent or corroded terminals, or damage. If any fault is present, replace MAF/IAT sensor. If MAF/IAT sensor is okay, connect scan tool to DLC-2. Access MAF PID. See «MAF/IAT SENSOR SPECIFICATIONS (A/T)»(ref-151892-S02201635092003051700000) or «MAF/IAT SENSOR SPECIFICATIONS (M/T)»(ref-151892-S34841835452003051900000) . If MAF PID value is not as specified, check for open or short circuit. Go to next step.
2. Open Circuit Inspection Disconnect PCM 104-pin harness connector and MAF/IAT sensor 5-pin harness connector. Check for continuity between following terminals: MAF/IAT sensor 5-pin harness connector terminal "A" and main relay 4-pin harness connector terminal "C" (White wire). MAF/IAT sensor 5-pin harness connector terminal "B" and PCM 104-pin harness connector terminal No. 77 (Gray wire). MAF/IAT sensor 5-pin harness connector terminal "C" and PCM 104-pin harness connector terminal No. 88 (Gray/Black wire). If continuity is present, go to next step. If continuity is not present, repair open circuit in suspect wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
3. Short Circuit Inspection Check for continuity between following: MAF/IAT sensor 5-pin harness connector terminal "A" (White wire) and body GND. MAF/IAT sensor 5-pin harness connector terminal "B" (Gray wire) and power supply. MAF/IAT sensor 5-pin harness connector terminal "C" (Gray/Black wire) and power supply. MAF/IAT sensor 5-pin harness connector terminal "C" (Gray/Black wire) and body GND. If continuity is present, repair short circuit to ground in suspect wire or replace wire harness.

1. Visually check Mass Airflow (MAF) sensor for cracks or damage. If any damage is present, replace MAF sensor. If MAF sensor is okay, go to next step.
2. Voltage Inspection Turn ignition on. Using DVOM, measure voltage at PCM 31-pin harness connector terminal No. 4X (Pink wire). (Scheme 147) See «MAF SENSOR VOLTAGE SPECIFICATIONS»(ref-151892-S19807789032003010900000) table. If voltage reading is not as specified, check for open or short circuit
3. Open Circuit Inspection Disconnect PCM 31-pin harness connector. Check for continuity between following terminals: MAF circuit - MAF sensor 3-pin harness connector terminal "B" and PCM 31-pin harness connector terminal No. 4X. Power circuit - MAF sensor 3-pin harness connector terminal "C" and main relay 4-pin harness connector terminal "D" through common connector. GND circuit - MAF sensor 3-pin harness connector terminal "A" and PCM 31-pin harness connector terminal No. 4A through common connector. If continuity is present, go to next step. If continuity is not present, repair open circuit in suspect wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
4. Short Circuit Inspection Check for continuity between following: MAF sensor 3-pin harness connector terminal "B" and PCM 31-pin harness connector terminal No. 4X (Pink wire) to ground. MAF sensor 3-pin harness connector terminal "C" and main relay 4-pin harness connector terminal "D" (White/Red wire) to ground. If continuity is present, repair short circuit in suspect wire or replace wire harness. If open or short circuit is not present, replace MAF sensor.

MAF SENSOR VOLTAGE SPECIFICATIONS

1. Voltage Inspection Disconnect PCM 104-pin harness connector. Connect 104-Pin Breakout Box (49-UN01-130) to PCM harness connector only. (Scheme 147) Turn ignition on, engine off. Measure voltage between breakout box terminals No. 36 and 88. See «MAF SENSOR VOLTAGE SPECIFICATIONS»(ref-151892-S19807789032003010900000) table. If voltage reading is as specified, go to next step. If voltage reading is not as specified, go to step 3.
2. Start engine and warm up completely. Measure voltage between breakout box terminals No. 36 and 88. See «MAF SENSOR VOLTAGE SPECIFICATIONS»(ref-151892-S19807789032003010900000) table. If voltage reading is not as specified, go to next step.
3. Open Circuit Inspection Using DVOM, check for continuity between following terminals: MAF/IAT sensor 6-pin harness connector terminal "B" and main relay 4-pin harness connector terminal "C" (White/Red wire). MAF/IAT sensor 6-pin harness connector terminal "D" and 104-pin breakout box terminal No. 36 (Gray wire). MAF/IAT sensor 6-pin harness connector terminal "E" and 104-pin breakout box terminal No. 88 (Blue/White wire). If continuity is present, go to next step. If continuity is not present, repair open circuit in suspect wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
4. Short Circuit Inspection Check for continuity between following: MAF/IAT sensor 6-pin harness connector terminal "B" (White/red wire) and ground. MAF/IAT sensor 6-pin harness connector terminal "D" (Gray wire) and power supply. MAF/IAT sensor 6-pin harness connector terminal "E" (Blue/White wire) and power supply. MAF/IAT sensor 6-pin harness connector terminal "E" (Blue/White wire) and ground. If continuity is present, repair short circuit in suspect wire or replace wire harness.

1. Visually check Mass Airflow (MAF) sensor for cracks or damage. If any damage is present, replace MAF sensor. If MAF sensor is okay but PID values or PCM terminal voltage is out of specification, check for open or short circuit. See «MAF SENSOR VOLTAGE SPECIFICATIONS»(ref-151892-S19807789032003010900000). Go to next step.
2. Open Circuit Inspection Disconnect PCM 104-pin harness connector. Connect 104-Pin Breakout Box (49-UN01-130) to PCM harness connector only. (Scheme 147) Check for continuity between following terminals: MAF signal circuit - MAF sensor 3-pin harness connector terminal "B" (Light Green/Black wire) and breakout box terminal No. 88. Power circuit - MAF sensor 3-pin harness connector terminal "C" and main relay 4-pin harness connector terminal "D" (through common connector). GND circuit - MAF sensor 3-pin harness connector terminal "A" and breakout box terminal No. 103 through common connector. If continuity is present, go to next step. If continuity is not present, repair open circuit in appropriate wire or replace wire harness as necessary. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
3. Short Circuit Inspection Check continuity between following terminals: MAF signal circuit - MAF sensor 3-pin harness connector terminal "B" and breakout box terminal No. 88 to ground. Power circuit - MAF sensor 3-pin harness connector terminal "C" and main relay 4-pin harness connector terminal "D" through common connector to ground. If continuity is present, repair short circuit to ground in appropriate wire or replace wire harness. If open or short circuit is not present, replace MAF sensor.

1. Continuity Inspection Disconnect negative battery cable. Disconnect neutral switch 2-pin harness connector. Check for continuity between neutral switch terminals. Continuity should be present when neutral switch rod is pushed. Continuity should not be present when neutral switch rod is released. If neutral switch is okay but PID value is out of specification, go to next step. If continuity is not as specified, replace neutral switch.
2. Open Circuit Inspection Disconnect PCM harness connectors. Check for continuity between following terminals: Neutral switch harness connector terminal "B" and PCM 30-pin harness connector terminal No. 1W (Blue/Red wire). Neutral switch harness connector terminal "A" (Black wire) and ground. If continuity is present, go to next step. If continuity is not present, repair open circuit in suspect wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
3. Short Circuit Inspection Check for continuity between ground and neutral switch harness connector terminal "B" (Black wire). If continuity is present, repair short circuit in Black wire or replace wire harness.

1. Continuity Inspection Disconnect negative battery cable. Disconnect neutral switch 2-pin harness connector. Check for continuity between neutral switch terminals. Continuity should be present when neutral switch rod is pushed. Continuity should not be present when neutral switch rod is released. If neutral switch is okay but PID value is out of specification, go to next step. If continuity is not as specified, replace neutral switch.
2. Open Circuit Inspection Disconnect PCM 104-pin harness connector. Check for continuity between following terminals: Neutral switch harness connector terminal "B" and PCM 104-pin harness connector terminal No. 64 (Blue/Red wire) through common connector. Neutral switch harness connector terminal "A" (Black wire) and ground through common connector. If continuity is present, go to next step. If continuity is not present, repair open circuit in suspect wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
3. Short Circuit Inspection Check for continuity between ground and neutral switch harness connector terminal "B" (Black wire). If continuity is present, repair short circuit in Black wire or replace wire harness.

1. Continuity Inspection Disconnect neutral switch 2-pin harness connectors. Using ohmmeter, check continuity between neutral switch terminals. Ensure continuity is present with transmission in neutral (button on switch is pushed) and is not present in any other gear. If continuity is not present, go to next step. If neutral switch operation is not as specified, replace neutral switch.
2. Open Circuit Inspection Disconnect PCM 31-pin harness connector. Check for continuity between following: Power circuit - Neutral switch harness connector terminal "A" (Violet wire) and PCM 31-pin harness connector terminal No. 4H (through common connector). GND circuit - Neutral switch harness connector terminal "B" (Black wire) and ground (through common connector). If continuity is present, go to next step. If continuity is not present, repair open circuit in suspect wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
3. Short Circuit Inspection Check continuity in signal circuit between neutral switch harness connector terminal "A" (Violet wire) and PCM 31-pin harness connector terminal No. 64 (through common connector). If continuity is present, repair short circuit to ground in Violet wire between neutral switch harness connector terminal "A" and PCM 104-pin harness connector terminal No. 64.

If there is no open or short circuit present, replace neutral switch.

1. Continuity Inspection Disconnect neutral switch 2-pin harness connectors. Using ohmmeter, check continuity between neutral switch terminals. Ensure continuity is present with transmission in neutral (button on switch is pushed) and is not present in any other gear. If continuity is not present, go to next step. If neutral switch operation is not as specified, replace neutral switch.
2. Open Circuit Inspection Disconnect PCM 104-pin harness connector. Connect 104-Pin Breakout Box (49-UN01-130) to PCM harness connector only. (Scheme 147) Check for continuity between following terminals: Power circuit - Neutral switch harness connector terminal "A" (Pink/Green wire) and breakout box terminal No. 64 (through common connector). GND circuit - Neutral switch harness connector terminal "B" (Black wire) and ground (through common connector). If continuity is present, go to next step. If continuity is not present, repair open circuit in suspect wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
3. Short Circuit Inspection Check continuity in Signal circuit between neutral switch harness connector terminal "A" (Pink/Green wire) and breakout box terminal No. 64 (through common connector). If continuity is present, repair short circuit to ground in Pink/Green wire between neutral switch harness connector terminal "A" and PCM 104-pin harness connector terminal No. 64.

If there is no open or short circuit present, replace neutral switch.

POWER STEERING PRESSURE SWITCH

Note. Ensure power steering fluid level is correct.

1. Continuity Inspection Disconnect Power Steering Pressure (PSP) switch single pin harness connector. Connect ohmmeter between PSP switch terminal and ground. Start engine and operate at idle. Turn steering wheel from side to side and observe ohmmeter. Continuity should be present when steering wheel is turned. Continuity should not be present when steering wheel is in straight ahead position. If continuity is as specified, go to next step. If continuity is not as specified, replace PSP switch.
2. Open Circuit Inspection Disconnect PCM 30-pin harness connectors. Check for continuity in Black/Blue wire between PSP switch harness connector terminal and PCM 30-pin harness connector terminal No. 1Z. If continuity is present, go to next step. If continuity is not present, repair open circuit in Black/Blue wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
3. Short Circuit Inspection Check for continuity in Black/Blue wire between PSP switch harness connector terminal and ground. If continuity is present, repair short to ground in Black/Blue wire between PSP switch harness connector terminal and PCM 30-pin harness connector terminal No. 1Z.

1. Continuity Inspection Disconnect Power Steering Pressure (PSP) switch single pin harness connector. Connect ohmmeter between PSP switch terminal and ground. Start engine and operate at idle. Turn steering wheel from side to side and observe ohmmeter. Continuity should be present when steering wheel is turned. Continuity should not be present when steering wheel is in straight ahead position. If continuity is as specified, go to next step. If continuity is not as specified, replace PSP switch.
2. Open Circuit Inspection Disconnect PCM 104-pin harness connector. Check for continuity between PSP switch harness connector terminal (Brown/Green wire) and PCM 104-pin harness connector terminal No. 14 (Black/Blue wire). If continuity is present, go to next step. If continuity is not present, repair open circuit between PSP switch harness connector terminal (Brown/Green wire) and PCM 104-pin harness connector terminal No. 14 (Black/Blue wire) through common connector. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
3. Short Circuit Inspection Check for continuity between following: PSP switch harness connector terminal and power supply. PSP switch harness connector terminal and ground. If continuity is present, repair short circuit between PSP switch terminal (Brown/Green wire) and PCM 104-pin harness connector terminal No. 14 (Black/Blue wire) through common connector.

1. Continuity Inspection Disconnect Power Steering Pressure (PSP) switch single pin harness connector. Connect ohmmeter between PSP switch terminal and ground. Start engine and operate at idle. Turn steering wheel from side to side and observe ohmmeter. Continuity should be present when steering wheel is turned. Continuity should not be present when steering wheel is in straight ahead position. If continuity is not as specified, replace PSP switch.
2. Open Circuit Inspection Check for continuity in following circuits: Power circuit - PSP switch harness connector terminal (Brown wire) and PCM 31-pin harness connector terminal No. 4C. GND circuit - PSP switch body and ground. If continuity is present, go to next step. If continuity is not present, repair open circuit in Brown wire between PSP switch harness connector and PCM 31-pin harness connector terminal No. 4C. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
3. Short Circuit Inspection Check for continuity in Brown wire between PSP switch harness connector terminal and PCM 31-pin harness connector terminal No. 4C to ground. If continuity is present, repair short circuit to ground in Brown wire between PSP switch harness connector and PCM 31-pin harness connector terminal No. 4C.

1. Continuity Inspection Disconnect Power Steering Pressure (PSP) switch single pin harness connector. Connect ohmmeter between PSP switch terminal and ground. Start engine and operate at idle. Turn steering wheel from side to side and observe ohmmeter. Continuity should be present when steering wheel is turned. Continuity should not be present when steering wheel is straight ahead position. If PSP switch is okay, go to next step. If continuity is not as specified, replace PSP switch.
2. Open Circuit Inspection Check for continuity in Black/Blue wire between PSP switch harness connector terminal and PCM 104-pin harness connector terminal No. 31. If continuity is present, go to next step. If continuity is not present, repair open circuit in Black/Blue wire between PSP switch harness connector and PCM 104-pin harness connector terminal No. 31. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
3. Short Circuit Inspection Check for continuity in Black/white wire between PSP switch harness connector terminal and PCM 104-pin harness connector terminal No. 31 to ground. If continuity is present, repair short circuit to ground in Black/Blue wire between PSP switch harness connector and PCM 104-pin harness connector terminal No. 31.

1. Continuity Inspection Disconnect Power Steering Pressure (PSP) switch single pin harness connector. Connect ohmmeter between PSP switch terminal and ground. Start engine and operate at idle. Turn steering wheel from side to side and observe ohmmeter. Continuity should be present when steering wheel is turned. Continuity should not be present when steering wheel is straight ahead position. If continuity is not as specified, replace PSP switch.
2. Open Circuit Inspection Check for continuity in following circuits: Power circuit - PSP switch harness connector terminal (Black/White wire) and PCM 104-pin harness connector terminal No. 31. GND circuit - PSP switch body and ground. If continuity is present, go to next step. If continuity is not present, repair open circuit in Black/White wire between PSP switch harness connector and PCM 104-pin harness connector terminal No. 31. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
3. Short Circuit Inspection Check for continuity in Black/white wire between PSP switch harness connector terminal and PCM 104-pin harness connector terminal No. 31 to ground. If continuity is present, repair short circuit to ground in Black/White wire between PSP switch harness connector and PCM 104-pin harness connector terminal No. 31.

TRANSAXLE/TRANSMISSION RANGE SWITCH

1. Check for starter operation with ignition switch in START position and shift lever in "P" and "N" position only. Ensure back-up lights illuminate with ignition in "ON" position and selector lever in "R" position.
2. To test switch, disconnect Transaxle/Transmission Range (TR) switch harness connector. Check for continuity between specified terminals at TR switch. (Scheme 170), (Scheme 171), (Scheme 172), (Scheme 173), (Scheme 174) or (Scheme 175). If continuity is not as specified, replace TR switch. On Mazda6 2.3L only, if TR switch is okay, go to next step.
3. Recheck TR switch resistance. Measure resistance between TR switch terminals "B" and "C". (Scheme 170) If resistance readings are not as specified, replace TR switch.

Scheme 170

Scheme 171

Scheme 172

Scheme 173

Scheme 174

Scheme 175

VEHICLE SPEED SENSOR

Note. For MAZDA6 & MPV with Anti-lock Brake System (ABS), see wheel speed diagnosis in appropriate ANTI-LOCK article in BRAKES.

MAZDA6 (Without ABS) & Miata (M/T)

Vehicle Speed Sensor (VSS) is located on side of transmission. Disconnect negative battery cable. Disconnect VSS harness connector. Remove VSS. Using analog voltmeter, measure voltage between sensor terminals while rotating gear on VSS. Voltmeter needle should fluctuate between zero and 5 volts. (Scheme 176) If voltmeter needle does not fluctuate, replace VSS.

Scheme 176

Miata A/T

VSS is located on side of transaxle/transmission. Disconnect VSS connector. Measure resistance between sensor terminals. See VSS SPECIFICATIONS (MIATA A/T & MPV WITHOUT ABS) table. If resistance reading is not as specified, replace sensor. If resistance reading is as specified, repair or replace wiring harness.

VSS SPECIFICATIONS (MIATA A/T & MPV WITHOUT ABS)

MPV (Without ABS)

Note. VSS is mounted internally in transaxle. Information for replacement of sensor is not available from manufacturer.

Disconnect transaxle connector No. 2 (8-pin). (Scheme 177)and (Scheme 178). Measure resistance between terminals "A" and "B" on transaxle side of connector No. 2. See VSS SPECIFICATIONS (MIATA A/T & MPV WITHOUT ABS) table. If resistance is not within specification, replace VSS.

Scheme 177

Scheme 178

1. Visual Inspection Remove Vehicle Speed Sensor (VSS). Clean off any particles or metal shavings from sensor. Reinstall VSS.
2. Wave Profile Inspection Remove PCM. Connect 104-Pin Breakout Box (49-UN01-130) to PCM harness connector and PCM. (Scheme 147) Connect scan tool to DLC-2. Connect oscilloscope test leads to following breakout box terminals: Positive test lead - breakout box terminal No. 58. Negative test lead - breakout box terminal No. 103. Start engine. Monitor VSS PID. With oscilloscope settings at 1 V/DIV (Y), 2.5 ms/DIV (X), DC range, inspect wave profile. (Scheme 179) If wave profile or voltage are out of specification, go to next step.
3. Power Supply Voltage Inspection Disconnect VSS 3-pin harness connector. Turn ignition on. Measure voltage at VSS 3-pin harness connector terminal "B" (Violet/Red wire). VSS voltage reading should be 4.5-5.5 volts. If VSS voltage reading is not as specified, go to next step.
4. Open/Short Circuit Inspection Disconnect PCM 104-pin harness connector and VSS 3-pin harness connector. Using ohmmeter, check following circuits: Power circuit - check for short or open circuit in White/Red wire between VSS 3-pin harness connector terminal "A" and main relay 4-pin harness connector terminal "D". Ground circuit - check for open circuit in Black/Orange wire between VSS 3-pin harness connector terminal "C" and ground. If open/short circuit is present, repair short or open circuit in appropriate wire or replace wire harness as necessary. If open/short circuit is not present, go to next step.
5. Sensor Rotor Inspection Remove VSS. Shift selector lever to "N" position. Inspect sensor rotor surface through hole for VSS while rotating front wheel by hand. Ensure sensor rotor surface does not have metal particles or shavings and is not cracked or damaged. Clean or replace sensor rotor as necessary. If sensor rotor is okay, replace VSS.

Scheme 179

MAIN RELAY

Note. On MAZDA6, when testing ET control relay, use main relay testing procedure.

1. Ensure main relay clicks when ignition is turned on and off. If no sound is heard, locate and remove main relay from main fuse box, in engine compartment. Using ohmmeter, check continuity between main relay terminals "C" and "D". (Scheme 180)and (Scheme 181). Continuity should not be present.
2. Using fused jumper wires, apply battery voltage to main relay terminal "A" and ground terminal "B" (terminal E" on MAZDA6 & MPV). Continuity should be present between main relay terminals "C" and "D". (Scheme 180)and (Scheme 181). If continuity is not as specified, replace main relay.

Scheme 180

Scheme 181

EGR BOOST SENSOR SOLENOID VALVE

Note. EGR boost sensor solenoid valve is not used on Mazda6 2.3L.

Remove EGR boost sensor solenoid valve. See EGR BOOST SOLENOID LOCATIONS table. Apply air pressure to port "B" of solenoid valve. Air should flow from port "C" only. Using fused jumper wires, apply battery voltage to solenoid valve terminals. Apply air pressure to port "A" of solenoid valve. Air should flow from port "B" only. If EGR boost sensor solenoid valve does not operate as specified, replace valve.

EGR BOOST SOLENOID LOCATIONS

PRESSURE REGULATOR CONTROL SOLENOID VALVE

Note. Pressure Regulator Control (PRC) solenoid valve is only used on Protege and Protege5.

Disconnect vacuum hose from PRC solenoid valve. See PRC SOLENOID VALVE LOCATIONS table. Apply air pressure to PRC solenoid valve port "B". (Scheme 182) Air should flow from port "C" only. Using fused jumper wires, apply battery voltage to solenoid terminals. Apply air pressure to PRC solenoid valve port "B". Air should flow through PRC solenoid valve air filter (port "A") only. If PRC solenoid valve operation is not as specified, replace PRC solenoid valve.

PRC SOLENOID VALVE LOCATIONS

Scheme 182

PURGE SOLENOID VALVE

See FUEL EVAPORATIVE SYSTEM (EXCEPT PROTEGE & PROTEGE5) or FUEL EVAPORATIVE SYSTEM (PROTEGE & PROTEGE5) under EMISSION SYSTEMS & SUB-SYSTEMS.

VARIABLE AIR DUCT SHUTTER VALVE - MAZDA6

See VARIABLE AIR DUCT SYSTEM - MAZDA6 under AIR INDUCTION SYSTEMS.

VARIABLE AIR DUCT CONTROL SOLENOID VALVE - MAZDA6

See VARIABLE AIR DUCT SYSTEM - MAZDA6 under AIR INDUCTION SYSTEMS.

VARIABLE INERTIA CHARGE SYSTEM SOLENOID VALVE - PROTEGE & PROTEGE5

See VARIABLE INERTIA CHARGE SYSTEM - PROTEGE & PROTEGE5 under AIR INDUCTION SYSTEMS.

VARIABLE INTAKE-AIR SYSTEM - MAZDA6 (2.3L)

See VARIABLE INTAKE-AIR SYSTEM - MAZDA6 (2.3L) under AIR INDUCTION SYSTEMS.

VARIABLE TUMBLE CONTROL SYSTEM SOLENOID - MAZDA6 (2.3L)

See VARIABLE TUMBLE CONTROL SYSTEM - MAZDA6 (2.3L) under AIR INDUCTION SYSTEMS.

VARIABLE TUMBLE CONTROL SYSTEM SOLENOID - MIATA

See VARIABLE TUMBLE CONTROL SYSTEM - MIATA, PROTEGE & PROTEGE5 under AIR INDUCTION SYSTEMS.

FUEL PRESSURE RELEASE

Remove fuel filler cap. On Miata, disconnect fuel pump relay 6-pin harness connector. On all other models, disconnect fuel pump relay. See FUEL PUMP RELAY LOCATIONS table under RELAYS & SOLENOIDS. Start engine (if possible) and allow to die. Crank engine several times. Turn ignition off. Reconnect fuel pump relay. Reinstall fuel filler cap.

FUEL DELIVERY

Note. For fuel system pressure testing, see BASIC DIAGNOSTIC PROCEDURES article.

Fuel Pump Circuit

1. Fuel pump is located inside fuel tank. Locate DLC-1 on left side of engine compartment. Connect a fused jumper wire between DLC-1 "F/P" terminal and body ground. (Scheme 183) Remove fuel filler cap. Turn ignition on. Listen for fuel pump operation at fuel filler pipe. If fuel pump does not operate, go to next step. If fuel pump operation is heard, reinstall fuel filler cap. Testing is complete.
2. Disconnect fuel pump 4-pin harness connector. Refer to «FUEL PUMP»(ref-151901-S31322102102003010900000) under FUEL SYSTEM in REMOVAL, OVERHAUL & INSTALLATION article. Using DVOM, check for continuity between fuel pump 4-pin connector terminals "B" and "D". (Scheme 184), (Scheme 185) or (Scheme 186). If continuity is not present, replace fuel pump. If continuity is present, check for open or short circuit in wiring harness between fuel pump, fuel pump relay and body ground. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.

Scheme 183

Scheme 184

Scheme 185

Scheme 186

Note. Fuel Pump Maximum Pressure Inspection procedure and specifications for Mazda6 are not available from manufacturer.

Fuel Pressure Regulator

Check fuel pressure. See FUEL SYSTEM in BASIC DIAGNOSTIC PROCEDURES article. If fuel pressure is not as specified, repair fuel system as necessary. See appropriate SYSTEM & COMPONENT TESTING article

FUEL CONTROL

Note. Fuel rail may also be referred to as fuel distributor.

Fuel Injectors

Using stethoscope, listen for normal clicking sound at each injector during idle and acceleration. If clicking sound is not heard, check injector wiring circuit, or main relay and circuit.

Fuel Injector Leakage

1. Using mechanics wire, secure each fuel injector to fuel rail. Disconnect fuel injector connectors. Remove fuel rail assembly from intake manifold. See «REMOVAL, OVERHAUL & INSTALLATION»(ref-151901) article. Reconnect fuel lines to fuel rail. Locate underhood DLC-1 in left side of engine compartment.
2. Connect a fused jumper wire between underhood DLC-1 terminals "F/P" and GND. see scheme 63 Turn ignition on. Tilt injectors about 60 degrees and check fuel injector nozzles for fuel leaks. Fuel leakage should be less than one drop every 2 minutes. If excessive fuel leakage is present, replace faulty fuel injector.

Fuel Injector Resistance - Mazda6 (2.3L)

1. Resistance Inspection Disconnect fuel injector 2-pin harness connector. Using ohmmeter, measure resistance between fuel injector terminals. See «FUEL INJECTOR RESISTANCE SPECIFICATIONS»(ref-151892-S30777013662003010900000) table. If fuel injector resistance reading is as specified, go to next step. If resistance reading is not as specified, replace faulty fuel injector(s) as necessary.
2. Open Circuit Inspection Check for continuity between following terminals: No. 1 cylinder fuel injector harness connector terminal "B" and PCM 30-pin harness connector terminal No. 4Z. No. 2 cylinder fuel injector harness connector terminal "B" and PCM 30-pin harness connector terminal No. 4W. No. 3 cylinder fuel injector harness connector terminal "B" and PCM 30-pin harness connector terminal No. 4AD. No. 4 cylinder fuel injector harness connector terminal "B" and PCM 30-pin harness connector terminal No. 4AA. No. 1 cylinder fuel injector harness connector terminal "A" and main relay 4-pin harness connector terminal "C" through common connector. No. 2 cylinder fuel injector harness connector terminal "A" and main relay 4-pin harness connector terminal "C" through common connector. No. 3 cylinder fuel injector harness connector terminal "A" and main relay 4-pin harness connector terminal "C" through common connector. No. 4 cylinder fuel injector harness connector terminal "A" and main relay 4-pin harness connector terminal "C" through common connector. If continuity is present, go to next step. If continuity is not present, repair open circuit in suspect wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
3. Short Circuit Inspection Check for continuity between following: No. 1 cylinder fuel injector harness connector terminal "B" and ground. No. 2 cylinder fuel injector harness connector terminal "B" and ground. No. 3 cylinder fuel injector harness connector terminal "B" and body GND. No. 4 cylinder fuel injector harness connector terminal "B" and ground. No. 1 cylinder fuel injector harness connector terminal "A" and power supply. No. 2 cylinder fuel injector harness connector terminal "A" and power supply. No. 3 cylinder fuel injector harness connector terminal "A" and power supply. No. 4 cylinder fuel injector harness connector terminal "A" and power supply. If continuity is present, repair short circuit in suspect wire or replace wire harness.

FUEL INJECTOR RESISTANCE SPECIFICATIONS

Fuel Injector Resistance - Mazda6 (3.0L)

1. Resistance Inspection Disconnect fuel injector 2-pin harness connector. Using ohmmeter, measure resistance between injector terminals. See «FUEL INJECTOR RESISTANCE SPECIFICATIONS»(ref-151892-S30777013662003010900000) table. If fuel injector resistance is as specified, check for open or short circuit, go to next step. If fuel injector resistance reading is not as specified, replace faulty injector(s) as necessary.
2. Open Circuit Inspection Disconnect PCM 104-pin harness connector. Check for continuity between following terminals: No. 1 cylinder fuel injector harness connector terminal "A" (Black/White wire) and PCM 104-pin harness connector terminal No. 75 (Yellow/Black wire). No. 2 cylinder fuel injector harness connector terminal "A" (Black/Yellow wire) and PCM 104-pin harness connector terminal No. 101 (Red/Blue wire). No. 3 cylinder fuel injector harness connector terminal "A" (Black/Blue wire) and PCM 104-pin harness connector terminal No. 74 (Yellow/Red wire). No. 4 cylinder fuel injector harness connector terminal "A" (Black/Orange wire) and PCM 104-pin harness connector terminal No. 100 (Yellow/Blue wire). No. 5 cylinder fuel injector harness connector terminal "A" (Black/Green wire) and PCM 104-pin harness connector terminal No. 73 (Black/Red wire). No. 6 cylinder fuel injector harness connector terminal "A" (Black/Red wire) and PCM 104-pin harness connector terminal No. 99 (Blue/White wire). No. 1 cylinder fuel injector harness connector terminal "B" (Green/White wire) and main relay 4-pin harness connector terminal "C" (White/Blue wire) through common connector. No. 2 cylinder fuel injector harness connector terminal "B" (Green/Yellow wire) and main relay 4-pin harness connector terminal "C" (White/Blue wire) through common connector. No. 3 cylinder fuel injector harness connector terminal "B" (Green/Blue wire) and main relay 4-pin harness connector terminal "C" (White/Blue wire) through common connector. No. 4 cylinder fuel injector harness connector terminal "B" (Green/Red wire) and main relay 4-pin harness connector terminal "C" (White/Blue wire) through common connector. No. 5 cylinder fuel injector harness connector terminal "B" (Green/Black wire) and main relay 4-pin harness connector terminal "C" (White/Blue wire) through common connector. No. 6 cylinder fuel injector harness connector terminal "B" (Green/Orange wire) and main relay 4-pin harness connector terminal "C" (White/Blue wire) through common connector. If continuity is present, go to next step. If continuity is not present, repair open circuit in suspect wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
3. Short Circuit Inspection Check for continuity between following: No. 1 cylinder fuel injector harness connector terminal "A" (Black/White wire) and ground. No. 2 cylinder fuel injector harness connector terminal "A" (Black/Yellow wire) and ground. No. 3 cylinder fuel injector harness connector terminal "A" (Black/Blue wire) and ground. No. 4 cylinder fuel injector harness connector terminal "A" (Black/Orange wire) and ground. No. 5 cylinder fuel injector harness connector terminal "A" (Black/Green wire) and ground. No. 6 cylinder fuel injector harness connector terminal "A" (Black/Red wire) and ground. No. 1 cylinder fuel injector harness connector terminal "B" (Green/White wire) and power supply. No. 2 cylinder fuel injector harness connector terminal "B" (Green/Yellow wire) and power supply. No. 3 cylinder fuel injector harness connector terminal "B" (Green/Blue wire) and power supply. No. 4 cylinder fuel injector harness connector terminal "B" (Green/Red wire) and power supply. No. 5 cylinder fuel injector harness connector terminal "B" (White/Blue wire) and power supply. No. 6 cylinder fuel injector harness connector terminal "B" (Green/Orange wire) and power supply. If continuity is present, repair short circuit in suspect wire or replace wire harness.

Fuel Injector Resistance - Miata

1. Resistance Inspection Disconnect fuel injector 2-pin harness connector. Using ohmmeter, measure resistance between fuel injector terminals. See «FUEL INJECTOR RESISTANCE SPECIFICATIONS»(ref-151892-S30777013662003010900000) table. If fuel injector resistance is as specified, check for open or short circuit, go to next step. If fuel injector resistance reading is not as specified, replace faulty fuel injector(s) as necessary.
2. Open Circuit Inspection Check for continuity between following terminals: GND circuit - No. 1 cylinder fuel injector harness connector terminal "B" and PCM 17-pin harness connector terminal No. 2A (Yellow/Black wire). GND circuit - No. 2 cylinder fuel injector harness connector terminal "B" and PCM 17-pin harness connector terminal No. 2D (Violet/Green wire). GND circuit - No. 3 cylinder fuel injector harness connector terminal "B" and PCM 17-pin harness connector terminal No. 2G (Yellow/Red wire). GND circuit - No. 4 cylinder fuel injector harness connector terminal "B" and PCM 17-pin harness connector terminal No. 2J (Yellow/Green wire). Power circuit - No. 1 cylinder fuel injector harness connector terminal "A" (Green/Blue wire) and main relay 4-pin harness connector terminal "D" (White/Blue wire) through common connector. Power circuit - No. 2 cylinder fuel injector harness connector terminal "A" (Green/Blue wire) and main relay 4-pin harness connector terminal "D" (White/Blue wire) through common connector. Power circuit - No. 3 cylinder fuel injector harness connector terminal "A" (Green/Blue wire) and main relay 4-pin harness connector terminal "D" (White/Blue wire) through common connector. Power circuit - No. 4 cylinder fuel injector harness connector terminal "A" (Green/Blue wire) and main relay 4-pin harness connector terminal "D" (White/Blue wire) through common connector. If continuity is present, go to next step. If continuity is not present, repair open circuit in suspect wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
3. Short Circuit Inspection Check for continuity between following: No. 1 cylinder fuel injector harness connector terminal "B" and PCM 17-pin harness connector terminal No. 2A (Yellow/Black wire) to ground. No. 2 cylinder fuel injector harness connector terminal "B" and PCM 17-pin harness connector terminal No. 2D (Violet/Green wire) to ground. No. 3 cylinder fuel injector harness connector terminal "B" and PCM 17-pin harness connector terminal No. 2G (Yellow/Red wire) to ground. No. 4 cylinder fuel injector harness connector terminal "B" and PCM 17-pin harness connector terminal No. 2J (Yellow/Green wire) to ground. If continuity is present, repair short circuit in suspect wire or replace wire harness.

Fuel Injector Resistance - MPV

1. Resistance Inspection Disconnect fuel injector 2-pin harness connector. Using ohmmeter, measure resistance between fuel injector terminals. See «FUEL INJECTOR RESISTANCE SPECIFICATIONS»(ref-151892-S30777013662003010900000) table. If fuel injector resistance is as specified, check for open or short circuit, go to next step. If fuel injector resistance reading is not as specified, replace faulty fuel injector(s) as necessary.
2. Open Circuit Inspection Disconnect PCM 104-pin harness connector. Connect 104-Pin Breakout Box (49-UN01-130) to PCM harness connector only. (Scheme 147) Check for continuity between following terminals: No. 1 cylinder fuel injector harness connector terminal "A" (Tan wire) and breakout box terminal No. 75. No. 2 cylinder fuel injector harness connector terminal "A" (White wire) and breakout box terminal No. 101. No. 3 cylinder fuel injector harness connector terminal "A" (Brown/Yellow wire) and breakout box terminal No. 74. No. 4 cylinder fuel injector harness connector terminal "A" (Brown/Light Blue wire) breakout box terminal No. 100. No. 5 cylinder fuel injector harness connector terminal "A" (Tan/Black wire) and breakout box terminal No. 73. No. 6 cylinder fuel injector harness connector terminal "A" (Light Green/Orange wire) and breakout box terminal No. 99. No. 1 cylinder fuel injector harness connector terminal "B" (Red wire) and main relay 4-pin harness connector terminal "D" (Yellow wire) through common connector. No. 2 cylinder fuel injector harness connector terminal "B" (Red wire) and main relay 4-pin harness connector terminal "D" (Yellow wire) through common connector. No. 3 cylinder fuel injector harness connector terminal "B" (Red wire) and main relay 4-pin harness connector terminal "D" (Yellow wire) through common connector. No. 4 cylinder fuel injector harness connector terminal "B" (Red wire) and main relay 4-pin harness connector terminal "D" (Yellow wire) through common connector. No. 5 cylinder fuel injector harness connector terminal "B" (Red wire) and main relay 4-pin harness connector terminal "D" (Yellow wire) through common connector. No. 6 cylinder fuel injector harness connector terminal "B" (Red wire) and main relay 4-pin harness connector terminal "D" (Yellow wire) through common connector. If continuity is present, go to next step. If continuity is not present, repair open circuit in suspect wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
3. Short Circuit Inspection Check for continuity between following: No. 1 cylinder fuel injector harness connector terminal "B" (Tan wire) and breakout box terminal No. 75 to ground. No. 2 cylinder fuel injector harness connector terminal "B" (White wire) and breakout box terminal No. 101 to ground. No. 3 cylinder fuel injector harness connector terminal "B" (Brown/Yellow wire) and breakout box terminal No. 74 to ground. No. 4 cylinder fuel injector harness connector terminal "B" (Brown/Light Blue wire) and breakout box terminal No. 100 to ground. No. 5 cylinder fuel injector harness connector terminal "B" (Tan/Black wire) and breakout box terminal No. 73. No. 6 cylinder fuel injector harness connector terminal "B" (Light Green/Orange wire) and breakout box terminal No. 99. If continuity is present, repair short circuit in suspect wire or replace wire harness.

Fuel Injector Resistance - Protege & Protege5

1. Resistance Inspection Disconnect fuel injector 2-pin harness connector. Using ohmmeter, measure resistance between fuel injector terminals. See «FUEL INJECTOR RESISTANCE SPECIFICATIONS»(ref-151892-S30777013662003010900000) table. If fuel injector resistance is as specified, check for open or short circuit, go to next step. If fuel injector resistance reading is not as specified, replace faulty fuel injector(s) as necessary.
2. Open Circuit Inspection Disconnect PCM 104-pin harness connector. Connect 104-Pin Breakout Box (49-UN01-130) to PCM harness connector only. (Scheme 147) Check for continuity between following terminals: No. 1 cylinder fuel injector harness connector terminal "B" (Black/Red wire) and breakout box terminal No. 75. No. 2 cylinder fuel injector harness connector terminal "B" (Blue/Orange wire) and breakout box terminal No. 101. No. 3 cylinder fuel injector harness connector terminal "B" (Blue/White wire) and breakout box terminal No. 74. No. 4 cylinder fuel injector harness connector terminal "B" (Green/Black wire) and breakout box terminal No. 100. No. 1 cylinder fuel injector harness connector terminal "A" and main relay 4-pin harness connector terminal "D" (White/Yellow wire) through common connector. No. 2 cylinder fuel injector harness connector terminal "A" and main relay 4-pin harness connector terminal "D" (White/Yellow wire) through common connector. No. 3 cylinder fuel injector harness connector terminal "A" and main relay 4-pin harness connector terminal "D" (White/Yellow wire) through common connector. No. 4 cylinder fuel injector harness connector terminal "A" and main relay 4-pin harness connector terminal "D" (White/Yellow wire) through common connector. If continuity is present, go to next step. If continuity is not present, repair open circuit in suspect wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
3. Short Circuit Inspection Check for continuity between following: No. 1 cylinder fuel injector harness connector terminal "B" (Black/Red wire) and breakout box terminal No. 75 to ground. No. 2 cylinder fuel injector harness connector terminal "B" (Blue/Orange wire) and breakout box terminal No. 101 to ground. No. 3 cylinder fuel injector harness connector terminal "B" (Blue/White wire) and breakout box terminal No. 74 to ground. No. 4 cylinder fuel injector harness connector terminal "B" (Green/Black wire) and breakout box terminal No. 100 to ground. If continuity is present, repair short circuit in suspect wire or replace wire harness.

Fuel Injector Volume

1. Disconnect battery. Remove fuel rail assembly and fuel injectors from intake manifold. See «REMOVAL, OVERHAUL & INSTALLATION»(ref-151901) article.
2. Using a fused jumper wire, connect DLC-1 connector terminals F/P and GND. Connect aftermarket fuel injector tester to fuel injector. Turn ignition on for 15 seconds. Measure each fuel injector output volume. See «FUEL INJECTOR OUTPUT VOLUME SPECIFICATIONS»(ref-151892-S10375236872003010900000) table. If fuel injector output volume is not as specified, replace fuel injector.
3. When all fuel injectors have been checked, remove fuel injector tester and reinstall all components. Check system for leaks.

FUEL INJECTOR OUTPUT VOLUME SPECIFICATIONS

SYSTEM CHECK

1. Ensure engine is at ambient temperature. Connect scan tool to DLC-2. Using PID/DATA MONITOR AND RECORD function, select ECT and RPM PIDs. Start engine.
2. Engine speed should decrease as engine reaches operating temperature. If engine speed does not decrease or decreases slowly, check ECT sensor, IAC valve and related wiring.

IDLE AIR CONTROL VALVE

Note. Idle Air Control (IAC) valve is not used on Mazda6.

1. Resistance Inspection Disconnect IAC valve 2-pin harness connector. See «IAC VALVE LOCATION»(ref-151892-S06395209032003010900000) table. Using an ohmmeter, measure resistance between IAC valve terminals. See «IAC VALVE RESISTANCE SPECIFICATIONS»(ref-151892-S01075374522003010900000) table. If IAC valve is okay, check for open or short circuit. Go to next step. If resistance reading is not within specification, replace IAC valve.
2. Open Circuit Inspection Disconnect PCM 17-pin harness connector. Check for continuity between following terminals: Power circuit - IAC valve harness connector terminal "A" and PCM 17-pin harness connector terminal No. 2P (Orange wire). GND circuit - IAC valve harness connector terminal "B" and PCM 17-pin harness connector terminal No. 2Q (Violet/Red wire). If continuity is present, go to next step. If continuity is not present, repair open circuit in suspect wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
3. Short Circuit Inspection Check for continuity in Orange wire between IAC valve harness connector terminal "A" and PCM 17-pin harness connector terminal No. 2P to ground. If continuity is present, repair short circuit in Orange wire between PCM 17-pin harness connector No. 2P and IAC valve harness connector terminal "A".

IAC VALVE LOCATION

IAC VALVE RESISTANCE SPECIFICATIONS

1. Resistance Inspection Disconnect Idle Air Control (IAC) valve 2-pin harness connector. See «IAC VALVE LOCATION»(ref-151892-S06395209032003010900000) table. Using an ohmmeter, measure resistance between IAC valve terminals. See «IAC VALVE RESISTANCE SPECIFICATIONS»(ref-151892-S01075374522003010900000) table. If IAC valve is okay, check for open or short circuit. Go to next step. If resistance reading is not within specification, replace IAC valve.
2. Open Circuit Inspection Disconnect PCM 104-pin harness connector. Connect 104-Pin Breakout Box (49-UN01-130) to PCM harness connector only. (Scheme 147) Check for continuity between following terminals: IAC valve harness connector terminal "A" (White/Red wire) and breakout box terminal No. 54. IAC valve harness connector terminal "B" (White/Light Blue wire) and breakout box terminal No. 83. If continuity is present, go to next step. If continuity is not present, repair open circuit in suspect wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
3. Short Circuit Inspection Check for continuity between following: IAC valve harness connector terminal "A" (White/Red wire) and power supply. IAC valve harness connector terminal "A" (White/Red wire) and ground IAC valve harness connector terminal "B" (White/Light Blue wire) and power supply. IAC valve harness connector terminal "B" (White/Light Blue wire) and ground. If continuity is present, repair short circuit in suspect wire or replace wire harness.

1. Resistance Inspection Disconnect Idle Air Control (IAC) valve 2-pin harness connector. See «IAC VALVE LOCATION»(ref-151892-S06395209032003010900000) table. Using an ohmmeter, measure resistance between IAC valve terminals. See «IAC VALVE RESISTANCE SPECIFICATIONS»(ref-151892-S01075374522003010900000) table. If IAC valve is okay, check for open or short circuit. Go to next step. If resistance reading is not within specification, replace IAC valve.
2. Open Circuit Inspection Disconnect PCM 104-pin harness connector. Connect 104-Pin Breakout Box (49-UN01-130) to PCM harness connector only. (Scheme 147) Check for continuity between following terminals: Power circuit - IAC valve harness connector terminal "A" (Brown wire) and breakout box terminal No. 54. GND circuit - IAC valve harness connector terminal "B" (Gray wire) and breakout box terminal No. 83. If continuity is present, go to next step. If continuity is not present, repair open circuit in suspect wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
3. Short Circuit Inspection Power circuit - IAC valve harness connector terminal "A" and breakout box terminal No. 54 (Brown wire) to ground. GND circuit - IAC valve harness connector terminal "B" and breakout box terminal No. 83 (Gray wire) to ground. If continuity is present, repair short circuit in suspect wire or replace wire harness.

THROTTLE ACTUATOR

Note. Throttle actuator and throttle position sensor are integral parts of the throttle body and are not serviced separately.

Scheme 187

1. Resistance Inspection Disconnect negative battery cable. Disconnect throttle body 6-pin harness connector. Using DVOM, measure resistance between throttle actuator terminals "E" and "F". (Scheme 187) If resistance reading is.3-100 ohms, check for open or short circuit. Go to next step. If resistance reading is not as specified, replace throttle body.
2. Open Circuit Inspection Disconnect PCM 30-pin harness connector. Check for continuity between following terminals: Throttle actuator 6-pin harness connector terminal "E" (Black wire) and PCM 30-pin harness connector terminal No. 4AB (Blue/White wire) through common connector. Throttle actuator 6-pin harness connector terminal "F" (White/Green wire) and PCM 30-pin harness connector terminal No. 4Y (Blue/Black wire) through common connector. If continuity is present, go to next step. If continuity is not present, repair open circuit in suspect wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
3. Short Circuit Inspection Check for continuity between following: Throttle actuator 6-pin harness connector terminal "E" (Blue/White wire) and power supply. Throttle actuator 6-pin harness connector terminal "E" (Blue/White wire) and ground. Throttle actuator 6-pin harness connector terminal "F" (White/Green wire) and power supply. Throttle actuator 6-pin harness connector terminal "F" (White/Green wire) and ground. If continuity is present, repair short circuit in suspect wire or replace wire harness.

Scheme 188

1. Resistance Inspection Disconnect negative battery cable. Disconnect throttle body 6-pin harness connector. Using DVOM, measure resistance between throttle actuator terminals "A" and "B". (Scheme 188) If resistance reading is about 80 ohms, check for open or short circuit. Go to next step. If resistance reading is not as specified, replace throttle body.
2. Open Circuit Inspection Disconnect PCM 104-pin harness connector. Check for continuity between following terminals: Throttle actuator 6-pin harness connector terminal "A" (Black/Orange wire) and PCM 104-pin harness connector terminal No. 80 (Blue/White wire) through common connector. Throttle actuator 6-pin harness connector terminal "B" (Green/Red wire) and PCM 104-pin harness connector terminal No. 54 (Blue/Black wire) through common connector. If continuity is present, go to next step. If continuity is not present, repair open circuit in suspect wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
3. Short Circuit Inspection Check for continuity between following: Throttle actuator 6-pin harness connector terminal "A" (Black/Orange wire) and power supply. Throttle actuator 6-pin harness connector terminal "A" (Black/Orange wire) and ground. Throttle actuator 6-pin harness connector terminal "B" (Green/Red wire) and power supply. Throttle actuator 6-pin harness connector terminal "B" (Green/Red wire) and ground. If continuity is present, repair short circuit in suspect wire or replace wire harness.

Ignition Coil Resistance - Mazda6 (2.3L)

Primary Coil Resistance - Disconnect ignition coil 3-pin harness connector. Measure resistance between terminals "A" and "B" and terminals "B" and "C" using a DVOM. Resistance reading should be as specified in table. See IGNITION COIL RESISTANCE SPECIFICATIONS table. If resistance reading is not as specified, replace ignition coil.

Scheme 189

Secondary Coil Resistance - Disconnect ignition coil 3-pin harness connector. Remove ignition coil. Measure resistance between coil towers No. 1 and 4 and between coil towers No. 2 and 3. Resistance should be as specified in table. See IGNITION COIL RESISTANCE SPECIFICATIONS table. If resistance is not as specified, replace ignition coil.

Ignition Coil Case Insulation Resistance - Mazda6, Miata, Protege & Protege5

Disconnect high-tension lead. Disconnect ignition coil harness connector. On Mazda6 2.3L, measure insulation resistance from 3-pin connector terminal "B" to ignition coil case. (Scheme 190) On Mazda6 3.0L, measure insulation resistance from 2-pin connector terminal "A" to ignition coil case. (Scheme 191) On Miata, Protege and Protege5, measure insulation resistance from 3-pin connector terminal No. 1A to ignition coil case, and terminal No. 2A to ignition coil case. (Scheme 192) If resistance reading is not more than 10 megohms, replace ignition coil.

Scheme 190

Scheme 191

Scheme 192

Ignition Coil Resistance - Miata, Protege & Protege5

Using an ohmmeter, measure secondary resistance between coil towers No. 1 and 4 and between coil towers No. 2 and 3. (Scheme 193) Resistance should be as specified in table. See IGNITION COIL RESISTANCE SPECIFICATIONS table. If resistance is not as specified, replace appropriate ignition coil.

IGNITION COIL RESISTANCE SPECIFICATIONS

Scheme 193

Ignition Coil Resistance - Mazda6 (3.0L) & MPV

1. Disconnect ignition coil 2-pin harness connector. Using DVOM, measure primary resistance between ignition coil terminals "A" and "B". (Scheme 194) Resistance reading should be as specified in table. See «IGNITION COIL RESISTANCE SPECIFICATIONS»(ref-151892-S40315469622003010800000) table. If resistance reading is as specified, go to next step. If resistance reading is not as specified, replace ignition coil.
2. Using a DVOM, measure secondary resistance between ignition coil terminal "A" and coil tower boot socket. See «IGNITION COIL RESISTANCE SPECIFICATIONS»(ref-151892-S40315469622003010800000) table. If resistance reading is not as specified, replace ignition coil.

Scheme 194

EGR Valve - Mazda6 (2.3L)

1. Resistance Inspection Disconnect EGR valve 6-pin harness connector. (Scheme 195) Using an ohmmeter, measure resistance between EGR valve terminals "C" and "E", "C" and "A", "D" and "B" and between "D" and "F". See «EGR VALVE RESISTANCE SPECIFICATIONS»(ref-151892-S11181602832003050100000) table. If resistance is as specified, check for open or short circuit. Go to next step. If resistance is not as specified, replace EGR valve.
2. Open Circuit Inspection Disconnect PCM 30-pin harness connector. Check for continuity between following terminals: EGR valve 6-pin harness connector terminal "E" and PCM 30-pin harness connector terminal No. 4E (Red/Green wire). EGR valve 6-pin harness connector terminal "A" and PCM 30-pin harness connector terminal No. 4H (Pink wire). EGR valve 6-pin harness connector terminal "B" and PCM 30-pin harness connector terminal No. 4K (Gray wire). EGR valve 6-pin harness connector terminal "F" and PCM 30-pin harness connector terminal No. 4N (Yellow wire). EGR valve 6-pin harness connector terminal "C" or "D" and main relay 4-pin harness connector terminal "C" (White wire). If continuity is present, go to next step. If continuity is not present, repair open circuit in suspect wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
3. Short Circuit Inspection Check for continuity between following: EGR valve 6-pin harness connector terminal "E" (Red/Green wire) and ground. EGR valve 6-pin harness connector terminal "A" (Pink wire) and ground. EGR valve 6-pin harness connector terminal "B" (Gray wire) and ground. EGR valve 6-pin harness connector terminal "F" (Yellow wire) and ground. EGR valve 6-pin harness connector terminal "C" or "D" (White wire) and power supply. If continuity is present, repair short circuit in suspect wire or replace wire harness. If no open or short circuit is present, remove EGR valve and inspect for any damage or clogging. If there is no damage or clogging, replace EGR valve.

EGR VALVE RESISTANCE SPECIFICATIONS

Scheme 195

EGR Valve - Mazda6 (3.0L)

1. Resistance Inspection Disconnect EGR valve 6-pin harness connector. (Scheme 195) Using an ohmmeter, measure resistance between EGR valve terminals "C" and "E", "C" and "A", "D" and "B" and between "D" and "F". See «EGR VALVE RESISTANCE SPECIFICATIONS»(ref-151892-S11181602832003050100000) table. If resistance is as specified, check for open or short circuit. Go to next step. If resistance is not as specified, replace EGR valve.
2. Open Circuit Inspection Disconnect PCM 104-pin harness connector. Check for continuity between following terminals: EGR valve 6-pin harness connector terminal "E" and PCM 104-pin harness connector terminal No. 12 (Red/Green wire). EGR valve 6-pin harness connector terminal "A" and PCM 104-pin harness connector terminal No. 72 (Pink wire). EGR valve 6-pin harness connector terminal "B" and PCM 104-pin harness connector terminal No. 46 (Gray wire). EGR valve 6-pin harness connector terminal "F" and PCM 104-pin harness connector terminal No. 56 (Yellow wire). EGR valve 6-pin harness connector terminal "C" or "D" and main relay 4-pin harness connector terminal "C" (White wire). If continuity is present, go to next step. If continuity is not present, repair open circuit in suspect wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
3. Short Circuit Inspection Check for continuity between following: EGR valve 6-pin harness connector terminal "E" (Red/Green wire) and ground. EGR valve 6-pin harness connector terminal "A" (Pink wire) and ground. EGR valve 6-pin harness connector terminal "B" (Gray wire) and ground. EGR valve 6-pin harness connector terminal "F" (Yellow wire) and ground. EGR valve 6-pin harness connector terminal "C" or "D" (White wire) and power supply. If continuity is present, repair short circuit in suspect wire or replace wire harness. If no open or short circuit is present, remove EGR valve and inspect for any damage or clogging. If there is no damage or clogging, replace EGR valve.

EGR Valve - Miata

1. Resistance Inspection Disconnect EGR valve 6-pin harness connector. (Scheme 195) Using an ohmmeter, measure resistance between EGR valve terminals "C" and "E", "C" and "A", "D" and "B" and between "D" and "F". See «EGR VALVE RESISTANCE SPECIFICATIONS»(ref-151892-S11181602832003050100000) table. If resistance is as specified, check for open or short circuit. Go to next step. If resistance is not as specified, replace EGR valve.
2. Open Circuit Inspection Disconnect PCM 17-pin harness connector. Check for continuity between following terminals: EGR valve 6-pin harness connector terminal "E" and PCM 17-pin harness connector terminal No. 2E (Light Green wire). EGR valve 6-pin harness connector terminal "A" and PCM 17-pin harness connector terminal No. 2F (White/Green wire). EGR valve 6-pin harness connector terminal "B" and PCM 17-pin harness connector terminal No. 2H (Pink/Black wire). EGR valve 6-pin harness connector terminal "F" and PCM 17-pin harness connector terminal No. 2I (Pink wire). EGR valve 6-pin harness connector terminal "C" or "D" and main relay 4-pin harness connector terminal "C" (White/Red wire). If continuity is present, go to next step. If continuity is not present, repair open circuit in suspect wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
3. Short Circuit Inspection Check for continuity between following: EGR valve 6-pin harness connector terminal "E" (Light Green wire) and ground. EGR valve 6-pin harness connector terminal "A" (White/Green wire) and ground. EGR valve 6-pin harness connector terminal "B" (Pink/Black wire) and ground. EGR valve 6-pin harness connector terminal "F" (Pink wire) and ground. EGR valve 6-pin harness connector terminal "C" or "D" (White/Red wire) and power supply. If continuity is present, repair short circuit in suspect wire or replace wire harness. If no open or short circuit is present, remove EGR valve and inspect for any damage or clogging. If there is no damage or clogging, replace EGR valve.

EGR Valve - MPV

1. Disconnect EGR valve 6-pin harness connector. (Scheme 195) Using an ohmmeter, measure resistance between EGR valve terminals "C" and "E", "C" and "A", "D" and "B" and between "D" and "F". See «EGR VALVE RESISTANCE SPECIFICATIONS»(ref-151892-S11181602832003050100000) table. If resistance is as specified, check for open or short circuit. Go to next step. If resistance is not as specified, replace EGR valve.
2. Open Circuit Inspection Disconnect PCM 104-pin harness connector. Connect 104-Pin Breakout Box (49-UN01-130) to PCM harness connector only. (Scheme 147) Check for continuity between following terminals: EGR valve 6-pin harness connector terminal "E" and PCM 104-pin harness connector terminal No. 12 (Red/Green wire). EGR valve 6-pin harness connector terminal "A" and PCM 104-pin harness connector terminal No. 72 (Pink/Black wire). EGR valve 6-pin harness connector terminal "B" and PCM 104-pin harness connector terminal No. 46 (Black/Orange wire). EGR valve 6-pin harness connector terminal "F" and PCM 104-pin harness connector terminal No. 56 (Pink wire). EGR valve 6-pin harness connector terminal "C" or "D" and main relay 4-pin harness connector terminal "C" (White/Red wire).
3. Short Circuit Inspection Check for continuity between following: EGR valve 6-pin harness connector terminal "E" (Red/Green wire) and ground. EGR valve 6-pin harness connector terminal "A" (Pink/Black wire) and ground. EGR valve 6-pin harness connector terminal "B" (Black/Orange wire) and ground. EGR valve 6-pin harness connector terminal "F" (Pink wire) and ground. EGR valve 6-pin harness connector terminal "C" or "D" (White/Red wire) and power supply. If continuity is present, repair short circuit in suspect wire or replace wire harness. If no open or short circuit is present, remove EGR valve and inspect for any damage or clogging. If there is no damage or clogging, replace EGR valve.

EGR Valve - Protege & Protege5

1. Turn ignition off. Disconnect EGR valve 6-pin harness connector. (Scheme 195) Using an ohmmeter, measure resistance between EGR valve terminals "C" and "E", "C" and "A", "D" and "B" and between "D" and "F". See «EGR VALVE RESISTANCE SPECIFICATIONS»(ref-151892-S11181602832003050100000) table. If resistance is as specified, check for open or short circuit. Go to next step. If resistance is not as specified, replace EGR valve.
2. Open Circuit Inspection Disconnect PCM 104-pin harness connector. Connect 104-Pin Breakout Box (49-UN01-130) to PCM harness connector only. (Scheme 147) Check for continuity between following terminals: EGR valve 6-pin harness connector terminal "E" and breakout box terminal No. 68 (Brown/White wire). EGR valve 6-pin harness connector terminal "A" and breakout box terminal No. 72 (Violet/Green wire). EGR valve 6-pin harness connector terminal "B" and breakout box terminal No. 46 (Light Green wire). EGR valve 6-pin harness connector terminal "F" and breakout box terminal No. 56 (Pink wire). EGR valve 6-pin harness connector terminal "C" or "D" and main relay 4-pin harness connector terminal "C" (White/Red wire).
3. Short Circuit Inspection Check for continuity between following: EGR valve 6-pin harness connector terminal "E" (Brown/White wire) and ground. EGR valve 6-pin harness connector terminal "A" (Violet/Green wire) and ground. EGR valve 6-pin harness connector terminal "B" (Light Green wire) and ground. EGR valve 6-pin harness connector terminal "F" (Pink wire) and ground. EGR valve 6-pin harness connector terminal "C" or "D" (White/Red wire) and power supply. If continuity is present, repair short circuit in suspect wire or replace wire harness. If no open or short circuit is present, remove EGR valve and inspect for any damage or clogging. If there is no damage or clogging, replace EGR valve.

See EGR BOOST SENSOR under ENGINE SENSORS & SWITCHES.

See EGR BOOST SENSOR SOLENOID VALVE under RELAYS & SOLENOIDS.

FUEL EVAPORATIVE SYSTEM - EXCEPT PROTEGE & PROTEGE5

Note. For DTC related procedures, see appropriate SELF-DIAGNOSTICS article.

Air Filter

Remove air filter. see scheme 77and see scheme 85. Blow through filter in both directions. If air flows in both directions, filter is okay. If air does not flow in both directions, replace air filter.

Catch Tank

Remove catch tank. see scheme 77and see scheme 85. Plug one port and apply small amount of air pressure into other port on catch tank. Check for leaks. Replace catch tank if any leaks are present.

Charcoal Canister

Remove charcoal canister and disconnect hoses. See CHARCOAL CANISTER LOCATIONS table. Plug or apply small amount of air pressure to canister ports. See CHARCOAL CANISTER TEST PORT IDENTIFICATION table. (Scheme 196)or (Scheme 197). If any air leaks are present, replace charcoal canister.

CHARCOAL CANISTER TEST PORT IDENTIFICATION

CHARCOAL CANISTER LOCATIONS

Scheme 196

Scheme 197

Evaporative Chamber - Miata Only

Remove evaporative chamber. For location see scheme 83 Blow air into port "A" and verify there is airflow from port "B". (Scheme 198) If airflow is not present at port "B", replace evaporative chamber.

Scheme 198

Fuel Shut-off/Rollover Valves - Mazda6 & MPV

Fuel shut-off/rollover valves are an integral part of fuel tank. If valve(s) are faulty, replace fuel tank.

1. Clean area around fuel line connectors. Disconnect fuel lines and wiring from fuel tank. Remove fuel tank with pump. Plug main pipe at fuel pump unit. Plug port "C". (Scheme 199)or (Scheme 200).
2. Level fuel tank. Blow through port "B". If air flows out of port "A", go to next step. If air does not flow out of port "A", replace tank.
3. Turn tank upside down. Blow through port "B". If air flows out of port "A", replace tank. If air does not flow out of port "A", test is complete.

Scheme 199

Scheme 200

Fuel Shut-Off/Rollover Valves - Miata

Vehicle is equipped with 2 fuel shut-off/rollover valves located in top of fuel tank. Fuel shut-off/rollover valves are part of fuel tank. For location see scheme 83

1. Remove fuel tank. Plug main fuel pipe, return pipe of fuel pump unit and port "A" of fuel tank. (Scheme 201) Level fuel tank. Blow air through port "B" and ensure air flows from port "C". If air flow is not present from port "C", replace fuel tank. If air flow is present, go to next step.
2. Plug port "C". Blow air through port "B" and ensure air flows from port "A". If air flow is not present from port "A", replace fuel tank. If air flow is present, go to next step.
3. Turn fuel tank upside down. With fuel tank turned upside down, blow air through port "B". Ensure air does not flow from port "A". If air flow is present, replace fuel tank.

Scheme 201

Scheme 202

Scheme 203

Scheme 204

1. Air Flow Inspection Locate leak detection pump. see scheme 79 Disconnect hoses from leak detection pump. Blow air into port "A" (charcoal canister side). Air should flow from port "B". (Scheme 202) If air does not flow from port "B" (air filter side), replace EVAP system leak detection pump. Blow air into port "B". Air should flow from port "A". If air does not flow from port "A", replace EVAP system leak detection pump. If EVAP system leak detection pump is as specified, go to next step.
2. Resistance Inspection Disconnect negative battery cable. Disconnect EVAP system leak detection pump 4-pin harness connector. (Scheme 203) Using DVOM, check resistance between appropriate terminals on EVAP system leak detection pump. See «EVAP SYSTEM LEAK DETECTION PUMP RESISTANCE SPECIFICATIONS (Mazda6)»(ref-151892-S22522909262003052100000) table. If resistance readings are within specification, check for open or short circuit. Go to next step. If resistance readings are not as specified, replace EVAP system leak detection pump.
3. Open Circuit Inspection Disconnect PCM harness connectors. Check continuity between following: EVAP system leak detection pump 4-pin harness connector terminal "A" and main relay 4-pin harness connector terminal "D" (White wire). (Scheme 204) EVAP system leak detection pump 4-pin harness connector terminal "B" (Black wire) and ground. EVAP system leak detection pump 4-pin harness connector terminal "C" and PCM 30-pin harness connector terminal No. 3V (Orange wire). EVAP system leak detection pump 4-pin harness connector terminal "D" and PCM 30-pin harness connector terminal No. 3Y (Pink wire). If continuity is present, go to next step. If continuity is not present, repair open circuit in suspect wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
4. Short Circuit Inspection Check for continuity between following: EVAP system leak detection pump 4-pin harness connector terminal "A" (White wire) and ground. EVAP system leak detection pump 4-pin harness connector terminal "B" (Black wire) and power. EVAP system leak detection pump 4-pin harness connector terminal "C" (Orange wire) and power. EVAP system leak detection pump 4-pin harness connector terminal "D" (Pink wire) and power. If continuity is present, repair short circuit in suspect wire or replace wire harness.

EVAP SYSTEM LEAK DETECTION PUMP RESISTANCE SPECIFICATIONS (MAZDA6)

Leak Detection Pump - Mazda6 (3.0L)

1. Air Flow Inspection Locate leak detection pump. see scheme 79 Blow air into port "A" (charcoal canister side). Air should flow from port "B". (Scheme 202) If air does not flow from port "B" (air filter side), replace EVAP system leak detection pump. Blow air into port "B". Air should flow from port "A". If air does not flow from port "A", replace EVAP system leak detection pump. If EVAP system leak detection pump is as specified, go to next step.
2. Resistance Inspection Disconnect negative battery cable. Disconnect EVAP system leak detection pump 4-pin harness connector. Using DVOM, check resistance between appropriate terminals on EVAP system leak detection pump. (Scheme 203) See «EVAP SYSTEM LEAK DETECTION PUMP RESISTANCE SPECIFICATIONS (MAZDA6)»(ref-151892-S22522909262003052100000) table. If resistance readings are within specification, check for open or short circuit. Go to next step. If resistance readings are not as specified, replace EVAP system leak detection pump.
3. Open Circuit Inspection Disconnect PCM 104-pin harness connector. Check continuity between following: EVAP system leak detection pump 4-pin harness connector terminal "A" and main relay terminal "D" (White wire). (Scheme 204) EVAP system leak detection pump 4-pin harness connector terminal "B" (Black wire) and ground. EVAP system leak detection pump 4-pin harness connector terminal "C" and PCM 104-pin harness connector terminal No. 6 (Orange wire). EVAP system leak detection pump 4-pin harness connector terminal "D" and PCM 104-pin harness connector terminal No. 67 (Pink wire). If continuity is present, go to next step. If continuity is not present, repair open circuit in suspect wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
4. Short Circuit Inspection Check for continuity between following: EVAP system leak detection pump 4-pin harness connector terminal "A" (White wire) and ground. EVAP system leak detection pump 4-pin harness connector terminals "B" (Black wire) and power. EVAP system leak detection pump 4-pin harness connector terminals "C" (Orange wire) and power. EVAP system leak detection pump 4-pin harness connector terminals "D" (Pink wire) and power. If continuity is present, repair short circuit in suspect wire or replace wire harness.

Leak Detection Pump - Miata

1. Air Flow Inspection Locate leak detection pump. see scheme 83 Blow air into port "A" (charcoal canister side). Air should flow from port "B". (Scheme 202) If air does not flow from port "B" (air filter side), replace EVAP system leak detection pump. Blow air into port "B". Air should flow from port "A". If air does not flow from port "A", replace EVAP system leak detection pump. If EVAP system leak detection pump is as specified, go to next step.
2. Resistance Inspection Disconnect negative battery cable. Disconnect EVAP system leak detection pump 4-pin harness connector. Using DVOM, check resistance between appropriate terminals on EVAP system leak detection pump. (Scheme 203) See «EVAP SYSTEM LEAK DETECTION PUMP RESISTANCE SPECIFICATIONS (MIATA & MPV)»(ref-151892-S09789680062003010900000) table. If resistance readings are within specification, check for open or short circuit in wiring harness. Go to next step. If resistance readings are not as specified, replace EVAP system leak detection pump. EVAP SYSTEM LEAK DETECTION PUMP RESISTANCE SPECIFICATIONS (MIATA & MPV) Terminals Resistance (ohms) A-B 20-25 A-C 26.6-32.4 A-D About 118
3. Open Circuit Inspection Disconnect PCM 17-pin harness connector. Check for continuity between following terminals: EVAP system leak detection pump 4-pin harness connector terminal "A" and main relay terminal "D" (White/Red wire). (Scheme 204) EVAP system leak detection pump 4-pin harness connector terminal "B" (Black wire) and ground. EVAP system leak detection pump 4-pin harness connector terminal "C" and PCM 17-pin harness connector terminal No. 4AH (Red/Green wire). EVAP system leak detection pump 4-pin harness connector terminal "D" (Yellow/Black wire) and PCM 17-pin harness connector terminal No. 3K. If continuity is present, go to next step. If continuity is not present, repair open circuit in suspect wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
4. Short Circuit Inspection Check for continuity between following: EVAP system leak detection pump 4-pin harness connector terminal "A" (White/Red wire) and ground. EVAP system leak detection pump 4-pin harness connector terminal "B" (Black wire) and power supply. EVAP system leak detection pump 4-pin harness connector terminal "C" (Red/Green wire) and power supply. EVAP system leak detection pump 4-pin harness connector terminal "D" (Yellow/Black wire) and power supply. If continuity is present, repair short circuit in suspect wire or replace wire harness.

Leak Detection Pump - MPV

Disconnect negative battery cable. Remove EVAP system leak detection pump. For location see scheme 85

1. Air Flow Inspection Blow air into port "A" (charcoal canister side). Air should flow from port "B". (Scheme 202) If air does not flow from port "B" (air filter side), replace EVAP system leak detection pump. Blow air into port "B". Air should flow from port "A". If air does not flow from port "A", replace EVAP system leak detection pump. If EVAP system leak detection pump is as specified, go to next step.
2. Resistance Inspection Disconnect negative battery cable. Disconnect EVAP system leak detection pump 4-pin harness connector. Using DVOM, check resistance between appropriate terminals on EVAP system leak detection pump. (Scheme 203) See «EVAP SYSTEM LEAK DETECTION PUMP RESISTANCE SPECIFICATIONS (MIATA & MPV)»(ref-151892-S09789680062003010900000) table. If resistance readings are within specification, check for open or short circuit. Go to next step. If resistance readings are not as specified, replace EVAP system leak detection pump.
3. Open Circuit Inspection Disconnect PCM 104-pin harness connector and install 104-Pin Breakout Box (49-UN01-130) to PCM harness connector only. (Scheme 147) Check for continuity between following terminals: EVAP system leak detection pump 4-pin harness connector terminal "A" (White/Red wire) and main relay terminal "D" (Yellow wire) through common connector. (Scheme 204) EVAP system leak detection pump 4-pin harness connector terminal "B" (Black wire) and ground. EVAP system leak detection pump 4-pin harness connector terminal "C" (Red/Blue wire) and breakout box terminal No. 67. EVAP system leak detection pump 4-pin harness connector terminal "D" (Pink/Blue wire) and breakout box terminal No. 43. If continuity is present, go to next step. If continuity is not present, repair open circuit in suspect wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
4. Short Circuit Inspection Check for continuity between following: EVAP system leak detection pump 4-pin harness connector terminal "A" (White/Red wire) and ground. EVAP system leak detection pump 4-pin harness connector terminals "B" (Black wire) and power. EVAP system leak detection pump 4-pin harness connector terminals "C" (Red/Blue wire) and power. EVAP system leak detection pump 4-pin harness connector terminals "D" (Pink/Blue wire) and power. If continuity is present, repair short circuit in suspect wire or replace wire harness.

Purge Solenoid Valve - Mazda6 2.3L

1. Disconnect purge solenoid valve 2-pin harness connector and vacuum hoses. Purge solenoid valve is located by throttle body. see scheme 77 Ensure air does not flow through purge solenoid valve vacuum ports. Using fused jumper wires. Connect battery voltage to purge solenoid valve terminals. Air should pass through vacuum ports. If purge solenoid valve operates as specified, check for open or short circuit. Go to next step. If purge solenoid valve does not operate as specified, replace purge solenoid valve. Perform the following test only when directed. Disconnect negative battery cable.
2. Open Circuit Disconnect PCM harness connectors. Check continuity between following terminals. Purge solenoid valve 2-pin harness connector terminal "A" and PCM 30-pin harness connector terminal "4U" (Blue/Yellow wire). Purge solenoid valve 2-pin harness connector terminal "B" and main relay terminal "C" (White wire).. If continuity is present, go to next step. If continuity is not present, repair open circuit in suspect wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
3. Short Circuit Check for continuity between following: Purge solenoid valve 2-pin harness connector terminal "A" (Blue/Yellow wire) and body GND Purge solenoid valve 2-pin harness connector terminal "B" (White wire) and power supply If continuity is present, repair short circuit in suspect wire or replace wire harness.

Purge Solenoid Valve - Mazda6 3.0L

1. Disconnect purge solenoid valve 2-pin harness connector and vacuum hoses. Purge solenoid valve is located by throttle body. see scheme 78 Ensure air does not flow through purge solenoid valve vacuum ports. Using fused jumper wires. Connect battery voltage to purge solenoid valve terminals. Air should pass through vacuum ports. If purge solenoid valve operates as specified, check for open or short circuit. Go to next step. If purge solenoid valve does not operate as specified, replace purge solenoid valve. Perform the following test only when directed. Disconnect negative battery cable.
2. Open Circuit Disconnect PCM 104-pin harness connector. Check continuity between following terminals. Purge solenoid valve 2-pin harness connector terminal "B" and PCM 104-pin harness connector terminal No. 18 (Blue/Yellow wire). Purge solenoid valve 2-pin harness connector terminal "A" and main relay terminal "C" (White wire).. If continuity is present, go to next step. If continuity is not present, repair open circuit in suspect wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
3. Short Circuit Check for continuity between following: Purge solenoid valve 2-pin harness connector terminal "B" (Blue/Yellow wire) and body GND Purge solenoid valve 2-pin harness connector terminal "A" (White wire) and power supply If continuity is present, repair short circuit in supect wire or replace wire harness.

Purge Solenoid Valve - Miata

1. Airflow Inspection Disconnect purge solenoid valve 2-pin harness connector and vacuum hoses. Purge solenoid valve is located by throttle body. see scheme 82 Ensure air does not flow through purge solenoid valve vacuum ports. Using fused jumper wires. Connect battery voltage to purge solenoid valve terminals. Air should pass through vacuum ports. If purge solenoid valve operates as specified, check for open or short circuit. Go to next step. If purge solenoid valve does not operate as specified, replace purge solenoid valve.
2. Open Circuit Inspection Disconnect PCM 24-pin harness connector. Check for continuity between following terminals: Purge solenoid valve harness connector terminal "A" and main relay 4-pin harness connector terminal "D" (White/Red wire) through common connector. Purge solenoid valve harness connector terminal "B" and PCM 24-pin harness connector terminal No. 3C (Green/Yellow wire). If continuity is present, go to next step. If continuity is not present, repair open circuit in suspect wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
3. Short Circuit Inspection Check for continuity in Green/Yellow wire between purge solenoid valve harness connector terminal "B" and PCM 24-pin harness connector terminal No. 3C to ground. If continuity is present, repair short circuit in Green/Yellow wire between purge solenoid valve harness connector terminal "B" and PCM 24-pin harness connector terminal No. 3C or replace wire harness.

Purge Solenoid Valve - MPV

1. Airflow Inspection Disconnect purge solenoid valve 2-pin harness connector and vacuum hoses. Purge solenoid valve is located by throttle body. see scheme 84 Ensure air does not flow through purge solenoid valve vacuum ports. Using fused jumper wires. Connect battery voltage to purge solenoid valve terminals. Air should pass through vacuum ports. If purge solenoid valve operates as specified, check for open or short circuit. Go to next step. If purge solenoid valve does not operate as specified, replace purge solenoid valve.
2. Open Circuit Inspection Disconnect PCM 104-pin harness connector. Connect 104-Pin Breakout Box (49-UN01-130) to PCM harness connector only. (Scheme 147) Check for continuity between following: Purge solenoid valve harness connector terminal "B" and breakout box terminal No. 18 (Green/Black wire). Purge solenoid valve harness connector terminal "A" (White/Red wire) and main relay 4-pin harness connector terminal "D" (Yellow wire) through common connector. If continuity is present, go to next step. If continuity is not present, repair open circuit in suspect wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
3. Short Circuit Inspection Check for continuity between following: Purge solenoid valve harness connector terminal "A" (White/Red wire) and power supply. Purge solenoid valve harness connector terminal "B" (Green/Black wire) and ground. If continuity is present, repair short circuit in suspect wire or replace wire harness.

FUEL EVAPORATIVE SYSTEM (PROTEGE & PROTEGE5)

Note. For DTC related procedures, see appropriate SELF-DIAGNOSTICS article.

Remove charcoal canister, located under vehicle at spare tire well and disconnect hoses. see scheme 98 Plug charcoal canister ports "A" and "C" and apply small amount of air pressure to canister port "B". (Scheme 205) If any air leaks are present, replace charcoal canister.

Scheme 205

Remove catch tank. Located at right rear of engine compartment. see scheme 99 Plug purge solenoid valve port on catch tank and apply small amount of air pressure into charcoal canister port. (Scheme 206) Check for leaks. If any leaks are present, replace catch tank.

Scheme 206

Evaporative Gas (Two-Way) Check Valve - Protege & Protege5

Remove check valve, located next to charcoal canister under vehicle at spare tire well. see scheme 98 Connect Air Pressure Tester (49-U014-001) to port "A" of evaporative gas (two-way) check valve. Apply 0.99 kPa of air pressure to port "A". (Scheme 207) Air should flow from port "B". Apply air pressure to port "C". Air should flow from port "A". If airflow is not as specified, replace evaporative gas (two-way) check valve.

Scheme 207

Fuel Shut-Off/Rollover Valves (Protege & Protege5)

Vehicle is equipped with 2 fuel shut-off/rollover valves located in top of fuel tank. see scheme 98 Fuel shut-off/rollover valves are an integral part of fuel tank. Evaporative gas check valve (two-way) is integrated with each rollover valve.

1. Remove fuel tank. Connect Air Pressure Tester (49-U014-001) to an air compressor. Plug main fuel pipe, return pipe of fuel pump unit and port "A" of fuel tank. (Scheme 208) Level fuel tank. Using air pressure tester 49-U014-001, apply 5.9 kPa pressure to port "B" and ensure air flows from port "C". If no airflow is present, replace fuel tank. If airflow is present, go to next step.
2. Connect air pressure tester to port "C" and with port "A" plugged. Apply 2.0 kPa pressure to port "C". Air should flow from port "B". If airflow is not present, replace fuel tank. If airflow is present, go to next step.
3. Connect air pressure tester to port "B" and turn fuel tank upside-down. Apply 0.99 kPa pressure to port "B". Ensure air does not flow from port "C". If airflow is present, replace fuel tank.

Scheme 208

1. Airflow Inspection Remove purge solenoid valve, located on firewall by throttle body. see scheme 99 Apply air pressure to purge solenoid valve port. Ensure air does not flow through purge solenoid valve vacuum ports. Using fused jumper wires, apply battery voltage to purge solenoid valve terminals. Apply air pressure to a solenoid valve port again. Air should flow through purge solenoid valve vacuum ports. If purge solenoid valve operates as specified, check for open or short circuit. Go to next step. If purge solenoid valve does not operate as specified, replace purge solenoid valve.
2. Open Circuit Inspection Remove PCM. See «COMPUTERIZED ENGINE CONTROLS»(ref-151901-S00355033702003010900000) in REMOVAL, OVERHAUL & INSTALLATION article. Connect 104-pin Breakout Box (49-UN01-130) to PCM harness connector only. Disconnect purge solenoid valve 2-pin harness connector. Check for continuity between following terminals: Purge solenoid valve harness connector terminal "A" and main relay 4-pin harness connector terminal "D" (White/Red wire) through common connector. Purge solenoid valve harness connector terminal "B" (Brown/Red wire) and breakout box terminal No. 67 through common connector. If continuity is present, go to next step. If continuity is not present, repair open circuit in suspect wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
3. Short Circuit Inspection Check for continuity between following: Purge solenoid valve harness connector terminal "A" and main relay 4-pin harness connector terminal "D" (White/Red wire) through common connector. Purge solenoid valve harness connector terminal "B" and breakout box terminal No. 67 (Brown/Red wire) through common connector. If continuity is present, repair short circuit in suspect wire or replace wire harness.

VARIABLE VALVE TIMING ACTUATOR

Note. On Mazda6 2.3L and 3.0L, variable valve timing actuator cannot be disassembled because it is a precision unit.

1. Disconnect the negative battery cable.
2. Remove plug hole plate.
3. Remove high-tension leads.
4. Remove Oil Control Valve (OCV) 2-pin harness connector.
5. Remove ventilation hose.
6. Remove cylinder head cover.
7. Confirm groove on rotor and notch on cover of variable valve timing actuator are aligned and fitted. (Scheme 209) If groove and notch are not aligned, turn crankshaft clockwise two rotations. Verify that groove and notch are aligned. If groove and notch are still not aligned, replace variable valve timing actuator. If, when turning crankshaft, there is a hitting noise from variable valve timing actuator each time cam passes fully lifted position, it means that variable valve timing actuator is not secured. Replace variable valve timing actuator. Refer to «VARIABLE VALVE TIMING ACTUATOR»(ref-151901-S38245530762003010900000) under VARIABLE VALVE TIMING SYSTEM in REMOVAL, OVERHAUL & INSTALLATION article.

Scheme 209

1. Remove the cylinder head cover. See VALVE COVER under REMOVAL & INSTALLATION in appropriate article in ENGINES.
2. Confirm key groove on rotor and timing mark on sprocket of variable valve timing actuator are aligned and fitted. (Scheme 210) If key groove and timing mark are not aligned, rotate crankshaft clockwise one rotation and then counterclockwise one rotation. Verify key groove and timing mark are aligned. If key groove and timing mark are still not aligned, replace variable valve timing actuator. Refer to «VARIABLE VALVE TIMING ACTUATOR»(ref-151901-S38245530762003010900000) under VARIABLE VALVE TIMING SYSTEM in REMOVAL, OVERHAUL & INSTALLATION article. If, when rotating crankshaft, there is a hitting noise from variable valve timing actuator each time cam passes fully lifted position, it means variable valve timing actuator is not secured. Replace variable valve timing actuator.

Scheme 210

Scheme 211

1. Disconnect negative battery cable.
2. Remove timing belt. See TIMING BELT under REMOVAL & INSTALLATION in appropriate article in ENGINES.
3. Hold hexagonal part of intake camshaft with an adjustable wrench to prevent camshaft from rotating. (Scheme 211) Attempt to rotate variable valve timing actuator by hand and ensure it does not move. If variable valve timing actuator moves, stopper pin in variable valve timing actuator is not operating. Replace variable valve timing actuator.
4. Install timing belt. See TIMING BELT under REMOVAL & INSTALLATION in appropriate article in ENGINES.

MISCELLANEOUS CONTROLS

Note. Although some of the controlled devices listed here are not technically engine performance components, they can affect driveability if they malfunction.

A/C Clutch Relay

For detailed A/C clutch diagnostic procedures, see appropriate MANUAL A/C-HEATER SYSTEMS or AUTOMATIC A/C HEATER SYSTEMS articles in AIR CONDITIONING & HEATING.

Single Speed Motor - Mazda6 (3.0L)

1. Ensure battery is fully charged. Disconnect cooling fan motor 2-pin harness connector from fan control module. Connect ammeter between positive battery terminal and positive terminal of fan control module 2-pin harness connector. Ground negative terminal of fan control module 2-pin harness connector. (Scheme 212)
2. Ensure cooling fan motor operates smoothly at specified standard current draw. See «COOLING FAN MOTOR CURRENT DRAW SPECIFICATIONS»(ref-151892-S35436901822003010900000) table. If cooling fan motor current draw is not as specified, replace cooling fan motor.

Scheme 212

Single Speed Motor - Miata, Protege & Protege5

1. Ensure battery is fully charged. Disconnect cooling fan motor 2-pin harness connector. Connect ammeter between positive battery terminal and positive terminal of cooling fan motor connector. (Scheme 213)or (Scheme 214). Ground negative cooling fan terminal. See appropriate WIRING DIAGRAM in ELECTRIC COOLING FANS article in ENGINE COOLING.
2. Ensure cooling fan motor operates smoothly at specified standard current draw. See «COOLING FAN MOTOR CURRENT DRAW SPECIFICATIONS»(ref-151892-S35436901822003010900000) table. If cooling fan motor current draw is not as specified, replace cooling fan motor.

COOLING FAN MOTOR CURRENT DRAW SPECIFICATIONS

Scheme 213

Scheme 214

Single Speed Motor - MPV

1. Ensure battery is fully charged. Disconnect cooling fan 2-pin harness connector from fan control module. Connect ammeter between positive battery terminal and positive terminal of fan control module 2-pin harness connector (cooling fan harness). Ground negative terminal of fan control module 2-pin harness connector (cooling fan harness). (Scheme 215)
2. Ensure cooling fan motor operates smoothly at specified standard current draw. See «COOLING FAN MOTOR CURRENT DRAW SPECIFICATIONS»(ref-151892-S35436901822003010900000) table. If cooling fan motor current draw is not as specified, replace cooling fan motor.

Scheme 215

Multiple 2 Speed Motors - Mazda6 (2.3L)

1. Ensure battery is fully charged. Disconnect cooling fan motor connector. Connect ammeter between positive battery terminal and positive cooling fan motor connector terminal for desired fan speed test. (Scheme 216), (Scheme 217) & (Scheme 218).
2. Ensure cooling fan motor operates smoothly on all speeds at specified current. See «COOLING FAN MOTOR CURRENT DRAW SPECIFICATIONS»(ref-151892-S35436901822003010900000) table. If cooling fan motor draws more or less than specified amperage, check wiring. If wiring is okay, replace cooling fan motor.

Scheme 216

Scheme 217

Scheme 218

Cooling Fan Relay

For diagnostic procedures, see appropriate MANUAL A/C-HEATER SYSTEMS or AUTOMATIC A/C HEATER SYSTEMS article in HEATING & AIR CONDITIONING or ELECTRIC COOLING FANS article in ENGINES.