Disclaimer: The following is provided as a GUIDE ONLY, and neither myself nor Ozhonda take any responsibility for the outcomes of someone else doing the following. You follow these steps at your own risk!
No part of this DIY is to be reproduced with out acknowledgment of the site and author it came from, ie me and ozhonda.com. Do not rip parts off and claim them as your own.
VTP Switch "VTEC Pressure Switch". The VTP switch is commonly located on the side of the head next to the distributor. OBDII cars may not have a VTP Switch. When the VTP Switch is in its normal state its normally closed. As the VTEC solenoid engages and oil pressure is detected by the VTP it goes open circuit.
Aim:
Diagnose code 22.
Required:
Basic Testing
- Digital Multi Meter
- paper clip
Advanced Test
- air compressor
- air blower
- shifter spanner
Symptoms
A faulty VTP Switch will trigger code 22. The MIL will light up and VTEC will not engage. The engine will rev happily to redline on low speed cam. If you are using a OBDI ECU on your OBDII car and are getting code 22, you will have to add a VTEC Pressure Switch, or disable it in the ROM. ( or add a relay to trick the ECU ).
Basic Test
- Perform a Visual inspection and make sure the VTP is Connected or is even there.
VTP Switch Pin out Picture
wire side of connector
**** Continuity Test ****
STEP 1
make sure the Ignition is off and unplug the VTP Connector.
Continuity test between VTP Pin 1 and Pin 2, Connect your Red multi meter lead on the VTP Pin 1, Connect the Black multi meter lead on the VTP Pin 2. Make sure you connect the multi meter leads to the actual VTP not the connector for this test.
Make sure your two multi meter leads are not touching each other, only the VTP pin. Your multi meter should beep and read short or 000.0ohms.
If you do not get continuity replace the VTP
STEP 2
make sure the Ignition is off and unplug the VTP Connector and the ECU Connectors for this test
Continuity test between VTP Pin 1 and ECU, Connect your Red multi meter lead on the VTP Pin 1, Back probe* the Black multi meter lead on the ECU Pin bellow that suits your car.
OBDO = B5
OBDI = C6
OBDIIa = C15
OBDIIb = C10
Your multi meter should beep and read short or 000.0ohms. Place the black multi meter lead on a good ground source. You should not get beeping, this is testing for short to ground.
STEP 3
make sure the Ignition is off and unplug the VTP Connector for this test. ECU connectors must be Connected.
Continuity test between VTP Pin 2 and Ground, Connect your Red multi meter lead on the VTP Pin 2, Place the black multi meter lead to a known good ground.
Your multimeter should beep and read short or 000.0ohms.
**** Advanced Continuity test ****
STEP 1
note: for this test you must ware saftey glasses
Remove the VTP from the car by unscrewing it from the VTEC valve assembly. place it on the bench and connect the multi meter leads to it as mentioned in step 1 of the above test.
Apply air pressure with an air blower connected to an air compressor to the VTP in its end where the oil enters.
As you apply air pressure the multi meter should read open circuit. When you are not applying air pressure the multi meter should read short.
* Notes
KOEO = Key On Engine Off
KOER = Key On Engine Running
Back probe the sensor, use a paperclip and push it into the connector then touch/clip your multi meter lead to the paper clip
Disclaimer: The following is provided as a GUIDE ONLY, and neither myself nor Ozhonda take any responsibility for the outcomes of someone else doing the following. You follow these steps at your own risk!
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