gas pedal wont flash my motronic 1 3 codes

[Kozworth]

I read up and watched videos of putting the key on the on position and hitting the pedal down 5 times all the way

I tried even with the tb as opposed to the gas pedal and tried different speeds no luck

I have an 88 325is so it should have motronic 1 3

Sorry my period button doesn't work on my phone please let me know what im doing wrong I get a cel when idling and figure it could help me solve my idle issue

[Sagaris]

Check your idle and full throttle switches with a continuity tester on the 3 throttle position swtich pins under the throttle body. One pin is ground, the other is for full throttle, the other is for idle. This is what signals the DME to switch between idle fuel/timing maps, part-throttle maps, and full throttle maps. A CEL at idle and poor idle can be caused by the DME not receiving the signal from the idle switch that the throttle is closed. It then tries to use part-throttle fuel and timing when the car is at idle, which is not ideal. You should have continuity at idle for the idle switch when the throttle is closed, and continuity at or near full throttle for the full throttle switch. These switches being bad/out of adjustment would cause both of your issues. There is a small amount of adjustability in the mounting screws for the TPS which will get you working right again if the switch is just not making contact.

[Kozworth]

Wow I hope that would be it

Noob question but im basically doing a voltage drop on these sensors or disconnecting the battery and testing for ohms to see continuity

Sorry its been well overdue since I broke out my dmm

[Sagaris]

Wow I hope that would be it

Noob question but im basically doing a voltage drop on these sensors or disconnecting the battery and testing for ohms to see continuity

Sorry its been well overdue since I broke out my dmm

I know that in the world of electrical engineering using a continuity tester on some things is frowned upon since it pumps a small amount of current through whatever circuit you are testing but I am a mechanical engineer and use a continuity tester that beeps when a connection is present.

If all you have is an ohm-meter then that will work as well. You want to see resistance changes as the switch engages/disengages

[Kozworth]

Alright sounds like my project for tomorrow

[Sagaris]

If you are good at using chopsticks then you can check the TPS with the test leads in one hand without removing anything but the electrical connector for the TPS but you may end up needing to remove the intake boot to get a good confident contact on the correct pins with the test leads. You WILL need to remove the throttle body if the switch needs replacing or adjusting, Not a huge deal.

[Kozworth]

Heres the update.

I broke out my ohmmeter, removed the intake boot and removed the 3 pin harness under the TB. I tested with the ground lead in the middle, and red lead on the right at idle. At first I kept getting no readings, but adventually got an ohm reading that way, and an ohm reading with the ground in the middle and the positive lead on the left side with the car simulating WOT.

However, When i tried the harness I would not get anything. I looked in the bentley, and i could not find the tps pins described at all. I think i tested it right but could be wrong.

I happened to actually forget to plug this harness back in, and I was getting a solid 2k rpm idle. After looking for massive intake leaks, and retracking my steps I realized I left this unplugged, and then Now it idles back to how it was before (low 550/600rpm with a loopy idle noise).

I tried the gas pedal trick to trip the codes, and still nothing, yet when I go idle or WOT i get continuity, and if the harness was bad I would assume I wouldnt know a difference when I plugged in the connector to the TPS.

[Sagaris]

Not saying this is your issue, but I have had a bad TPS which would work 1 out of every 7 or 8 tries so I was confused when I had continuity then all the sudden didnt. Testing the TPS pins is the correct way to do it. The harness that goes to the ECU wont tell you anything about the condition of the switch.

[Kozworth]

I figured if I did have continuity I would make sure the circuit to the cpu wasn't open

It probably isn't since I did notice a change whem it was replugged in

Is there a diagram of which lead is wot or idle

[jlevie]

What DME is in the car? For the stomp test to work it must be a 173 or later.

[Kozworth]

Not totally sure I just read anything motronic 1 3 which is 88 and up would be a stomp test

How could I check the dme just by looking at the serial on it

And if it isn't a 173 is there anotherway to check codes

[jlevie]

There will be a label on the DME with a Bosch part number. The last three are the numbers of interest.

FYI: An 88 325 could have a 153. A 153 means using a code reader to get the fault codes.

But you may not even need to get the codes. What problems does the car have?

[Kozworth]

II have a thread devoted to my idle issue and gas mileage

I get a cel when warm and idling usually in the drive thru and things like that and figured it might give me a clue as to what's wrong

Isn't there a way to jump the codes with a paperclip

[smooth]

Isn't there a way to jump the codes with a paperclip

No, what you're probably thinking about is there is a way to reset the service indicator lights on your gauge cluster with a paperclip.

[Kozworth]

OOk so I would basically have to get an obd1 reader I hear ya