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SECTION 3 - TROUBLESHOOTING DTCs

Check Voltages ---------------------------------------------------------------------------------------------------------------------------------------- 20
Check Waveforms ------------------------------------------------------------------------------------------------------------------------------------- 21

TEST PROCEDURES ------------------------------------------------------------------------------------------------------------------------------------- 22
VERIFY ENGINE CONTROL MODULE (ECM) POWERS UP --------------------------------------------------------------------------------- 23

Circuit Description - ECM Power ------------------------------------------------------------------------------------------------------------------23
Check ECM Power and Ground -------------------------------------------------------------------------------------------------------------------23
ECM Connector Loom Cover Removal ----------------------------------------------------------------------------------------------------------24

SPN 51 THROTTLE POSITION SENSOR (TPS) --------------------------------------------------------------------------------------------------25

SPN 91 SPEED LEVER ---------------------------------------------------------------------------------------------------------------------------------- 26

SPN 98 LOW OIL LEVEL -------------------------------------------------------------------------------------------------------------------------------- 30

SPN 102 MANIFOLD ABSOLUTE PRESSURE SENSOR (MAP) -----------------------------------------------------------------------------31

SPN 105 INTAKE AIR TEMPERATURE SENSOR (IAT) ---------------------------------------------------------------------------------------- 33

SPN 110 ENGINE HEAD TEMPERATURE SENSOR (EHT) -----------------------------------------------------------------------------------35

Circuit Description ------------------------------------------------------------------------------------------------------------------------------------- 35

Not for

Reproduction

Summary of Contents for 25E300

Page 1: ...Vanguard EFI Diagnostics and Repair 25E300 REPAIR MANUAL N o t f o r R e p r o d u c t i o n...

Page 2: ...ed on the data available at the time of publication Briggs Stratton reserves the right to change alter or otherwise improve the product or the product manuals at any time without prior notice Briggs S...

Page 3: ...iew the Illustrated Parts List for part availability before conducting any service work NOTE Many of the images in this document are representative of the Standard Chore engine While other engines mod...

Page 4: ...are you for the diagnostic and repair steps Diagnostic Introduction When diagnosing a specific problem with an engine or engine component first see SECTION 2 DIAGNOSTIC INTRODUCTION This section is de...

Page 5: ...INTRODUCTION 2 SECTION 3 TROUBLESHOOTING DTCs 3 SECTION 4 WIRE HARNESS SCHEMATICS AND PIN OUTS 4 SECTION 5 SYMPTOMS AND TROUBLESHOOTING GUIDE 5 SECTION 6 REMOVAL AND INSTALLATION 6 SECTION 7 SPECIFICA...

Page 6: ...1 SECTION 1 SAFETY AND GENERAL INFORMATION GENERAL SAFETY MESSAGES 8 7 N o t f o r R e p r o d u c t i o n...

Page 7: ...r if equipped are correctly installed Do not crank the engine with the spark plug removed If the engine is flooded set the choke if equipped to the OPEN or RUN position Move the throttle if equipped t...

Page 8: ...d still be exposed to dangerous carbon monoxide gas If you feel sick dizzy or weak while you use this product get to fresh air RIGHT AWAY See a doctor You may have carbon monoxide poisoning Carbon mon...

Page 9: ...hat long hair is away from all rotating parts Do not wear loose clothes or items that could become caught WARNING Fuel and its vapors are flammable and explosive Fire or explosion could result in burn...

Page 10: ...2 On Board Diagnostic OBD System Check 12 Diagnostic Trouble Codes DTCs 12 Malfunction Indicator Lamp MIL 12 Data Link Connector DLC 12 Using the Diagnostic Tool and Software to Read Clear DTCs 13 Bac...

Page 11: ...e Indicator FMI The J1939 protocol transmits each DTC in a number of parts two of which are the Suspect Parameter Number SPN and the Failure Mode Indicator FMI While the SPN indicates the source of th...

Page 12: ...selecting the icon on the desktop 2 After entering the User Name and Password click Log In NOTE If this is your first time using the Diagnostic Tool and Software refer to the Briggs Stratton EFI Diag...

Page 13: ...and or probe pin damage can occur Probe travel may be stopped by contact with insulation or core crimps Try again after removing and re positioning probe pin IMPORTANT Use care to avoid deforming con...

Page 14: ...ion 26 Possible FMIs SPN 91 26 Speed vs Voltage Table 27 SPN 91 FMI 3 Signal Voltage High 28 SPN 91 FMI 4 Signal Voltage Low Open 29 SPN 98 LOW OIL LEVEL 30 Circuit Description 30 Possible FMIs 30 SPN...

Page 15: ...rs Detected in FDI During RUN State 42 SPN 633 FMI 11 Vapors Detected in FDI During CRANKING State 42 SPN 636 CRANKSHAFT WRONG TOOTH NUMBER 43 Circuit Description 43 Possible FMIs SPN 636 43 SPN 636 F...

Page 16: ...rt Low 54 SPN 1569 ENGINE OVER TEMPERATURE WHILE RUNNING 55 Circuit Description 55 Possible FMIs SPN 1569 55 SPN 1569 FMI 16 Head Over Temperature 55 SPN 5419 ELECTRONIC THROTTLE CONTROL ETC 56 Circui...

Page 17: ...t Wrong Tooth Number 8 Additional Tooth Detected 637 Missing Crank Sensor CKP 7 Missing Crank Sensor Signal 639 CAN Bus Offline 19 Data Error 3 Voltage High Open 651 Fuel Injector 1 4 Voltage Low 3 5V...

Page 18: ...Model 25E300 EFI Component Locations 19 N o t f o r R e p r o d u c t i o n...

Page 19: ...wire at the DLC 3 Connect terminal C back probe to red meter test lead on DVOM 4 Connect black meter test lead on DVOM to ground 5 Turn Ignition ON Engine OFF 6 Compare voltage to table below 2 1 Turn...

Page 20: ...ter option can give valuable information on the health of the CAN bus The CAN electrical signals can be viewed by connecting the oscilloscope to terminal C CAN Hi and terminal D CAN Lo on the DLC Heal...

Page 21: ...h of the engine check the box in the header B to the left of Test Name This action will cause all the succeeding boxes to be checked Press Start C to automatically perform each test in the sequence sh...

Page 22: ...rey on the operator panel Perform visual and continuity check of 10 amp main fuse Red on the operator panel 2 1 Turn Ignition OFF 2 Remove probe from terminal J4 and back probe terminal M4 Yellow wire...

Page 23: ...light pressure on the loom cover use a small flat blade screwdriver to push latch B on each side of terminal end of connector outward away from connector body Do not release pressure on the loom cover...

Page 24: ...engaged to allow the engine to continue to operate with a low idle speed Possible FMIs SPN 51 The possible FMIs for SPN 51 are as follows FMI Description 2 Intermittent Fail 3 Signal Voltage High 4 Si...

Page 25: ...M that is interpreted as a commanded engine speed If the voltage exceeds 4 9 volts DC or drops below 0 1 volts DC the appropriate FMI will set NOTE The engine will default to minimum target engine spe...

Page 26: ...Speed vs Voltage Table 8 27 N o t f o r R e p r o d u c t i o n...

Page 27: ...7 Turn Ignition ON Engine OFF 8 Move the throttle control to low speed and take note of the voltage reading Voltage reading should decrease 9 Move the throttle control to high speed and take note of...

Page 28: ...ed Voltage reading should decrease 11 When the throttle was moved to low speed was the voltage less than 0 1 VDC Go to step 2 No problem currently exists Clear codes While monitoring voltage try to du...

Page 29: ...at the oil level is within the cross hatch pattern on the dipstick See A within the image below 3 Is the engine oil level low Fill engine with new oil to the proper level Start engine to verify repair...

Page 30: ...failure This barometric pressure is also used to judge ambient elevation to provide seamless engine operation at various elevations Possible FMIs SPN 102 The possible FMIs for SPN 102 are as follows...

Page 31: ...EMOVAL AND INSTALLATION Electronic Throttle Control ETC TMAP Sensor SPN 102 FMI 4 Signal Voltage Low Open Step Action Yes No 1 1 Turn Ignition OFF 2 Back probe terminal D2 White Red wire of ECM connec...

Page 32: ...s FMI Description 2 Intermittent Fail 3 Signal Voltage High Open 4 Signal Voltage Low FMI 2 Check to ensure the TMAP connector is fully mated Check wire harness for breaks loose connections and shorts...

Page 33: ...N 6 REMOVAL AND INSTALLATION Electronic Throttle Control ETC TMAP Sensor SPN 105 FMI 4 Signal Voltage Low Step Action Yes No 1 1 Turn Ignition OFF 2 Back probe terminal E4 Tan Black wire of ECM connec...

Page 34: ...head adjacent to the spark plug See image below for sensor location Possible FMIs SPN 110 The possible FMIs for SPN 110 are as follows FMI Description 2 Intermittent Fail 3 Signal Voltage High Open 4...

Page 35: ...I wire harness and is not sold separately SPN 110 FMI 4 Voltage Low Step Action Yes No 1 1 Turn Ignition OFF 2 Back probe terminal E2 Tan wire of ECM connector 3 Connect terminal E2 back probe to red...

Page 36: ...n the positive and negative posts with a DVOM determine the fault associated with the ignition circuit or charging circuit Possible FMIs SPN 158 The possible FMIs for SPN 158 are as follows FMI Descri...

Page 37: ...st lead on DVOM to ground 5 Turn Ignition ON Engine OFF 6 Does DVOM read 12 volts DC Go to step 3 Check vehicle or equipment side for problems 3 1 Check condition of 2 amp fuse in the fuse block Is fu...

Page 38: ...between the positive and negative posts with a DVOM determine the fault associated with the ignition circuit or charging circuit Possible FMIs SPN 168 The possible FMIs for SPN 168 are as follows FMI...

Page 39: ...t lead on DVOM to ground 5 Turn Ignition ON Engine OFF 6 Does DVOM read 12 volts DC Go to step 3 Check vehicle or equipment side for problems 3 1 Check condition of 10 amp fuse in the fuse panel Is fu...

Page 40: ...ne overspeed event occurs but is not actively engaging the rev limiter the fault will be stored in the ECM memory Possible FMIs SPN 190 The possible FMIs for SPN 190 are as follows FMI Description 15...

Page 41: ...blend fuel being used in a high ambient temperature environment Drain fuel and replace with new Proceed to Step 2 2 Are the air cooling passages blocked or dirty Clean all engine cooling system compon...

Page 42: ...s follows FMI Description 2 Additional Edges Detected 8 Missing or Additional Tooth Detected FMI 2 Erratic signal possibly caused by excessive air gap or electronic noise FMI 8 Abnormal frequency due...

Page 43: ...The ECM will not be able to determine which stroke the pistons are on Possible FMIs SPN 637 The possible FMIs for SPN 637 are as follows FMI Description 7 Missing Crankshaft Sensor Signal SPN 637 FMI...

Page 44: ...N bus communication is lost SPN 639 will be stored in the ECM Possible FMIs SPN 639 The possible FMIs for SPN 639 are as follows FMI Description 19 Data Error For diagnosing potential CAN BUS system p...

Page 45: ...r is faulty the technician must determine if the fault is in the control circuit from the ECM or the 12v circuit from the main power relay NOTE Injector resistance between pins 1 and 2 should be 1 8 2...

Page 46: ...t DVOM to read volts DC 7 Turn Ignition ON Engine OFF 8 Does DVOM read 12 2 13 5 volts DC Go to step 4 Reading is below 12 2 volts DC Perform visual and continuity check of 10 amp Battery fuse Red 4 1...

Page 47: ...OFF 2 Back probe using fused patch cord terminal 1 Yellow wire of fuel injector connector 3 Connect terminal 1 back probe to black meter test lead on DVOM 4 Set DVOM to read resistance 5 Turn Ignition...

Page 48: ...8 The possible FMIs for SPN 818 are as follows FMI Description 3 5V Supply High 4 5V Supply Low or Shorted to Ground 16 Over Temperature FMI 16 Over temperature of the 5 volt voltage regulator SPN 818...

Page 49: ...probe to black meter test lead on DVOM 6 Set DVOM to read volts DC 7 Turn Ignition ON Engine OFF 8 Does DVOM read 5 volts DC No current issue Go to step 2 2 1 Turn Ignition OFF 2 Disconnect ECM connec...

Page 50: ...peed 2 Engine continues to operate while monitoring the engine temperature If the engine temperature is not reduced below the overheat threshold limit SPN 1110 is triggered and the engine shuts down t...

Page 51: ...ols the ignition coil by completing the ground circuit as needed When an ignition coil fault is set the ECM also shuts down the fuel injector Possible FMIs SPN 1268 The possible FMIs for SPN 1268 are...

Page 52: ...lead on DVOM 4 Connect black meter test lead on DVOM to a known good ground 5 Set DVOM to read volts DC 6 Turn Ignition ON Engine OFF 7 Does DVOM read 12 2 13 5 volts DC Go to step 4 Reading is below...

Page 53: ...2 Back probe using fused patch cord terminal 1 Yellow wire of ignition coil connector 3 Connect terminal 1 back probe to black meter test lead on DVOM 4 Set DVOM to read resistance 5 Turn Ignition ON...

Page 54: ...Engine continues to operate while monitoring the engine temperature If the engine temperature is not reduced below the overheat threshold limit SPN 1110 is triggered and the engine shuts down to prot...

Page 55: ...e either of these conditions found Yes Clean and retest No If active SPN 5419 fault persists after cleaning replace throttle body assembly See SECTION 6 REMOVAL AND INSTALLATION Electronic Throttle Co...

Page 56: ...operate while monitoring the engine temperature If the engine temperature is not reduced below the overheat threshold limit SPN 1110 is triggered and the engine shuts down to protect from damage Possi...

Page 57: ...olenoid to engage through the control circuit If the ECM receives a start signal request from the key switch for an excessive amount of time SPN 7753 will be triggered indicating an issue with the sta...

Page 58: ...fully charged Check for power between the battery and the operator panel connector Red wire Check for power between operator panel connector and key switch connector Violet wires Check 2 Amp fuse in...

Page 59: ...4 SECTION 4 WIRE HARNESS SCHEMATICS AND PIN OUTS ECM CONNECTOR PIN OUT 61 25E300 WIRING HARNESS DIAGRAM 62 60 vanguardpower com N o t f o r R e p r o d u c t i o n...

Page 60: ...ture Sensor E3 Green Oil Level Sensor E4 Tan Black Intake Air Temperature F2 F3 Orange White Interlock Active Lo F4 White Brown Analog Throttle G2 Black Interlock Active Hi G3 G4 Pink Black Throttle P...

Page 61: ...25E300 Wiring Harness Diagram 62 vanguardpower com N o t f o r R e p r o d u c t i o n...

Page 62: ...63 N o t f o r R e p r o d u c t i o n...

Page 63: ...E INTRODUCTION 65 PRELIMINARY INSTRUCTIONS 65 ENGINE DOES NOT CRANK 66 ENGINE CRANKS BUT DOES NOT START 67 ENGINE IS HARD TO START 68 ENGINE POWER OUTPUT LOW 69 ENGINE HUNTS AND SURGES 71 64 vanguardp...

Page 64: ...y See SECTION 6 REMOVAL AND INSTALLATION Spark Plug Inspect the fuel filter condition and service if necessary See SECTION 6 REMOVAL AND INSTALLATION Fuel Filter Inspect fuel condition Replace with fr...

Page 65: ...errupt is NOT active or faulty if equipped Is a problem found Repair Go to step 6 6 Verify ignition switch is working properly See Repair Manual Is a problem found Repair Go to step 7 7 Verify starter...

Page 66: ...y if equipped Is a problem found Repair Go to step 8 8 Check battery as follows Look for loose or corroded terminals Verify battery voltage is 12 2 13 5 volts Is a problem found Repair Go to step 9 9...

Page 67: ...pump to the fuel injector Is a problem found Repair Go to step 5 5 Check battery as follows Look for loose or corroded terminals Verify battery voltage is 12 2 13 5 volts Is a problem found Repair Go...

Page 68: ...se oil Go to step 6 6 Verify air filter element is clean and dry Is a problem found Replace air filter element Go to step 7 7 Verify engine is not supporting a greater load than intended for its appli...

Page 69: ...roblems have been found proceed as follows Repeat visual check Review Diagnostic Tool Code Reader data Check all electrical connections within the suspect circuit and or system Is a problem found Repa...

Page 70: ...heck battery as follows Look for loose or corroded terminals Verify battery voltage is 12 2 13 5 volts Is a problem found Repair Go to step 6 6 Verify crankcase oil is at the correct level Is a proble...

Page 71: ...Housing Installation 78 SIDE COVER 79 Side Cover Removal 79 Side Cover Installation 79 OPERATOR PANEL 80 Operator Panel Removal 80 Operator Panel Installation 80 FUEL TANK 81 Fuel Tank Removal 81 Fuel...

Page 72: ...lation 95 IGNITION COIL 96 Ignition Coil Removal 96 Ignition Coil Installation 96 SPARK PLUG 96 Spark Plug Removal 96 Spark Plug Installation 96 CRANKSHAFT POSITION SENSOR CKP 97 Crankshaft Position S...

Page 73: ...fasteners A Figure 11 that secure the front panel to the operator s panel 11 NOTE The two fasteners that secure the front panel to the operator s panel make use of captive nuts within the front cover...

Page 74: ...rvice and replacement procedures Air Cleaner Assembly High Mount Removal 1 See Front Cover Panel Removal 2 Undo the two air cleaner cover retaining fasteners A Figure Remove cover 3 Remove the air fil...

Page 75: ...re 13 Tighten to 40 lb in 4 5 Nm 5 Start by hand the upper air cleaner fastener A Figure 12 Tighten to 95 lb in 10 7 Nm 6 Install the valve cover breather hose onto the air cleaner base port A Figure...

Page 76: ...tion of the gasket matches the profile of the air cleaner flange See Figure 18 3 Install the air cleaner assembly onto the throttle body mounting studs 4 Start by hand the two air cleaner to throttle...

Page 77: ...rewind starter on the blower housing in the position noted from removal 2 Start by hand the three rewind starter fasteners A C Figure 19 Tighten to 30 lb in 3 4 Nm 19 Blower Housing Blower Housing Re...

Page 78: ...the side cover alignment tab is located BEHIND the operator panel 2 Start by hand the two side cover to mounting bracket fasteners C D Figure 22 Tighten to 50 lb in 5 6 Nm 3 Start by hand the operator...

Page 79: ...5 Remove the operator panel from the engine and set aside Operator Panel Installation 1 Connect the key switch harness connector A Figure 25 to the key switch at the rear of the panel Press onto key s...

Page 80: ...ing the engine until the tank is empty 2 Remove front cover panel See Front Cover Panel Removal 3 Starting at the front of the engine blower housing side remove the front fuel tank fastener A Figure 2...

Page 81: ...emaining fuel in the proper receptacle Fuel Tank Installation 1 Orient the fuel tank so that the side with the mounting studs faces the starter motor side of the engine 2 Connect the fuel supply hose...

Page 82: ...dispose of in the appropriate receptacle 4 Disconnect the fuel supply hose from the fuel pump A Figure 31 Squeeze the tangs of the hose clamp and slide the clamp along the hose away from the pump Usi...

Page 83: ...pply hose onto the fuel filter port until the end of the hose meets the port flange D Figure 31 7 Squeeze the tangs of the fuel hose clamp and slide hose clamp over the fuel filter port until it is 1...

Page 84: ...On some engines with a remote fuel tank the fuel return hose can be routed underneath the cylinder head air guide Feed the fuel hose underneath the air guide to remove from engine Fuel Return Hose Ins...

Page 85: ...ove the crankcase port and 1 8 inch 3mm from the end of the hose 4 Connect the end of the pulse hose to the fuel pump A Figure 34 Press the hose onto the fuel pump port until the hose end contacts the...

Page 86: ...arness until it reaches the vent port on the ETC assembly 3 Press the vent hose onto the ETC port until the end of the hose contacts the port flange A Figure 36 4 Connect the vent hose to the remote f...

Page 87: ...Model 25E300 Fuel Hose Location and Routing With Tank 88 vanguardpower com N o t f o r R e p r o d u c t i o n...

Page 88: ...Model 25E300 Fuel Hose Location and Routing Tankless 89 N o t f o r R e p r o d u c t i o n...

Page 89: ...l in the proper receptacle 6 Remove the two fasteners that secure the fuel pump to the mounting bracket D Remove the fuel pump from the bracket and set aside Mechanical Fuel Pump Installation 1 Instal...

Page 90: ...f each hose NOTE Depending on your engine s trim a remote fuel tank may be equipped In this instance a second fuel filter between the fuel tank and the fuel pump on the fuel supply hose D Figure 39 ma...

Page 91: ...h mating surfaces meet Rotate if necessary the injector so that the mounting bracket holes align with the mounting holes on the throttle body NOTE Make sure the fuel injector is orientated in the corr...

Page 92: ...N Using the Diagnostic Tool and Software 2 Click on the Flash icon A Figure 44 in the left menu of the Diagnostic Tool Software dashboard 3 Click the Scan New Injector box B on the Flash dashboard 4 C...

Page 93: ...on Fuel Line Removal Tool 4 Disconnect the TMAP sensor electrical connector from the top of the throttle body housing B Pull out the red lock tab and then depress the release tab while pulling the con...

Page 94: ...wire harness electrical connector to the TMAP sensor connector at the top of the throttle body B 7 If equipped connect the fuel vent hose to the port on the throttle body C TMAP Sensor Removal 1 See F...

Page 95: ...fastener B Tighten to 95 lb in 10 7 Nm 4 Start by hand the upper ignition coil air cleaner fastener A Figure 52 Tighten to 95 lb in 10 7 Nm 5 Install the ignition coil electrical connector A Figure 5...

Page 96: ...p tighten the two sensor fasteners in the sequence shown in Figure 55 to 28 lb in 3 2 Nm 5 Connect the wire harness connector to the crankshaft position sensor electrical connector Engine Head Tempera...

Page 97: ...on the operator panel See Figure in Operator Panel Removal 10 Remove the lower side cover fastener to release the side cover from the mounting bracket Remove side cover from engine and set aside 11 R...

Page 98: ...ng See Blower Housing Installation 6 Install the ETC onto the cylinder head See Electronic Throttle Control ETC 7 Connect the TMAP harness connector to the sensor D Figure 60 Press connector until it...

Page 99: ...g the tab and then pivoting the latch down A Figure 62 to release the connector 62 4 Remove the four ECM fasteners B NOTE A ring terminal from the main engine harness is mounted behind the upper right...

Page 100: ...diagnostic tool software and update the ECM and fuel injector calibration Failure to update the new ECM with the most current calibration and the fuel injector calibration may cause engine performance...

Page 101: ...7 SECTION 7 SPECIFICATIONS ENGINE SPECIFICATIONS 103 TORQUE SPECIFICATIONS 104 102 vanguardpower com N o t f o r R e p r o d u c t i o n...

Page 102: ...l Fuel Tank Capacity 6 4 qt 6 1 L Ignition Timing Variable Crank Position Sensor CKP Air Gap 0 010 0 015 in 0 25 0 38 mm Spark Plug Gap 0 030 in 0 76 mm Valve Clearance Intake 0 004 0 006 in 0 10 0 15...

Page 103: ...Panel Upper Fastener Low Mount or Remote Air Cleaner 50 lb in 5 6 Nm Fuel Injector to Throttle Body 13 lb in 1 5 Nm Fuel Tank Front of Engine Fastener 160 lb in 18 Nm Fuel Tank Rear of Engine Fastene...

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