andyz

2000 Accord 90k miles no mods, F23A1, MAXA

Pulled codes and found a likely ancient P1739, Third Clutch Pressure Switch.

OBD II scanner software reports there is Freeze Frame data to go with...

I use a serial port software to get any PID I want. like this.

ATI
"ELM 327"
010C
"BUS INIT...DONE, 01 0C 0C 78"

When I ask for Mode 2 PID, 020C, result is No Data.

What possible PIDs is Honda recording in freeze frame for a P1739?

MAD_MIKE

I'm guessing it is just merely saving the point in memory for future reference.
What exactly it is saving may be just the pressure 3rd clutches pressure sensor registered value at the time that caused the code to be set.
But the PID may not be fully supported on the ECM, or with your scanner, and may require the appropriate Honda scanner to register/calculate its true value.

Is the 3rd clutch switch a variable resistor, or simply an switch? If it is a switch then there probably is no data other than the switch was turned on/off and the code was set.

DCFIVER

Ayntime a DTC is set,it is mandatory for the PCM to store the data parameters as they are, at the time of the fault. These parameters are simply the basic OBD 2 generic data PIDS. They are unlikely to be of any use for the P1739....

andyz

Allright, so the future reference, I had it backwards.
The commands to retrieve freeze frame are formatted thusly:

Mode, PID, Frame#
020c00

Not

Mode, Frame, PID

Frame number is always zero I think.

Now, What would cause my Third Clutch Pressure Switch to have some detectable problem at:

2393 RPM
70 KM/H
29 % Throttle Position
84 deg Celcius (slightly under full operating temp)
STFT and LTFT similar to idle conditions
IAT 85 deg Celcius

What shall I do? Clear the code and the freeze frame now and see if it comes back?

MAD_MIKE

Check that the fluid level is full.
Check that the sensor is not loose/leaking/broken connection/wire.

IIRC on 98-02 ATs that sensor is known to fail.

andyz

Fluid level is perfect. Overall inspection gives absolutely no indication of broken, loose, leaking sensor connections, gaskets.

Cleared code. Drive a few miles , highway, and local roads, code doesn't come back.

What's up with that? Is that pressure sensor just flaky? Is it failing slowly? OR, it there some other, hydraulic circuit, clogged filter, etc, problem, that is known to show up as Third CLutch PRessure sensor failure?

MAD_MIKE

If the code happened when you did not own the car, PO may have done something. May have driven it low on fluid, may have had an intermittent connection, may just be the sensor is flaky/failing/voodoo.

Maintain the transmission and it should be fine, until it isn't.

andyz

http://www.hondapartsnow.com/diagram...oid-456565.png

#12 and #13

Which one is 2nd, which one is 3rd?



12 28600-P6H-003 SWITCH ASSY., OIL PRESSURE JPN, USA 1 $77.08 $55.50
13 28600-P7Z-003 SWITCH ASSY., OIL PRESSURE (TEXAS INSTRUMENTS) JPN, USA 1 $72.02 $51.85

What's the PSI on these?


http://www.napaonline.com/Catalog/Ca...692_0353956308

IMPORTANT INFO: 33 PSI Black Connector

http://www.napaonline.com/Catalog/Ca...691_0353956310

IMPORTANT INFO: 38 PSI Green Connector

So, what is what here?