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Bob F

Bob F 11/8/2010

1998 Ford Econoline Super Duty Custom 8 Cyl 7.3L


This is a Diesel,I have a (po231) Fuel pump secondary circuit low and (P1284) injecter control pressure failure.

What do I need to do to fix it?

3 Answers

Fox Hound

Fox Hound 11/8/2010

For the P0231 i have an answer but the trail goes cold on the 1284

- Open Inertia Switch
- Blown Fuel Pump fuse
- Open Fuel Pump Monitor Circuit
- Open Fuel Pump Control Circuit
- Faulty Fuel Pump Relay
- Damaged PCM.

For some FORD models:
1. Disconnect the inertia switch harness connector.
2. Turn key to ON position (Engine OFF)
3. Measure voltage of circuit between inertia switch harness connector and ground.
4. If battery voltage is found, replaced Inertia Switch.
5. Clear codes.

Fox Hound

ref 11/9/2010

What isa inertia swith and were is it?thank you.

Fox Hound

ref 11/9/2010

The P1284 is to the ijecter controlpressure failure.(I got it from the scaner)


HouseCallAuto 11/8/2010

For the P1284 you need to get interactive with a few circuit tests.

1. Monitor the voltage on the Dark Blue/Light Green (DB/LG) wire at the Injection Control Pressure (ICP) sensor. The voltage should be roughly 0.2v Key On Engine Off and will increase to at least 0.8v normally with the engine iddling.

2. Monitor the voltage at the sensor and also on the scanner while wiggling the wire harness and the connections right at the sensor. If the voltage starts changing when wiggling the wires at the connector, replace the connector with an updated part #3C3Z-12224-AA.

3. If the voltage out of the sensor is steady when wiggling the connections, but the voltage on the scanner never changes, locate and repair the bad connection between the ICP sensor and pin #87 of the Powertrain Control Module (PCM) connector (start with checking for problems at C138, which is a 42-terminal connector near the left side valve cover).

4. If the voltage at the sensor intermittently just drops out and is not related to a bad connection, verify that the Brown/White (BR/WH) wire maintains 5v and the Gray/Red (GY/RD) wire is a good ground. If OK, suspect a faulty ICP sensor.

For the P0231, I need to know if this truck has a bad fuel pump fuse (30amp MAXI fuse) or have you found it blown and replaced it?


ref 11/9/2010

No I didnet change the fuel pump fuse.I never even looked at it.The moter runs ruff at idle ,no get up and go 35mph/55mph.I had it up to 70mph .runs good after 55,65mph.


ref 11/13/2010

The( DB/LG) tested out .04v key off but .05v key on.The resistance was (key off) was 1994 ohms.


ref 11/16/2010

I check the fuel pump fuse,OK. I changed out the ijecton control pressuer senser runs good after idle.Idles real ruff but runs good now(.I did clean the fuel tank out last month.) Dont know if that had any thing to do with it.

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