# What's the deal with the P1237 Fuel injector cylinder 1: open circuit



## kamikaze2dope (Apr 26, 2003)

I have those 3 codes:
P1237 Fuel injector cylinder 1: open circuit
P0300
P0301
I know about the p0300 codes and did a coil pack swap without any success.
I am about to change the plugs but what's the deal with the P1237?
I double checked the wires near the injector #1 and cant seem to find out.
THX


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## green02turbo (May 13, 2008)

*Re: What's the deal with the P1237 Fuel injector cylinder 1: open circuit (kamikaze2dope)*

Put an OHM meter on your #1 fuel injector. IF its between 12-18 ohms you should be ok, if its infinite or way high, you have an open injector. If your injector is good, check with a 12V test light and make sure it pulses when in place of the injector. I it doesnt (dim, is ok) you have a wiring or ecm issue.


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## kamikaze2dope (Apr 26, 2003)

*Re: What's the deal with the P1237 Fuel injector cylinder 1: open circuit (green02turbo)*

ha man i dont have ohm meter...
My problem persist even after a plug change and i double checked every injector wires...
It gets on my nerves.








Any other way i could test or diagnose the problem?


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## kamikaze2dope (Apr 26, 2003)

*Re: What's the deal with the P1237 Fuel injector cylinder 1: open circuit (kamikaze2dope)*

It sucks looks that i may have to buy 1 ohm meter after reading this:
http://forums.vwvortex.com/zerothread?id=2727771
My car is getting on my nerves


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## kamikaze2dope (Apr 26, 2003)

*Re: What's the deal with the P1237 Fuel injector cylinder 1: open circuit (kamikaze2dope)*

Is by any chance someone got this code once and could pinpoint somewhere to look for.
Injector wire plugged or unplugged i get the same code and engine misfiring #1.
I checked all my fuses.
I checked all wires and even removed my air box to check underneat.
Changed my plugs.
Swapped coils.
Lately an APR TIP and downpipe was added to my car.
I dont have an ohm meter and when i did go to the vw dealer the car was running fine so they werent able to track it.
The problem is intermitent and mostly when the engine is not to temp.


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## kamikaze2dope (Apr 26, 2003)

*Re: What's the deal with the P1237 Fuel injector cylinder 1: open circuit (kamikaze2dope)*

Bump for a guru to shim in!
P1237 prevents me to ride this week-end...


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## kamikaze2dope (Apr 26, 2003)

*Re: What's the deal with the P1237 Fuel injector cylinder 1: open circuit (kamikaze2dope)*

Can you guys confirm that if it would be a relay or something related to the fuel pump i would have the 4 codes N30 TO N33 INSTEAD OF JUST THE N30?


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## green02turbo (May 13, 2008)

*Re: What's the deal with the P1237 Fuel injector cylinder 1: open circuit (kamikaze2dope)*

The P1237 is saying it all. Your injector is open circuit on cyl#1. Pretty cut and dried. You can try swapping injectors to another cylinder and see if the missfire and code follow. That will tell you if you indeed have a open (At times) injector. Find someone with a meter that will help you. Your P0301 is caused by your P1237. Fix it and the P0301 will go away also most likley.


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## kamikaze2dope (Apr 26, 2003)

*Re: What's the deal with the P1237 Fuel injector cylinder 1: open circuit (green02turbo)*

I did the injector swap and again it's the 1237 cyl. #1...
I will go drop the car at the dealer cuz im exhausted and cant seem to find the bad wire.

_Quote, originally posted by *green02turbo* »_The P1237 is saying it all. Your injector is open circuit on cyl#1. Pretty cut and dried. You can try swapping injectors to another cylinder and see if the missfire and code follow. That will tell you if you indeed have a open (At times) injector. Find someone with a meter that will help you. Your P0301 is caused by your P1237. Fix it and the P0301 will go away also most likley.


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## kamikaze2dope (Apr 26, 2003)

*Re: What's the deal with the P1237 Fuel injector cylinder 1: open circuit (kamikaze2dope)*

If i have a gas cut off switch custom maded using one of the engine fuse wire... Could this cause my fault code.
Like theres is a bad connection and it could trigger only one cylinder fault instead of the 4 ?


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## gdoggmoney (Feb 21, 2004)

Check continuity and resistance from the injector harness to the ECU.
The ECU gives switched 12v+ to the injectors when the key is on iirc. 
It grounds them for a certain amount of time to fire them. 
Start tracing the wiring back to the ECU. 
If I am wrong correct me, it's been a while since the MS build.


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## kamikaze2dope (Apr 26, 2003)

*Re: (gdoggmoney)*

?

_Quote, originally posted by *gdoggmoney* »_MS build.


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## gdoggmoney (Feb 21, 2004)

*Re: (kamikaze2dope)*


_Quote, originally posted by *kamikaze2dope* »_?


megasquirt.


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## matterthemadhatter (Feb 23, 2010)

how did you resolve this issue? have same code, and p1238. also a open circuit on MIL code, wondering if ecu harness has issues..?


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## AutoTech1971 (Mar 31, 2011)

The fuel injectors share a common 12v hot wire. The ground side is switched by the ecu. You will need a multi meter and a wiring diagram for the pin out at the ecu. Disconnect harness at ecu and check for a open or shorted wire. 

If #1 plug is wet and car smoking you have a shorted wire as this will cause fuel to be dumped into the cylinder constantly. No fuel is the sign of a broken wire. 

Figure out which wire and pin is the issue and overlay a new wire from the ecu connector to the injector connector. That's the quickest and easiest. Cut you harness a couple inches back so that you don't have to remove and replace the pins. Have seen this several times in the past.


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## Doctor Meat Does Housecalls (Aug 27, 2010)

Pin 96 on the ecu side? And which of the two wires in injector 1?

Purple im assuming?


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