Engine Controls - Tests W/codes - 3.2L: Diagnosis Honda Passport I

TROUBLE CODE DEFINITION

CODE IDENTIFICATION

DIAGNOSTIC CIRCUIT CHECK

SCAN DATA

Diagnostic circuit check will identify problem created by Electronic Engine Control System (EECS) malfunction. It is the starting point for diagnosis. This check will direct you to the next logical step in diagnosing the complaint.

After completing diagnostic circuit check and finding on-board diagnostics functioning properly with no trouble codes displayed, use appropriate SCAN DATA table for comparison. Data values must be taken under these conditions

1. Engine at normal operating temperature.
2. Engine running at idle.
3. Vehicle in Park or Neutral.
4. System in closed loop.

The values are an average of displayed values recorded from normal operating vehicles. Values represent what a normal functioning system would typically display.

Note. Only parameters supplied by manufacturer are used in this article. If a scan tester reads other parameters, values are not recommended by manufacturer for diagnostic use. A scan tester displaying faulty data should not be used, or misdiagnosis will occur. Report problem to scan tester manufacturer.

Note. Test numbers refer to numbers on diagnostic chart.

1. This step checks if ECM can provide a ground path for CHECK ENGINE light. This is a bulb check.
2. This step checks if ECM can perform internal diagnostics.
3. This step checks if ECM can supply serial data for scan tester.
4. This step verifies scan data.
5. This step checks whether ECM or electrical system is cause of no start.
6. This step checks ECM memory for codes to aid in diagnosis.

Scheme 56

Diagnostic Aids - Engine Runs Okay

Check for faulty light bulb, open in light driver circuit or defective fuse. This will result in no oil indicator light, alternator light, seat belt reminder light, etc.

Diagnostic Aids

Normal scan tester voltage varies between .1 and 1.0 volt while in closed loop. Code 13 sets in about 40 seconds if voltage remains between .35 and .55 volt, but system will enter open loop in about 15 seconds. For intermittent inspection, see INTERMITTENTS in TESTS W/O CODES - 3.2L article.

Code 13 - Schematic (3.2L Passport Oxygen Sensor (Open Circuit). Scheme 57

Code 13 - Diagnostic Flowchart (3.2L Passport Oxygen Sensor (Open Circuit). Scheme 58

After engine is started, temperature should rise steadily to about 194°F (90°C), and then stabilize when thermostat opens. When a Code 14A is set, ECM will turn on engine cooling fan. Code 14A will set if circuit is shorted to ground. For intermittent inspection, see INTERMITTENTS in TESTS W/O CODES - 3.2L article.

Code 14A - Schematic (3.2L Passport CTS Circuit (High Temperature Indicated). Scheme 59

Code 14A - Diagnostic Flowchart (3.2L Passport CTS Circuit (High Temperature Indicated). Scheme 60

After engine is started, temperature should rise steadily to about 194°F (90°C), then stabilize when thermostat opens. Code 14B will set if sensor circuits are open. Check terminals at sensor for good contact. For intermittent inspection, see INTERMITTENTS in TESTS W/O CODES - 3.2L article.

Code 14B - Diagnostic Flowchart (3.2L Passport CTS Circuit (Low Temperature Indicated). Scheme 61

The scan tester reads throttle position in volts. With ignition on, reading should be less than 1.25 volts with throttle closed. Voltage should increase at a steady rate as throttle is moved toward WOT. An open in circuit or a short to voltage will result in Code 21A. For intermittent inspection, see INTERMITTENTS in TESTS W/O CODES - 3.2L article.

Code 21A - Schematic (3.2L Passport TPS Circuit (Signal Voltage High). Scheme 62

Code 21A - Diagnostic Flowchart (3.2L Passport TPS Circuit (Signal Voltage High). Scheme 63

A scan tester reads throttle position in volts. With ignition on, reading should be less than one volt with throttle closed. Voltage should increase at a steady rate as throttle is moved toward WOT. An open or short to ground in circuits will cause Code 21B to set. For intermittent inspection, see INTERMITTENTS in TESTS W/O CODES - 3.2L article.

Code 21B - Diagnostic Flowchart (3.2L Passport TPS Circuit (Signal Voltage Low). Scheme 64

An open in circuit will cause Code 23A to set. For intermittent inspection, see INTERMITTENTS in TESTS W/O CODES - 3.2L article.

Code 23A - Schematic (3.2L Passport MAT Circuit (Low Temperature Indicated). Scheme 65

Code 23A - Diagnostic Flowchart (3.2L Passport MAT Circuit (Low Temperature Indicated). Scheme 66

A Code 23B will set if circuit becomes open or shorted to ground. For intermittent inspection, see INTERMITTENTS in appropriate TESTS W/O CODES - 3.2L article.

Code 23B - Diagnostic Flowchart (3.2L Passport MAT Circuit (High Temperature Indicated). Scheme 67

A scan tester should indicate vehicle speed whenever vehicle is in motion. A faulty or misadjusted Park/Neutral switch can result in a false Code 24. Use scan tester to check for proper signal while vehicle is in Drive position. For intermittent inspection, see INTERMITTENTS in TESTS W/O CODES - 3.2L article.

Code 24 - Schematic (3.2L Passport VSS Circuit. Scheme 68

Code 24 - Diagnostic Flowchart (3.2L Passport VSS Circuit. Scheme 69

A sluggish oxygen sensor can cause a false Code 32 to set. If EGR valve passage is restricted, Code 32 may set.

Code 32 - Schematic (3.2L Passport EGR System. Scheme 70

Code 32 - Diagnostic Flowchart (3.2L Passport EGR System. Scheme 71

An open in circuit will cause Code 33A to set. If circuit to signal terminal is shorted to voltage, or circuit is shorted to circuit voltage, Code 33A will set. With ignition on and engine off, manifold pressure is equal to atmospheric pressure and voltage will be high. For intermittent inspection, see INTERMITTENTS in TESTS W/O CODES - 3.2L article.

Code 33A - Schematic (3.2L Passport MAP Sensor (Signal Voltage High). Scheme 72

Code 33A - Diagnostic Flowchart (3.2L Passport MAP Sensor (Signal Voltage High). Scheme 73

An open in ground circuit will cause Code 33B to set. If circuit is shorted to voltage, Code 33B will set. With ignition on and engine off, manifold pressure is equal to atmospheric pressure and voltage will be high. For intermittent inspection, see INTERMITTENTS in TESTS W/O CODES - 3.2L article.

Code 33B - Diagnostic Flowchart (3.2L Passport Map Sensor (Signal Voltage Low). Scheme 74

If Code 42 is stored and hard start problem occurs, problem is probably a grounded EST circuit. For intermittent inspection, see INTERMITTENTS in TESTS W/O CODES - 3.2L article.

Code 42 - Schematic (3.2L Passport EST (Electronic Spark Timing). Scheme 75

Code 42 - Diagnostic Flowchart (3.2L Passport EST (Electronic Spark Timing). Scheme 76

Using scan tester, observe block learn values at different RPM. Scan tester also reads block cells, so block learn values can be checked in each of the cells to determine when Code 44 may have been set. If conditions for Code 44 are present, block learn values will be about 150.

1. Oxygen sensor pigtail may be mispositioned and contacting exhaust manifold.
2. Check for intermittent ground in wire between connector and sensor.
3. An output causing ECM to sense a higher than normal vacuum will cause system to go lean. Disconnect MAP sensor. If lean condition is gone, replace sensor.
4. Water near the in-tank fuel pump inlet can be delivered to the injectors, causing a lean exhaust. This can set Code 44.
5. Fuel system will be lean if pressure is too low. Monitor fuel pressure while driving vehicle at various speeds and/or loads to confirm a problem (if necessary). Verify correct fuel injectors are installed in vehicle.
6. If there is an exhaust leak, outside air can be pulled into the exhaust and past the sensor. Vacuum or crankcase leaks can also cause a lean condition.
7. If the above are okay, problem is a faulty oxygen sensor. For intermittent inspection, see INTERMITTENTS in appropriate «TESTS W/CODES - 3.2L»(ref-15969) article.

Code 44 - Schematic (3.2L Passport Oxygen Sensor (Lean Fuel Mixture). Scheme 77

Code 44 - Diagnostic Flowchart (3.2L Passport Oxygen Sensor (Lean Fuel Mixture). Scheme 78

Code 45 or rich exhaust is most likely caused by one of the following

1. Check for fuel-contaminated oil.
2. If an open exists in ground circuit, HEI-induced electrical noise may result, causing simulated reference pulses to be picked up by ECM. Additional pulses result in a higher than actual engine speed signal. The ECM will increase injector pulse width to match fuel requirements of increased RPM signal. Tachometer will show higher than actual RPM, which can help in diagnosing this problem.
3. Check charcoal canister for fuel saturation. If full of fuel, check canister control and hoses.
4. An output causing ECM to sense a higher than normal vacuum can cause system to go rich. Disconnecting MAP sensor allows ECM to set a fixed value for the sensor. If rich condition is gone with MAP sensor disconnected, replace sensor.
5. An intermittent TPS output causes system to go rich due to a false acceleration indication.
6. Inspect oxygen sensor for silicone contamination from fuel, or use of improper RTV sealant. Sensor may have a White powdery coating and result in a high but false signal voltage (rich exhaust). ECM will reduce amount of fuel delivered to engine, causing a severe surge driveability problem.
7. Check for EGR valve sticking open at idle, usually accompanied by a rough idle or stall complaint, especially at idle. For intermittent inspection, see appropriate INTERMITTENTS in TESTS W/O CODES - 3.2L article.

Code 45 - Diagnostic Flowchart (3.2L Passport Oxygen Sensor (Rich Fuel Mixture). Scheme 79