Hyundai TSB 98-30-002 Sonata 1998 Engine Vacuum

Hyundai TSB 98-30-002 Sonata 1998 Engine Vacuum

ENHANCED EVAPORATIVE EMISSION CONTROL SYSTEM DIAGNOSIS AND REPAIR

DESCRIPTION:

This bulletin provides information for 1998 model year system operation and diagnosis/repair methods for enhanced evaporative emission systems.

Contents

New for 1998

Quick Reference Troubleshooting

Connecting the vehicle to HDS

Using the scanner to activate the EVAP Self-Check

Graph #1: Example of 1998 Elantra Full Fuel Tank - Good Plot

Graph #2: Example of 1998 Elantra Empty Fuel Tank - Good Plot
Example of 1997 DOHC/1998 Accent Full Fuel Tank - Good Plot

Graph #3: Example of 1996/97 Elantra Full Fuel Tank - Good Plot
Example of 1997 DOHC/1998 Accent Empty Fuel Tank - Good Plot,

Graph #4: Example of 1996/97 Elantra Empty Fuel Tank - Good Plot

Graph #5: Example of 1998 Elantra Too Full Fuel Tank-Inaccurate Plot

Troubleshooting and Repair (Detailed) 1998 Sonata, 1998 Elantra

Component Troubleshooting, CCV, CPV, FVV

Schematic #1: 1998 Elantra EVAP System

Schematic #2: 1996/97 Elantra EVAP System

Schematic #3: 1997 DOHC/1998 Accent EVAP System

Schematic #4: 1998 Sonata EVAP System

New for 1998 Elantra/Tiburon:

1998 vehicles introduced the On-Board Refueling Vapor Recovery (ORVR) system. ORVR is a vehicle evaporative emission control system that captures fuel vapors during the refueling process. A new fill vent valve has been added to the system to direct the fuel vapors into the charcoal canister. Although the system still operates in a similar manner, the canister, canister close valve and related components have been moved to the rear of the vehicle. Only the canister purge valve remains in the engine compartment. The effect of this change is mostly seen in the HDS graphs when an evaporative emission self check is performed. (Compare HDS graphs 1 and 2 to graphs 3 and 4).

NOTE

Make sure the fuel tank is not completely full when performing the 1998 Elantra/Tiburon evaporative emission self check. If the fuel tank is completely full, the HDS waveform may not be as easy to evaluate (see graph #5).

New for 1998 Accent:

All 1998 Accents have the enhanced evaporative emission system similar to the 1996-1997 Elantra system. Previously, only the 1997 DOHC GT Accents had the enhanced evaporative emission system. The evaporative emission system self check HDS graphs appear very similar to the Elantra Tiburon graphs.

New for 1998 Sonata:

1998 Sonatas have the enhanced evaporative emission system on California Certified vehicles. This system operates differently from the Elantra and Accent engine control systems and the self check occurs under different conditions. Troubleshooting leaks requires the "Pressurize/Clamp/Observe" method described on pages 11-14.

NOTE

When connecting the 1998 Sonata to HDS, select the vehicle as California Specification. When this TSB was published, the Differential Pressure Sensor (DPS) could only be selected when choosing the California Certified vehicle.

QUICK REFERENCE TROUBLESHOOTING:

P0446:

1. Inspect the canister purge valve (CPV) as described in "canister purge valve inspection." Replace valve as necessary.
2. Inspect the "Fresh Air" circuit. Use the "Pressurize/Clamp/Observe" method to isolate a possible blockage by disconnecting hoses at different points, each time farther from the canister.
3. Inspect the canister close valve (CCV) as described in "canister close valve inspection." Replace valve as necessary.

P0441:

1. Inspect the canister purge valve (CPV) for a mechanically "partially open" condition as described in "canister purge valve inspection." Replace valve as necessary.

P0455:

1. Check for a missing/loose gas cap first.
2. Inspect for pinched hoses in the "Purge or Tank" circuits causing a vacuum restriction to DPS.
3. Determine whether the leak is at the front or rear of the car, and use the appropriate schematic to isolate the leak in one circuit at a time by applying hose pinching pliers at different locations until the source of the leak is found. See troubleshooting procedure.

P0442:

1. Determine whether the leak is at the front or rear of the car, and use the appropriate schematic to isolate the leak in one circuit at a time by applying hose pinching pliers at different locations until the source of the leak is found. See troubleshooting procedure.
2. For 1998 Elantra/Tiburon with no apparent leak found, verify that the white fill vent valve plunger moves freely inside its cage. See Fill Vent Valve troubleshooting
3. For 1998 Elantra/Tiburon with no apparent leak found, verify canister close valve seals properly as described in "canister close valve inspection." Replace valve if necessary.
4. For 1998 Sonata, check for a missing gas cap.

DIAGNOSTIC SELF CHECK PROCEDURES:

Connecting The Vehicle To HDS:

To make your HDS screen appear like Graphs 1-5, follow the steps outlined below:

1. Connect HDS to the vehicle, enter "SIMU-TECH", then select "SIGNAL WAVEFORMS".

1. At the signal selection screen, select "ORDER", and then select "BY NAME". Then select "CANISTER CLOSE VALVE", "CANISTER PURGE SOLENOID", and "DIFFERENTIAL PRESSURE SENSOR".

1. Select "OPTIONS", and select "ANALOG RECORD".

1. Select "CTRL" (control), select "MS/DIV", and then select "300 MS/DIV".

1. Select "OK", then select "RUN".

1. Start the vehicle and look at your watch (the self test occurs 16 minutes and 48 seconds after start-up).

1. After start-up, verify that the voltage for the canister close valve and canister purge valve is approximately 13.5 volts, and the DPS reads approximately 1.6 - 2.7 volts depending how recently the purge control solenoid was last activated. The self check will not occur if the DPS is below 1.6 volts. If the DPS is below 1.6 volts, stop here and perform troubleshooting procedure P0446 on page 2 of this TSB.

1. After 15 minutes, begin watching the "CAN CLOS" (Canister Close Valve) signal.

1. As soon as the canister close valve voltage drops to near zero, wait 39 seconds.

1. Touch the screen to stop recording.

1. Select "OPTIONS", then "DATA PLAYBACK".

1. Select "ZOOM", then select "-32". The screen will now look similar to graphs 1-5 in this TSB. You may have to SCROLL the data FORWARD or BACKWARD to get the data onto your screen.

Using The HDS Digital Overlay Feature:

After performing steps 1-12 to capture the self check, the digital overlay feature can be used to determine exact voltages and time frames at any point on the waveform.

1. Select "CONTROL" then "DIGlTAL", and then "OK".

1. Use the track ball to place the cursor on your starting point and click the track ball button.

1. Move the cursor to the left or to the right to analyze the data desired.

Using The Hyundai Scanner To Activate The Self-Check:

For 1997 Elantra, 1997 Tiburon, and 1997 DOHC Accent, scanners with cartridge V1.8 can be used to activate the self check anytime after the vehicle reaches operating temperature. However, the scanner will not activate the self check for 1996 and 1998 vehicles at this time.

1. Set up and run HDS as described earlier in steps 1-5.

1. Make sure the vehicle is at normal operating temperature, there are no DTC codes present (clear any codes before performing the check), and the O2 sensor is in Close Loop.

1. If all conditions are met, start the Evap Check and the scan-tool will display "Now Trying to Trigger Evap Test". A few seconds later "Waiting For Evap Test To End" is displayed.

1. Approximately 30 seconds later, the message "Evap Test Complete" will be displayed. Wait about 10-15 seconds to stop the HDS recording (continue with steps 10-12).

GRAPH #1: EXAMPLE OF 98 MY ELANTRA/TIBURON WITH FULL FUEL TANK--GOOD PLOT

GRAPH #2: EXAMPLE OF 98 MY ELANTRA/TIBURON WITH EMPTY FUEL TANK--GOOD PLOT
EXAMPLE OF 97 DOHC/98 MY ACCENT WITH FULL FUEL TANK--GOOD PLOT

GRAPH #3: EXAMPLE OF 96/97 MY ELANTRA/TIBURON WITH FULL FUEL TANK--GOOD PLOT
EXAMPLE OF 97 DOHC/98 MY ACCENT WITH EMPTY FUEL TANK--GOOD PLOT

GRAPH #4: EXAMPLE OF 96/97 MY ELANTRA/TIBURON WITH EMPTY FUEL TANK--GOOD PLOT

GRAPH #5: EXAMPLE OF 98 MY ELANTRA/TIBURON WITH TOO FULL FUEL TANK

This is an example of a waveform where the fuel tank is too full of fuel. The tank must be drained a few gallons to assure consistent results that can easily be evaluated. This condition can also be caused if the fill vent valve plunger is stuck. See the troubleshooting section for the Fill Vent Valve.

ENHANCED EVAPORATIVE EMISSION TROUBLESHOOTING

Perform the following to inspect the system for leaks:

NOTE

#1: The procedure described below assumes that all electrical connections are in good condition.

NOTE

#2: A "test" hose should be made from an 18 inch (457.2 mm) length of 3/8 inch (9.53 mm) fuel hose to perform most of the diagnostic procedures.

NOTE

#3: Two pairs of hose pinching pliers (Snap-On part# BLC2 or equivalent) will be needed to help troubleshoot the system.

1. Referring to the appropriate schematic, connect and clamp the "test hose" to the following hose in the system:1998 Sonata:The hose is located between the canister and the two way valve (Photo 1 - Left, rear of vehicle).

PHOTO 1: 1998 SONATA

1998 Elantra/Tiburon:The hose is located between the canister and the canister close valve (Photo 2 - Left, rear of vehicle).

PHOTO 2: 1998 ELANTRA/TIBURON

NOTE

For 1998 Elantra/Tiburon, the fuel tank must not be completely full to perform the following procedure. If the fuel tank is completely full, the waveform may not be as easy to evaluate.

1996/97 Elantra/Tiburon; 1997 DOHC/1998 Accent:The hose is located between the canister air filter and the canister close valve (Photo 3 - Left, front, inner fender of vehicle).

PHOTO 3: 1996/97 ELANTRA/TIBURON 1997 DOHC/1998 ACCENT

1. Connect HDS to the vehicle, enter "SIMU-TECH", then select "SIGNAL WAVEFORMS".
2. At the signal selection screen, select "ORDER", "BY NAME" and then "DIFFERENTIAL PRESSURE SENSOR".
3. Select "OPTIONS" and select "DIGITAL RECORD".
4. Select "OK" and then select "RUN".
5. Set the ignition switch to the "ON" position.
6. While watching the DPS signal on HDS, GENTLY begin to blow into the fuel hose with approximately 1.0 psi (the DPS voltage should begin to rise). Continue to gently blow into the hose until the DPS voltage is approximately 4.0 volts. Do not over pressurize since the sensor cannot read over 4.7 volts.

1. When the DPS reads approximately 4.0 volts, immediately clamp the "test" hose with hose pinching pliers (see Photo 4).

PHOTO 4: 1998 SONATA

1. In a good system, the voltage will remain steady or even rise slightly if the canister is at the rear of the car (the value must remain constant: ±0.05 volts over 10 seconds). If the voltage drops, go to step E. If the voltage remains steady, go to step C.
2. By removing the hose pinching pliers, the system should return to atmospheric pressure (2.5 ± 0.2 volts) within 25 seconds. If the voltage takes longer than 25 seconds to return to 2.5 ± 0.2 volts, go to step J.
3. If it takes longer than 25 seconds, check for restricted vapor hoses or internal blockages in the "to tank" circuit. Correct any conditions found. Repeat step 2.
4. If the DPS voltage decreases after clamping, a leak is present in one of the circuits or at the canister. Isolate the leak into either the Purge, Tank or Fresh Air circuits. Use the procedure outlined below.
5. Pressurize and clamp as described in steps 2 and 3a, and connect a second set of hose pinching pliers at the "to tank" vapor hose on the canister. If the voltage drops, go to step G. If the voltage remains steady, go to step l.
6. Pressurize and clamp as described in steps 2 and 3a, and connect a second set of hose pinching pliers at the "purge" vapor hose on the canister. If the voltage drops, go to step H. If the voltage remains steady, go to step I.
7. Inspect the canister for a small leak by clamping both the "Purge" and "to tank" vapor hoses, and supplying a low pressure source (approximately 1 psi) into the fresh air nipple, while spraying the canister with soapy water. If a leak is found, replace the canister. If no leak is found, repeat procedure starting at steps 2 and 3a.
8. If the DPS voltage remains steady after the second set of hose pinching pliers are clamped, then the leak is on the other side of the "clamped" circuit. Pressurize and clamp as described in steps 2 and 3a, each time moving the second set of hose pinching pliers farther away from the canister, but in the same circuit until the leak is found. The "test hose" connection may have to be moved to different areas when checking the "to tank" circuit. Use the schematic to try to keep the DPS in the system when pressurizing and observing for leaks.
9. If no apparent leak is found, thoroughly check the "fresh air" circuit and the canister close valve as described in "canister close valve inspection".

CANISTER CLOSE VALVE INSPECTION: