evr voltage??

If you have a paper clip, you can check the codes. If you don't have a paper clip, borrow a hair pin from the woman in your life (I guess they still use hair pins).

Dump the codes and see what the computer says is wrong…

Here's the link to dump the computer codes with only a jumper wire or paper clip and the check engine light, or test light or voltmeter. I’ve used it for years, and it works great.

See http://www.troublecodes.net/Ford/
OR
See http://www.dalidesign.com/hbook/eectest.html for more descriptive help
OR
See http://www.mustangworks.com/articles/electronics/eec-iv_codes.html

IF your car is an 86-88 stang, you'll have to use the test lamp or voltmeter method. There is no functional check engine light on the 86-88's except possibly the Cali Mass Air cars.

Codes have different answers if the engine is running from the answers that it has when the engine isn't running. It helps a lot to know if you had the engine running when you ran the test.

Trouble codes are either 2 digit or 3 digit, there are no cars that use both 2 digit codes and 3 digit codes.

For those who are intimidated by all the wires & connections, see http://www.actron.com/product_detail.php?pid=16153 for what a typical hand scanner looks like. Normal retail price is about $30 or so at AutoZone or Walmart.

Or for a nicer scanner see http://www.midwayautosupply.com/detailedproductdescription.asp?3829 – It has a 3 digit LCD display so that you don’t have to count flashes or beeps.. Cost is $33.

Use the first drawing for your connection, and that should work with the test light.

Code 35 EVR - EVP sensor signal is/was high – Bad sensor, or possible missing ground for EVR circuit. With the power off, measure the resistance between the black wire and battery ground. You should see less than 1 ohm. Check the same black wire on the EGR and MAP sensor. More than 1 ohm there and the wire is probably broken in the harness between the engine and the computer. The 10 pin connectors pass the black wire back to the computer, and can cause problems.

See the following website for some help from Tmoss (diagram designer) & Stang&2Birds (website host)

http://www.veryuseful.com/mustang/tech/engine/images/88-91eecPinout.gif

See http://fordfuelinjection.com/index.php?p=6 for more wiring help & 10 pin connector diagrams

Code 96 – KOEO- Fuel pump monitor circuit shows no power - Fuel pump relay or battery power feed was open - Power / Fuel Pump Circuits. The fuel pump lost power at some time while the ignition switch was in the run position.

Look for a failing fuel pump relay, bad connections or broken wiring. The fuel pump relay is located under the Mass Air Meter on Fox bodied stangs built after 91. On earlier model cars is under the passenger seat. On Mass Air Conversions, the signal lead that tells the computer that the fuel pump has power may not have been wired correctly. See http://www.stangnet.com/tech/maf/massairconversion.html

To help troubleshoot the 96 code , follow this link for a wiring diagram for 87-90 models http://www.veryuseful.com/mustang/tech/engine/images/fuel-alt-links-ign-ac.gif

for 91-93 models see http://www.autozone.com/images/cds/gif/large/0900823d80195960.gif

Look for power at the fuel pump - the fuel pump has a connector at the rear of the car with a pink/black wire and a black wire that goes to the fuel pump. The pink/black wire should be hot when the test connector is jumpered to the test position. . To trick the fuel pump into running, find the ECC test connector and jump the connector in the lower RH corner to ground. http://www.mustangworks.com/articles/electronics/eec-iv_codes.html for a description of the test connector. it. No voltage when jumpered, check the fuel pump relay and fuse links.

86-90 Models:
Using the diagram, check the red/black wire from the fuel pump relay: you should see 12 volts or so. If not, check the inertia switch: on a hatch it is on the drivers side by the taillight. Look for a black rubber plug that pops out: if you don't find it, then loosen up the plastic trim. Check for voltage on both sides of the switch. If there is voltage on both sides, then check the Pink/black wire on the fuel pump relay: it is the power feed to the fuel pump. Good voltage there, then the fuel pump is the likely culprit since it is getting power. No voltage there, check the Orange/Lt blue wire, it is the power feed to the fuel pump relay & has a fuse link in it. Good voltage there & at the Pink/black wire, swap the relay.

91-93 Models:
Using the diagram, check the dark green/yellow wire from the fuel pump relay: you should see 12 volts or so. If not the relay has failed or is intermittent. Check the inertia switch: on a hatch it is on the drivers side by the taillight. Look for a black rubber plug that pops out: if you don't find it, then loosen up the plastic trim. Check for voltage on both sides of the switch. If there is voltage on both sides, then check the Pink/black wire on the fuel pump relay: it is the power feed to the fuel pump. Good voltage there, then the fuel pump is the likely culprit since it is getting power. No voltage there, check the Pink/black wire, it is the power feed to the fuel pump relay & has a fuse link in it. Good voltage there & at the dark green/yellow wire, swap the relay.