Accelerator Pedal Position Sensor Mismatch

[Mikka]

My 04 CL9 has recently been doing strange things while cruising. The best way to describe it is that the power drops off then surges back on very quickly, as if taking your foot quickly off the pedal then back on to where you were. Its done this to me on a few occasions, but my partner drives it more often and notices it happening quite a bit.

A few weeks ago on a highway trip, it did this a few times before the power dropping right off and the engine check lights all coming on. Once safely pulled over, an engine restart fixed it (temporarily) and resumed the journey. This happened a few more times that day.

We took it in for its 90k service a few days later (it was at 89k anyway) to Southside Honda and asked them to fix it, and they said that the ECU reported an Accelerator Pedal Position Sensor A-B correlation error, that they'd cleared the error off the ECU and couldn't replicate it on the day. If it happened again, they could order us a whole new APP sensor assembly and wiring harness from Japan (2 weeks shipping) and install it for us (quoted around $500 incl labour).

I managed to track down a service manual for an 04 TSX (the US version of the car) and the diagnostics for an APP sensor mismatch are basically to clear the ECU, start the engine and depress the throttle. If the ECU doesn't report an error then its an intermittent fault and there are no further diagnostic steps in the service manual.

Since then, the car has continued to do the 'lose power then surge back on' thing a few times, especially on light throttle application, which to me seems to imply one of the two APP sensors is getting stuck at a wrong reading when lightly depressed.

Does anyone know any good Honda mechanics around Brisbane who'd be able to diagnose this properly? or am I better off just buying a whole new sensor assembly and forking out the $500?

Thanks,
Mikka.

(My right elbow is broken at the moment, so any DIY ideas are out at the moment)

[chrome]

Southside Honda basically read the OBD2 codes stored on the ECU, and learn it was the accelerator pedal position correlation error. It happens when both potentiometers are not in agreement with each other, and the ECU goes into a limp mode which explains your surging and loss of power. You have very little options but to have the whole assembly replaced, there's no individual components to swap out.

[Lochstar_69]

I just cured the exact problem you are having, my local mechanic sourced the part from a wrecker and i was back on the road after 5 days. i was told the parts for euros are scarce and i needed the car back asap, so i sacrificed the 3 week wait from japan for the new sensor box and put in the second hand part, its fixed and driving like a dream again :D.

the second hand part costed me 430 including labour. Part separate was $200.

[Lochstar_69]

p.s hope this is not going to become a problem among the earlier euro's

[Mikka]

I just cured the exact problem you are having, my local mechanic sourced the part from a wrecker and i was back on the road after 5 days. i was told the parts for euros are scarce and i needed the car back asap, so i sacrificed the 3 week wait from japan for the new sensor box and put in the second hand part, its fixed and driving like a dream again :D.

the second hand part costed me 430 including labour. Part separate was $200.

Sounds like there's not much to be saved by sourcing the part independently... so I may as well just get them to order it all from Japan and take the car in after Xmas.

The guy at Southside Honda said he's seen this about 5 times since the Euro was released, so its not a common fault, but not unheard of.

[tony1234]

Sounds like there's not much to be saved by sourcing the part independently... so I may as well just get them to order it all from Japan and take the car in after Xmas.

The guy at Southside Honda said he's seen this about 5 times since the Euro was released, so its not a common fault, but not unheard of.
I had the same problem nearly 3 weeks ago.Fault code P21138 APP sensor A-B faulty.They reset the ECU and all is good now.My car is 06 model,just out of warranty but HA are supplying the part($298.00)at no charge and i pay labour($100.00).Approx.2 week wait from Japan for part.Try and get the part for trade price (less 10%)

[najhans]

I had the same problem nearly 3 weeks ago.Fault code P21138 APP sensor A-B faulty.They reset the ECU and all is good now.My car is 06 model,just out of warranty but HA are supplying the part($298.00)at no charge and i pay labour($100.00).Approx.2 week wait from Japan for part.Try and get the part for trade price (less 10%)

My euro CL9 having the same problem recently. As I in Malaysia right now, Honda Malaysia cannot provide me the part. I got no choice other than get it from OZ (I bought this car when I studied in Canberra). Interestingly, my fault code is P2138 but it still a APP sensor fault. Can somebody explain what is the different. I really want to find out the part number so that I can request my friend to get it from HA. Can somebody help me to get the part number?

[aaronng]

Interestingly, my fault code is P2138 but it still a APP sensor fault. Can somebody explain what is the different.
The difference is he typed the number "1" twice by mistake. The code is P2138, the same as what you have.

[najhans]

The difference is he typed the number "1" twice by mistake. The code is P2138, the same as what you have.

Many thanks indeed mate. btw, do you know how i can get the part number as reference?

[aaronng]

Many thanks indeed mate. btw, do you know how i can get the part number as reference?

From this thread: http://www.ozhonda.com/forum/showthread.php?128057-Accelerator-Position-Switch&highlight=accelerator+pedal+sensor

The part number should be 37971-RBB-003

[tony1234]

The difference is he typed the number "1" twice by mistake. The code is P2138, the same as what you have.
Hmmmm,just checked the paperwork i got when i had the APP sensor replaced and it states fault code P21138!Maybe it was a typo from the service guy.:confused:

[aaronng]

Hmmmm,just checked the paperwork i got when i had the APP sensor replaced and it states fault code P21138!Maybe it was a typo from the service guy.:confused:

Yes, it is a typo from the service guy. Honda P codes have only 4 numbers after it, not 5.

[blk_shadow]

reviving this thread. I recently got this issue, where you step on the throttle and it takes a long time for the car to accelerate. (my euro has throttle cable therefore i dont think it has APP sensor)

no CEL, just happens intermittently.

I thought its a fuel pump issue, anyone knows?

cheers

[SPQR]

The APP is located at the other end of the cable. But you don't say what car you have.

I have a 2004 CL9 with the same problem described by the original thread. The problem was the APP on my car. My local dealer replaced it at great cost and the problem went away. The part number was 37971-RBB-003. The part is much cheaper in the USA.

[blk_shadow]

Thx for the reply spqr, my car is a 2004 accord euro R with throttle cable.

Do you think it has APP still?

[SPQR]

Is it a CL7 from UK? A drive-by-wire throttle was a feature of the CL series euro Accord so yours should have a cable that connects the accelerator pedal to APP in the engine bay.

Have a look at what the APP looks like at:

http://parts.sonsacura.com/showAssembly.aspx?ukey_assembly=270594&ukey_make=987&ukey_model=13649&modelYear=2004&ukey_category=19654&ukey_driveLine=6276&ukey_trimLevel=12435

See if it matches the 'thing' at the other end of the cable...

[blk_shadow]

Mine is CL7 accord euro R from Japan, so its running K20A throttle cable.

I'll check it out tonight.

Cheers