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Engine Light vs. "Check" Engine Light

9052 Views 10 Replies 6 Participants Last post by  galvinm6
My original dash cluster was one without a tachometer, so I recently switched the original one with one from a junked F150 that had a tachometer. Along with this new tachometer came a brand new and frightening light.

the ENGINE light

This light constantly stays on. And I honestly cannot tell you why because I do not know what the hell this light indicates.

All I know is what my friend has told me and that is if this light is on dont F****** drive your car.

The oil pressure does drop to around five psi at idle and I know that low oil pressure sends this bad boy off. BUT when I give it gas and the oil pressure spikes from 40 to 60 this damn light stay on. And I know that at that oil pressure that light should at least flicker off and came back on when the oil pressure drops at idle again.

One theory is that because I have after market gauges for oil pressure and water temperature the computer is thinking that the oil pressure is constantly at 0psi and the temperature is constantly a 0*F.

All Im really sure is that I can find out what to do until I know what that damn light is for.
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Do a code check and see if you can find the problem that way.
Is that the stock gauges that are acting up? The gauges on the new cluster may be toast.
What yr was the F150?
ya i think its wut u think it is. my Engine light is always on because i put aftermarket temp and oil pressur gauges on. leaving the wires that go to the computer off it jsut telling the comp something is very wrong. it doesnt actually throw a code and doesnt do anything else as far as i know. the check engine light will come on if codes are present and thats the one u should care about since that light will never turn off.
Anyone have some information as to the purpose of the ENGINE light
One theory is that because I have after market gauges for oil pressure and water temperature the computer is thinking that the oil pressure is constantly at 0psi and the temperature is constantly a 0*F.
I believe that may be the case. since you have a sensor from your original dash that would tell it "hey your pressure is at 10 turn the light on" its now forever going to read 0 because it is no longer attached to that gauge. BUT another situation here is, @ 5psi your engine is choking itself looking for oil. If your gauge is correct your motor may be on its way out. The piston rings in the big ford v8's tend to go bad, and thats the sign right there is low oil pressure, then it raising when throttle is applied and RPMs increase.

Regardless, I believe that what is goin on here is that since your stock gauges are no longer hooked up, its going to read "ENGINE" until you pull the light out behind the dash, or find a way to jerry rig it to your OEM cluster or gauge to turn off.
wait, are you using aftermarket mechanical gauges for the oil and temp that you but at an auto parts store? or are you using the the guage cluster you jsut put in connected tot he stock sensors? i assume you are using the aftermarket guages since you know how many PSI your engine is running at

if you are using the aftermarket mechanicl guages, im assuming you have the wires that go to the stock sensors still unplugged and hanging down since you dont have anything going to them. as long as you have those wires disconnected, its gonna have that light on. your gonna have to find some way to rig that light to stay off, take that light out cause its gonna be useless if it stays on all the time anyways, or ignore it. i heard that theres suppose to be a kit for those gaugses that will inclued a T so you can use the mechanical guages and the stock ones together but i never bothered looking for them.

if you are using the new gauge cluster with stock sensors and that lights on, you may have to buy new sensors that match the vehicle you got the guages from and find a way to adapt and that might still not work.
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yo G!
What year F 150 is the cluster from?
Some basic info for now;
The Emission Maintenance Warning "EMW" module operates a light that
is located on the instrument panel. For 1985-87 model year vehicles,
the light will display the word "EMISSIONS". For 1988-89 model year
vehicles, the light will display the words "CHECK ENGINE". When the
light is lit, it is indicating that the 60,000 mile emission maintenance
should be performed
. After the maintenance is performed the EMW
module must be reset to zero time. Another type of module is the "IMS"
module. This module is not part of the light circuit and does not require
maintenance. At a predetermined time, the IMS module directs the EEC
IV processor to make a strategy change. A third type of module is the
"COMBO" module. This module combines the functions of the IMS and
the EMW modules.
TSB 88-05-7 Malfunction Indicator Light (MIL) Introduction
MARCH 2, 1988
ISSUE: The Malfunction Indicator Light (MIL) is a new feature that has been added to 1988 vehicles. Vehicle applications follow. The MIL's (Check Engine) is active when the engine system requires service. An explanation of how and when the Malfunction Indicator Light (MIL) operates may need to be explained to some vehicle owners.
ACTION: Use the following service information to explain the operation of the Malfunction Indicator Light (MIL) to resolve customer concerns.
Vehicles Equipped with EEC IV
The CHECK ENGINE light will come on while engine is operating in Failure Mode Effects Management (FMEM) or Hardware Limited Operation Strategy (HLOS) modes. The light will stay on as long as the fault causing it is present. In FMEM mode, the computer is receiving a sensor signal that is outside the limits set by the calibration strategy. In this mode, the computer uses an alternate strategy to maintain reasonable vehicle operation in spite of the fault. The following chart lists the system faults which will turn on the CHECK ENGINE light in this mode. The error code associated with this system fault is stored in Keep Alive Memory (KAM). If the fault is no longer present, the light will turn off and vehicle will return to normal vehicle strategy. The error code stored when the light was on was not erased. This code is one of the continuous error codes and can be accessed by running the KOEO self-test. HLOS mode is used when the system fault(s) is too extreme for the FMEM mode to handle. In HLOS mode, all software operations have stopped and the computer is running on hardware control only. The default strategy for this mode has a minimal calibration just to allow the vehicle to operate until it can be serviced.
The MIL light is turned on as a bulb check when the ignition key is first turned "ON". The EEC IV computer turns off the bulb as soon as it receives the PIP (crank) signal. If the light stays on during cranking, the computer is not receiving the PIP signal.
To service a MIL concern, use the 1988 Engine/Emission Diagnosis Shop Manual, Volume H, Section 16. If the vehicle has no drive problems, the MIL is on, and no codes are found in memory, follow diagnostics by symptom in the 1988 Engine/Emission Diagnosis Shop Manual, Volume H, Sections 17 or 18.
Non-EEC IV Vehicles
The Malfunction Indicator Light (MIL) alerts the customer that 60,000 mile emission system maintained is required. To service a MIL concern on a non-EEC IV vehicle, refer to the 1988 Engine/Emission Diagnostic Shop Manual, Volume H, Section 13.
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Its not the "CHECK ENGINE" its just the "ENGINE". Its the oh shit light when you have no oil...
The "Engine" light performs the same function as a "Check Gauges" light.
It's on because your running aftermarket gauges and disconnected your factory ones.

Just pull the bulb and be done with it. :thumbup
Here is we creep up to differences in EEC and Warning Lights & Indicators.

Electronic Engine Control History, Ford; In 1978: "...Ford Motor Company introduces its first “Electronic Engine Control (EEC-I)” system. This system was very limited in the control of engine functions and only controlled ignition timing, EGR flow and the air pump's injection of air into the exhaust.
1979: Ford introduces the EEC-II system. This system added air/fuel ratio control (feedback carburetor), throttle kicker (controls engine idle speed during start up and AC function) and canister purge control to the ECC-I system.
1980: Ford introduces the EEC-III system. This system included all the sensors used by the ECC-II system, with the addition of a temperature Sensor.

1980: In addition to the EEC-III system, Ford introduced another computer control system, called the “Microprocessor Control Unit (MCU)”. This system was used on a limited number of Ford vehicles up until 1991.

In 1981, the ECC-III system was modified to include controls for the new Electronic Fuel Injection systems. The EEC-III system was used on some models of Ford vehicles until 1984.

1983: Ford introduces the “Electronic Engine Control - IV (EEC-IV)” system. This system is capable of controlling a larger number of sensors, switches and actuators, and was used on a greater number of Ford vehicles. The ECC-IV system was used from 1983 to 1995.

1994: Ford introduces the EEC-V system (OBD-II). This is a highly sophisticated system that uses more special programs to enhance the computer's capability to monitor, detect and report failures, especially to the vehicle's emission system. This system was introduced on a limited number of 1994 and 1995 vehicles.

Starting in 1996, all Ford vehicles (cars and light trucks) sold in the US are equipped with the EEC-V system..."
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Im pretty sure that its my aftermarket gauges. Ive already put my stock temperature guage back up.

The aftermarket guages that are in my truck I did not put in and I just found out that they fact are NOT mechanical. they are electrical and run off of the stock switches.
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