Starting System: Overview — Mercury Mariner II (2007-2010)

Normal Operation

Under normal operation, constant power is supplied to the starter motor relay on circuit SBB11 (BU/RD). When the ignition switch is turned in the START position and held, power is then supplied to the digital transmission range (TR) sensor (automatic transaxle) or clutch cutoff switch (manual transaxle) through circuit CE619 (BU/BN), with the vehicle in PARK or NEUTRAL or clutch pedal depressed power flows to the starter motor relay through CDC37 (GY/VT). A ground is supplied through circuit CDC12 (YE) from the PCM causing the starter motor relay coil to energize and the relay contacts close. This allows power to be supplied from the starter motor relay contacts which then flows through circuit CDC25 (BN/GN) to the starter solenoid. The solenoid is grounded at the starter motor. Energizing the starter solenoid will engage the starter drive into the ring gear and closes the solenoid contacts, allowing power directly from the battery through circuit SDC02 (RD) to the starter motor to start the engine.

This pinpoint test is intended to diagnose the following

Battery
Anti-theft system
Starter relay
Ignition switch
Circuitry
TR sensor (automatic transaxle)
Clutch cutoff switch (manual transaxle)
PCM
Start diode

Scheme 3

Scheme 3: PINPOINT TEST A: THE ENGINE DOES NOT CRANK

Scheme 4

Scheme 5

Scheme 6

Scheme 7

Scheme 8

Scheme 9

Scheme 10

Scheme 11

Scheme 12

Scheme 13

Scheme 14

Scheme 15

Scheme 16

Scheme 17

A1 CHECK THE BATTERY Check the battery condition and charge. Refer to «BATTERY, MOUNTING AND CABLES»(ref-292182) article. Is the battery OK? YES : Go to A2 . NO : CHARGE or INSTALL a new battery as necessary. REFER to «BATTERY, MOUNTING AND CABLES»(ref-292182) article. TEST the system for normal operation.
A2 CHECK FOR PASSIVE ANTI-THEFT SYSTEM (PATS) DTCs NOTE: PATS system DTCs are the only DTCs of concern in this step. Only repair retrieved non-PATS DTCs if a customer concern is reported. Check for PATS DTCs. Were any PATS DTCs retrieved? YES : REFER to «ANTI-THEFT - PASSIVE ANTI-THEFT SYSTEM (PATS)»(ref-292186) article to diagnose the PATS DTCs. NO : Go to A3 .
A3 CHECK THE BATTERY GROUND CABLE Measure the voltage between the positive battery post and the battery ground cable connection at the engine. Is the voltage greater than 10 volts? YES : Go to A4 . NO : INSTALL a new battery ground cable. REFER to «BATTERY, MOUNTING AND CABLES»(ref-292182) article. TEST the system for normal operation.
A4 CHECK STARTER MOTOR GROUND Measure the voltage between the positive battery post and the starter motor case. Is the voltage greater than 10 volts? YES : Go to A5 . NO : CLEAN the starter motor mounting flange and make sure the starter motor is correctly mounted. TEST the system for normal operation.
A5 CHECK THE POWER SUPPLY TO THE STARTER MOTOR Measure the voltage between starter motor C197A, circuit SDC02 (RD) and ground. Is the voltage greater than 10 volts? YES : Go to A6 . NO : INSTALL a new positive battery cable. REFER to «BATTERY, MOUNTING AND CABLES»(ref-292182) article. TEST the system for normal operation.
A6 CHECK THE STARTER MOTOR B-PIN Connect one end of a fused (30A) jumper wire to starter motor C197A, circuit SDC02 (RD). Momentarily connect the other end of the jumper to starter motor C197B, circuit CDC25 (BN/GN). Did the starter motor engage and the engine crank? YES : Go to A7 . NO : INSTALL a new starter motor. REFER to «Starter Motor - 2.3L»(ref-292202-S42645210382008073100000) or «Starter Motor - 3.0L»(ref-292202-S16574653852008073100000) . TEST the system for normal operation.
A7 CHECK STARTER MOTOR RELAY POWER CAUTION: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector. Disconnect: Starter Motor Relay Measure the voltage between battery junction box (BJB) starter motor relay pin 3, circuit SBB11 (BU/RD), harness side and ground. Is the voltage greater than 10 volts? YES : Go to A8 . NO : REPAIR circuit SBB11 (BU/RD). TEST the system for normal operation.
A8 CHECK STARTER MOTOR RELAY Carry out the Starter Motor Relay Component Test. Refer to appropriate COMPONENT TESTING article. Did the starter motor relay pass the component test? YES : Go to A9 . NO : INSTALL a new starter motor relay. TEST the system for normal operation.
A9 CHECK THE CIRCUIT TO THE STARTER MOTOR Key in OFF position. Disconnect: Starter Motor Solenoid C197b Measure the resistance between starter motor solenoid S-terminal C197b, circuit CDC25 (BN/GN), harness side and the BJB starter motor relay pin 5, circuit CDC25 (BN/GN), harness side. Is the resistance less than 5 ohms? YES : Go to A10 . NO : REPAIR circuit CDC25 (BN/GN). TEST the system for normal operation.
A10 CHECK CIRCUIT CDC35 (BU/WH) FOR VOLTAGE Connect: Starter Motor Solenoid C197b Connect: Starter Motor Relay Disconnect: Starter Diode Measure the voltage between BJB starter diode cell, circuit CDC35 (BU/WH) and ground with the ignition switch in the START position. Is the voltage greater than 10 volts? YES : Go to A13 . NO : Go to A11 .
A11 CHECK CIRCUIT SBB27 (BU/RD) FOR VOLTAGE Disconnect: Ignition Switch C250 Measure the voltage between ignition switch C250-4, circuit SBP27 (BU/RD), harness side and ground. Is the voltage greater than 10 volts? YES : Go to A12 . NO : REPAIR circuit SBP27 (BU/RD). TEST the system for normal operation.
A12 CHECK THE IGNITION SWITCH Carry out the Ignition Switch Component Test. Refer to appropriate COMPONENT TESTING article. Did the ignition switch pass the component test? YES : REPAIR circuit CDC35 (BU/WH) for an open. TEST the system for normal operation. NO : INSTALL a new ignition switch. REFER to «STEERING COLUMN SWITCHES»(ref-292189) article. TEST the system for normal operation.
A13 CHECK THE STARTER DIODE Carry out a Starter Diode test. Is the starter diode open or shorted? YES : INSTALL a new starter diode. TEST the system for normal operation. NO : Go to A14 .
A14 CHECK THE START SIGNAL TO THE STARTER MOTOR RELAY Connect: OTIS Diode Disconnect: Starter Motor Relay NOTE: For manual transaxle, fully disengage the clutch. Measure the voltage between the BJB starter motor relay pin 2, circuit CDC37 (GY/VT), harness side and ground with the ignition switch in the START position. Is the voltage greater than 10 volts? YES : Go to A15 . NO : For automatic transaxle, go to A16 . For manual transaxle, go to A20 .
A15 CHECK CIRCUIT CDC12 (YE) FOR AN OPEN Disconnect: PCM C175B Measure the resistance between the BJB starter relay pin 1, circuit CDC12 (YE), harness side and PCM C175B-2, circuit CDC12 (YE), harness side. Is the resistance less than 5 ohms? YES : INSTALL a new PCM. REFER to «ELECTRONIC ENGINE CONTROLS - 2.3L»(ref-292203) article or «ELECTRONIC ENGINE CONTROLS - 3.0L (4V)»(ref-292224) article. NO : REPAIR circuit CDC12 (YE). TEST the system for normal operation.
A16 CHECK THE LINKAGE ADJUSTMENT Key in OFF position. Check the Transaxle Linkage Adjustment. Refer to «AUTOMATIC TRANSAXLE/TRANSMISSION EXTERNAL CONTROLS - CD4E»(ref-292225) article. Is the linkage adjustment OK? YES : Go to A17 . NO : ADJUST the linkage. TEST the system for normal operation.
A17 VERIFY THE TR SENSOR ADJUSTMENT Verify the TR Sensor Adjustment. Refer to «AUTOMATIC TRANSAXLE/TRANSMISSION - CD4E»(ref-292152) article. Does the TR sensor need adjustment? YES : ADJUST the TR sensor. TEST the system for normal operation. NO : Go to A18 .
A18 CHECK THE VOLTAGE TO THE TR SENSOR Disconnect: TR Sensor C167 Key in START position. Measure the voltage between TR sensor C167-4, circuit CE619 (BU/BN), harness side and ground with the ignition switch in the START position. Is the voltage greater than 10 volts? YES : Go to A19 . NO : REPAIR circuit CE619 (BU/BN) from the TR sensor to the BJB. TEST the system for normal operation.
A19 CHECK THE CIRCUIT BETWEEN THE TR SENSOR AND THE STARTER MOTOR RELAY Key in OFF position. Measure the resistance between TR sensor C167-9, circuit CDC37 (GY/VT), harness side and the BJB starter motor relay pin 2, circuit CDC37 (GY/VT) harness side. Is the resistance less than 5 ohms? YES : INSTALL a new TR sensor. REFER to «AUTOMATIC TRANSAXLE/TRANSMISSION - CD4E»(ref-292152) article. TEST the system for normal operation. NO : REPAIR circuit CDC37 (GY/VT). TEST the system for normal operation.
A20 CHECK THE VOLTAGE TO THE CLUTCH CUTOFF SWITCH Key in OFF position. Disconnect: Clutch Cutoff Switch C2072 Key in START position. Measure the voltage between clutch cutoff switch C2072-1, circuit CE619 (BU/BN), harness side and ground with the ignition switch in the START position. Is the voltage greater than 10 volts? YES : Go to A21 . NO : REPAIR the circuit CE619 (BU/BN) from the clutch cutoff switch to the BJB. TEST the system for normal operation.
A21 CHECK THE CIRCUIT BETWEEN THE CLUTCH CUTOFF SWITCH AND THE STARTER MOTOR RELAY Key in OFF position. Measure the resistance between clutch cutoff switch C2072-2, circuit CDC37 (GY/VT), harness side and the BJB starter motor relay pin 2, circuit CDC37 (GY/VT) harness side. Is the resistance less than 5 ohms? YES : INSTALL a new clutch cutoff switch. TEST the system for normal operation. NO : REPAIR circuit CDC37 (GY/VT). TEST the system for normal operation.

When the ignition switch is turned in the START position and released, the PCM receives a starter motor request (SMR) signal through circuit CDC35 (BU/WT). Power is then supplied from the PCM to the digital transmission range (TR) sensor on circuit CE619 (BU/BN), with the vehicle in PARK power flows through to the starter motor relay through circuit CDC37 (GY/VT). A ground is supplied through circuit CDC12 (YE) from the PCM causing the starter motor relay coil to energize and the relay contacts close. This allows power from starter motor relay through circuit CDC25 (BN/GN) to the starter solenoid. The solenoid is grounded at the starter motor. Energizing the starter solenoid will engage the starter drive into the ring gear and closes the solenoid contacts allowing power directly from the battery through circuit SDC02B (RD) to the starter motor to start the engine. The customer is no longer in the loop after the initial crank request, the customer may release the key to the RUN/START position. The PCM will disengage the starter motor based on engine running (RPM threshold), a set crank time has been exceeded or the ignition switch has been turned to the OFF position.