Engine Controls - Basic Testing - 3.2L: Other Honda Passport I

TERMINOLOGY

Due to Federal government requirements, manufacturers may use names and acronyms for systems and components different than those used in previous years. The following table will help eliminate confusion when dealing with these components and systems.

SAE TERMINOLOGY

Compression

Check engine mechanical condition with a compression gauge, vacuum gauge, or an engine analyzer. See engine analyzer manual for specific instructions.

Exhaust System Backpressure

The exhaust system can be checked with a vacuum or pressure gauge. If using a pressure gauge, remove oxygen sensor or air injection check valve (if equipped). Connect a 0-5 psi pressure gauge and run engine at 2000 RPM. If exhaust system backpressure is greater than 1 3/4 - 2 psi, exhaust system or catalytic converter is plugged.

If a vacuum gauge is used, connect vacuum gauge hose to intake manifold vacuum port and start engine. Observe vacuum gauge. Open throttle part way and hold steady. If vacuum gauge reading slowly drops after stabilizing, check exhaust system for restriction.

FUEL SYSTEM

FUEL SYSTEM PRESSURE RELEASE

Note. Fuel pump relay is located in engine compartment fuse/relay box.

1. Loosen fuel tank filler cap to relieve tank pressure. Remove fuel pump relay from underhood fuse/relay box. Start and operate engine until it stalls. Crank engine an additional 30 seconds.
2. Loosen hose clamp of fuel line on side of pressure regulator, coming from fuel line inlet distributor pipe. Cover fuel hose with a shop towel, and slowly pull hose from pressure regulator to relieve fuel pressure. When fuel stops leaking, reinstall hose and clamp.

Fuel Pressure

1. Relieve fuel pressure. See «FUEL SYSTEM PRESSURE RELEASE»(ref-15973-S29140308122000122900000) . Attach Fuel Pressure Gauge Set (J-34730-1 ) and Adapter (J-35957-1 ) to Schrader fitting on fuel rail. Disconnect pressure regulator vacuum hose. Turn ignition on. Allow fuel pump to run for about 2 seconds.
2. Fuel system pressure should be about 41-46 psi (2.8-3.2 kg/cm 2 ). See «FUEL PUMP PERFORMANCE»(ref-15973-S38848510952000122900000) . Start engine and check for leaks. Connect pressure regulator vacuum hose. If engine will not start, the fuel pump relay can be by-passed. Also see appropriate «CHART A-3 - ENGINE CRANKS BUT WILL NOT RUN»(ref-15973-S27526126972000122900000) under TROUBLE SHOOTING CHARTS. With engine idling, fuel pressure should be 25-30 psi (1.8-2.1 kg/cm 2 ). NOTE: To test the fuel pump relay circuit, proceed to «CHART A-5 - FUEL PUMP RELAY CIRCUIT»(ref-15973-S19453073932000122900000) under TROUBLE SHOOTING CHARTS.

Fuel Pump Relay

1. ECM supplies power to relay as long as ECM receives ignition reference signals or starter crank signal. To run fuel pump without starting engine, remove relay and jumper terminals No. 2 and 4. (Scheme 92)and (Scheme 93).
2. To test relay, use jumper wires to ground terminal No. 4 of relay and apply battery voltage to terminal No. 2 of relay. Using ohmmeter, check for continuity between relay terminals No. 1 and 3. If continuity is not present, replace relay. FUEL PUMP PERFORMANCE Engine At Idle W/O Vacuum psi (kg/cm 2 ) At Idle W/ Vacuum psi (kg/cm 2 ) 3.2L (1) 41-46 (2.8-3.2) (2) 25-30 (1.8-2.1) (1) With ignition on and vacuum hose disconnected from pressure regulator. (2) With engine at idle or with 12-14 in. Hg vacuum manually applied to pressure regulator.

Ignition System Check

See appropriate CHART C-4, under TROUBLE SHOOTING CHARTS, starting with CHART C-4D-1 - IGNITION SYSTEM CHECK .

Ignition Coil

Information is not available from manufacturer.

Crankshaft Position Sensor

Information is not available from manufacturer.

IDLE SPEED & IGNITION TIMING

For adjustment procedures, see ADJUSTMENTS - 3.2L article.

IDLE SPEED SPECIFICATIONS

BASE IGNITION TIMING

CHART A-3 - ENGINE CRANKS BUT WILL NOT RUN

Note. Before performing this test, check battery condition, engine cranking speed and tank for adequate fuel. Test numbers refer to numbers on diagnostic chart.

Scheme 88

Scheme 89

Scheme 90

Scheme 91

1. When ignition is turned on, the CHECK ENGINE light should come on, indicating battery voltage and ignition voltage are being supplied to ECM. If NO DLC data (trouble codes) are displayed on the scan tester, this may be due to an ECM problem. Refer to the «TESTS W/CODES - 3.2L»(ref-15969) article to diagnose CHECK ENGINE light. If TP sensor voltage is more than 2.5 volts, engine may be in "clear flood" mode, which will cause starting problems. Engine will not start without ignition reference signals. Scan tester should indicate engine speed (RPM) during cranking.
2. Because electronic ignition system uses 2 plugs and wires to complete circuit of each coil, opposite spark should be left connected. If RPM is indicated during cranking, ignition control module is receiving crank signal. If no spark is present, ignition control module is not triggering coils. See «IGNITION CHECKS»(ref-15973-S21963173932000122900000) to diagnose ignition problems related to no-spark condition.
3. Test light should blink, indicating ECM is in control of injectors. Brightness of light is not important.
4. This test checks ignition control module reference pulses, wiring and ECM. Using test light connected to 12-volt source, momentarily touch Yellow / Red wire. A reference pulse should be generated. If RPM is indicated, ECM and wiring are okay.
5. High resistance in spark plug wire could cause a no-start condition. If a spark plug wire is faulty, replace wire and retest system.
6. This test will check injector harness for an open or shorted circuit after engine harness connector.
7. A shorted or open injector could be cause of engine cranks but will not run symptom.
8. Test for short to ground in injector driver circuits.
9. Check for voltage at injector. An open in Red/Green wire at splice from main relay would result in engine cranks but will not run symptom.
10. Test engine control module for injector pulse.
11. A faulty resistor module could be cause of no-start condition. If module is faulty, recheck engine control module after replacing resistor module.
12. This test will determine if 12-volt supply and good ground are available at ignition control module.
13. This test checks for battery voltage in ignition feed circuit to ignition control module.
14. This test checks for continuity of crankshaft position sensor and connections.
15. Voltage will vary depending on engine cranking speed.

CHART A-5 - FUEL PUMP RELAY CIRCUIT

When ignition switch is turned to ON position, ECM activates fuel pump relay to run fuel pump. ECM activates relay as long as it receives ignition reference signals or starter crank signal. If no reference signals are received by ECM within 2 seconds after ignition is turned on, ECM cuts off power to relay.

Note. Test numbers refer to numbers on diagnostic chart.

Scheme 92

Scheme 93

1. This test checks for battery voltage at switching portion of fuel pump relay.
2. This determines if circuit between fuel pump relay (including fuel pump) and ground are okay.
3. This test will check relay circuit for availability of voltage to relay coil.

CHART C-4D-1 - IGNITION SYSTEM CHECK

Note. Test numbers refer to numbers on diagnostic chart.

Scheme 94

Scheme 95

1. If engine misfire occurs under load only, see «CHART C-4D-2»(ref-15973-S27085210222000122900000) . Engine speed should drop equally on all plug leads.
2. A spark tester must be used to verify adequate available secondary voltage at spark plug.
3. If spark jumps test gap after grounding opposite plug wire, excessive resistance exists in plug that was by-passed. A faulty or poor connection at plug may also result in a miss condition. Check for carbon deposits inside spark plug boot.
4. If carbon tracking is evident, replace coil and ensure plug wires relating to that coil are clean and tight. Excessive wire resistance or faulty connections may have damaged coil.
5. If no-spark condition follows suspected coil, that coil is faulty. Otherwise, ignition control module is cause of no spark. This test may also be performed by substituting a known-good coil for one causing no-spark condition.

CHART C-4D-2 - IGNITION SYSTEM CHECK

Note. Test numbers refer to numbers on diagnostic chart.

Scheme 96

1. If engine misfiring occurs during idle, refer back to «CHART C-4D-1 - IGNITION SYSTEM CHECK»(ref-15973-S30246747472000122900000) . A spark tester must be used to verify adequate available secondary voltage at spark plug. Spark should jump test gap on all 4 leads. This simulates a load condition.
2. If spark jumps test gap after grounding opposite plug wire, excessive resistance exists in plug that was by-passed. A faulty or poor connection at plug may also result in a miss condition. Check for carbon deposits inside spark plug boot.
3. If carbon tracking is evident, replace coil and ensure plug wires relating to that coil are clean and tight. Excessive wire resistance or faulty connections may have damaged coil.
4. If no-spark condition follows suspected coil, that coil is faulty. Otherwise, ignition control module is cause of no spark. This test may also be performed by substituting a known-good coil for one causing no-spark condition.

SUMMARY

If no faults were found while performing BASIC DIAGNOSTIC PROCEDURES, proceed to TESTS W/CODES - 3.2L article. If no hard codes are found in self-diagnostics, proceed to the TESTS W/O CODES - 3.2L article for diagnosis by symptom (i.e., ROUGH IDLE, NO START, etc.) or intermittent diagnostic procedures.