Tech724

Hey,

New to this forum just wanted to introduce myself (Karl) the reason I joined is because my gf drives a 2002 Civic which has a MIL or CEL on with a P1259 DTC that comes and goes. Im a Tech of about 10 years worked in several independent shops for about 7 of those years and worked for Ford for the Last 3 years. No w im currently a lead tech at a fleet shop (Penske Truck Rentals) I have done mostly Diesel work for the last 2+ yrs had a few questions about the honda common problems with the vtec systems and was tryin to see if i could get some support. Im a long time racer (motocross, Drag, Street, & Stock cars) I have driven mostly Fords but Raced a GST Eclipse for a couple years on the street/strip. I have a vast knowledge of mechanical/electrical Diag. just not really familiar with the vtec systems and im not about gettin *** raped by a mechanic when i own 50k+ in tools and diag equipment lol

Thanks,
Karl

MindBomber

You need to change the VTEC fluid.

MindBomber

Just kidding, here's the service manual guide..

Step 1) Reset the ECM/PCM

to do this you need to pull a fuse under the hood. Its the No. 6 ECU 15A

pull this fuse for 15 seconds and then reinsert it

Step 2) Check the oil level, and refill is necessary

Step 3) Start the engine, put the car in park if you have an auto, neutral if you have a 5-speed. Hold the RPM's at 3000 RPM until the radiator fan comes on, don't turn off the car just yet.

Step 4) Time to go for a drive, accerlate in first gear to an engine speed over 4000 rpm. Hold the engine speed for at least 2 seconds. If DTC P1259 is not repeated during the first test drive the try this test 2 more times.

Is DTC P1259 indicated?

YES - Go to Step 5
NO - Intermittent failure, system is OK at this time, Check for poor connections or loose terminals at the VTEC solenoid valve, at the VTEC pressure switch, and the ECM/PCM

Step 5) Turn the ignition off

Step 6) Remove the resonator, basically your stock intake is 3 parts, the part right above the throttle body, we'll call this piece A. The middle part that runs from piece A and that extension pipe over by the battery. This middle piece is the piece you want to remove.

Note, im guessing that if you have an aftermarket intake your going to need to put your stock intake back on.

Step 7) Disconnect the VTEC oil pressure switch 2p connector

Step 8) Check for continuity between the VTEC oil pressure switch p2 connector terminals No 1 and No 2

Is there continunity?

YES - Go to Step 9
NO - Replace the VTEC oil pressure switch

Step 9) Turn the ignition switch to ON (II)

Step 10) Measure the voltage between VTEC oil pressure seitch 2p connector 1 and body ground.

Is there battary voltage

YES - Go to Step 15
NO - Got to Step 11

Step 11) Measure the voltage between the ECM/PCM terminal B9 and body ground

Is there battery voltage?

YES - Repair the open wire between the VTEC oil pressure switch and the ECM/PCM (B9)
NO - Go to Step 12

Step 12) Turn the ignition switch off (II)

Step 13) Disconnect the ECM/PCM connector B (24P)

Step 14) Check the continuity between ECM/PCM connector terminal B9 and body ground.

Is there continuity?

YES - Repair the short in the wire between the VTEC oil pressure switch and the ECM/PCM (B9)
NO - Update the ECM/PCM software if it does not have the latest software, or substitute a known-good ECM/PCM, the recheck. If the symptom/indication goes away with a known-good ECM/PCM, then replace the orginal ECM/PCM.

Step 15) Measure the voltage between VTEC oil pressure switch 2p connector terminals 1 and 2

Is there battery voltage?

YES - Go to Step 16
NO - Repair open wire between the VTEC oil pressure switch and G101.

Step 16) Turn the ignition switch off (II)

Step 17) Disconnect the VTEC soleniod valve 1p connector

Step 18) Check the resistance between VTEC soleniod valve 1p connector and body ground

Is there 14-30 ohms?

YES - Go to Step 19
NO - Replace VTEC solenoid valve

Step 19) Remove the VTEC oil pressure switch (A), and install the special tools as shown, then reinstall the VTEC oil pressure switch

Step 20) Reconnect the VTEC solenoid valve 1p connector and the VTEC oil pressure switch 2p

Step 21) Connect a tachometer

Step 22) Start the engine, put the car in park if you have an auto, neutral if you have a 5-speed. Hold the RPM's at 3000 RPM until the radiator fan comes on, don't turn off the car

Step 23) Check the oil pressure at engine speeds of 1,000, 2,000, and 4,000 rpm. Keep the measuring time as short as possible (less than 1 minute) because the engine is running with no load

[i]Is the oil pressure below 49 kPa (.0 kgf/cm^2, 7 psi)?

YES - Go to Step 24
NO - Inspect the VTEC solenoid valve

Step 24) Turn the ignition switch off

Step 25) Disconnect the VTEC solenoid valve 1p connector

Step 26) Attach the battery positive terminal to the VTEC solenoid valve terminal

Step 27) Start the engine and check the oil pressure at 3,000 rpm

Is the oil pressure above 390 kPa(4.0 kgf/cm^2, 57 psi)

YES - Go to Step 28
NO - Inspect the VTEC soleniod valve

Step 28) With the battery positive terminal still connected to the VTEC solenoid valve, measure voltage between ECM/PCM connector terminal B9 and body ground.

Is there battery voltage above 4,000 rpm?

YES - Go to Step 29
NO - Replace the VTEC oil pressure switch

Step 29) Turn the ignition switch off

Step 30) Disconnect the battery positive terminal from the VTEC solenoid valve terminal

Step 31) Disconnect the ECM/PCM connector B (24P)

Step 32) Check the continuity between the ECM/PCM connector terminal B15 and body ground.

Is there continuity?

YES - Repair the short in the wire between the VTEC solenoid valve and the ECM/PCM(B15)
NO - Go to step 33

Step 33) Connect VTEC solenoid valve 1p connector terminal No. 1 to a body ground with a jumper wire

Step 34) Check for continuity between ECM/PCM connector terminal B15 and body ground

Is the continuity?

YES - Update the ECM/PCM software if it does not have the latest software, or substitute a known-good ECM/PCM, the recheck. If the symptom/indication goes away with a known-good ECM/PCM, then replace the orginal ECM/PCM.
NO - Repair open in the wire between the VTEC solenoid valve and the ECM/PCM (B15)