Please Translate those Codes

  • 8 POSTS

Ok I just bought OBD II reader ( I don't know where to get vag-com) & got those 7 codes

P0725 (twice)
P1850 (twice)
P1780 (twice)

now the book came with this OBD have desc. For 140 & 725 which is

P0725: Engine Speed Input Circuit
P0140: O2 Circuit No Activity Detected (Bank1, Sensor 2)

i don't what that means & plus have no clue about others two codes.

please advice

Do you
have the same problem?
Tuesday, October 23rd, 2007 AT 7:52 AM

1 Reply

  • 45 POSTS

Heres how the codes are broken down:

letter - digit - digit - digit - digit

The letter could be 1 of 4 letters, they are as follows:
B = Body
C = Chassis
P = Powertrain
U = Network

The first digit represents type of code, be it Generic or Manufacturer Specific, as follows:
0 = Generic
1 = Manuf. Specific
2 = Generic
3 = Includes both Generic and Manuf. Specific Codes

The second digit identifies the the specific system or subsystem where the malfunction occurs, as follows:
1 = Fuel and Air Metering
2 = Fuel and Air Metering (injector circut malfunction only)
3 = Ignition System or Misfire
4 = Auxillary Emission Control System
5 = Vehicle Speed Controle and idle control system
6 = Computer Output Circuts
7 = Transmission
8 = Transmission

The third and fourth digits represents the section of the system that is malfunctioning. This varies from malfunction to malfunction, but as an example:
01 = cylinder 1
02 = cylinder 2
03 = cylinder 3
* This will differ per system/subsystem that is malfunctioning, so do not diagnose any issues using the top 3 examples*

So, now lets break down your remaining 2 codes:
p1850 = powertrain VW Specific Transmission malfunction

p1780 = Powertrain VW Specific Transmission Malfunction


Now then, explanation of codes:
p0725 = Engine Speed Input Circut:
Engine Speed Sensor circut malfunctioning.
Solution: the eSS is located right above the oil filter, under the plastic cover on your intake manifold. Its a 3 plug plastic fitting with a metal clamp holding it in place. Squeeze the sides of the clamp and pull to remove the electrical connector to the ESS. Using a Digital Multimeter or an Ohmmeter, measure the resistance of the sensor across terminals 2 and 3. (terminal 1 is the flattened side of the plug, terminal 3 is the rounded side of the plug.) The resistance should be 480 to 1000 ohms on 2.0L motor or 780 to 1000 ohms on a 1.8L motor. Check for continuity between terminals 1 and 2, then 1 and 3. No continuity (Infinity) should be indicated. If the ESS fails either of the tests, replace the sensor. If the sensor passes the tests, backprobe the electrical connector for the ESS. Look for any breaks, melts, or tears in the wiring, and repair as needed.

P0140 = 02 sensor dead bank 1 sensor 2:
There are 2 oxygen sensors on your vehicle. They are located at the Catalytic Converter. Follow the exhaust pipe from the motor to the rear of the car. The Catalytic Converter comes before the muffler. The sensor on the motor side of the converter is sensor 1 or pre-converter. The sensor on the rear-end side of the converter is sensor 2 or post-converter. In your case, the o2 sensor on the rear-end side of the converter has malfunctioned, and should be replaced. They only cost roughly 15.00 from your local auto-parts store. Removal and Installation is fairly self explanitory.
*Remember, anytime you replace a sensor or any electrical component that has malfunctioned you must use a code-scan tool to clear the ECM before starting your vehicle! Failure to do so could severely impact the driveability of your vehicle!*
As for the remaining two codes:
they are vehicle/manufacturer specific, google the codes with your make/model. You will come across a detailed table of every code for your vehicle eventually. More likely than not, being a man. specific tranny issue, you are going to need to take your car to a certified transmission specialist or to the dealership to be repaired. If you didnt know already, VW claims to have created the perfect transmission, that should never need to have the fluid changed, or serviced, ever... so your VW's tranny is a "sealed unit", meaning you cannot easily change fluid, add fluid, check fluid, or anything. On top of that, the only way to check or change the fluid, VIA the Tranny fluid filler and the fluid check dipstick are both located on the BOTTOM of your transmission. So I would recommend that you find a tech that specializes in BMW, AUDI, VW, VOLVO repairs, those would be the best place to start after you figure out what the problem is. If you are a DIY type of guy, I recommend that you invest the 20.00 dollars in the haynes repair manual for your vehicle. Follow directions thoroughly and never skip over any steps! You can easily find yourself buying a new tranny real quick, among other things, if you are not 100% sure of yourself and careful. I hope this explains a bit, and I hope it helps!

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Sunday, November 18th, 2007 AT 12:06 AM

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