OBD (On Board Diagnostics) is an on-board diagnostic system on vehicles (cars and trucks). Currently used OBD-II (United States), EOBD (Europe), and JOBD (Japan) standard that provide almost complete control motor vehicle and other devices.

OBD I was the first OBD regulation requiring producers to install a monitoring system of some components of emission controls on automobiles. Required on all vehicles from 1991, OBD I systems were not as effective because they only monitor some of the related components emissions, and were not calibrated to a specific level of emissions.

The Ford Probe 24v 1993 until approximately mid-1995, incorporating the diagnostic system OBD-I, while the following Ford Probe years incorporate the OBD-II system

Reading codes explained below is directed to the Ford Probe 24v with system diagnostic OBD-I.


The indicator by which the electronic control of the car (PCM) indicates that some (or more) sensors and / or motor actuators are not working properly is similar to those shown in figures "Figure 1" (Ford Probe pre-restyling) and "Figure 2" (Ford Probe post-restyling).

Figure 1Figure 2

When this indicator is lit, the control unit stores the code of the car associated with this failure, it so even then the indicator turns off, the fault code will have been recorded on memory until it is reset.

It is worth mentioning that there are some fault codes that do not imply that turns on the witness fails. These codes are not registered in memory, so once fixed the problem, not becomes necessary to reset the electronic control. These error codes are related to the different motor solenoids (See error codes at end of document)


To proceed to read error codes, we have removed the key contact and locate in the engine compartment diagnostic connector. This is near the fuse box (Figure 3)

Figure 3

Once you locate the connector, will open its lid, and through a cable or clip connect pins TEN (top row, 2nd from the right) with GND (2nd row, 1st from left) (Figure 4)

Figure 4

When we made the bridge between the pins set, insert the key in the ignition, and we will turn 2 positions (just one before starting the engine).

At this point, we are the dashboard lights up in habitual witnesses, including "Check engine".

This witness, if the electronic control not detect any errors, or not have any memorized, after a few seconds off.

If the control unit detects an error, or errors have memorized, represented by the intermittent witness "Check engine" using the following code:

- Long pulses (1.6 seconds lighting) represent tens
- Short pulses (0.4 seconds lighting) represent units

Thus, for example, 2 long pulses and 3 short pulses represent code 23.

When we finish reading the codes, will remove the ignition key and remove the bridge connector diagnosis.

To remove the code from memory, simply disconnect the negative terminal of the battery and hold the brake pedal for 20 seconds

Below is a list of error codes indicating the sensor or actuator that is affected

02NE2 crankshaft position sensorYES
03G camshaft position sensorYES
04NE1 camshaft/crankshaft position sensorYES
05Knock sensorYES
08Volume Air Flow sensor (VAF)YES
09Coolant temperature sensor (CTS)YES
10Intake air temperature sensor (IAT)YES
12Throttle position sensor (TPS)YES
14Barometric pressure sensorYES
15LHO2S inactivation errorYES
16Exhaust gas recirculation (EGR) systemYES
17LHO2S inversion errorYES
23RHO2S inactivation errorYES
24RHO2S inversion errorYES
25Fuel pressure regulator control solenoidNO
26Canister purge solenoidNO
28EGR vacuum solenoidNO
29EGR vent solenoidNO
34Idle air control (IAC) solenoidNO
41VRIS #1 solenoidNO
46VRIS #1 solenoidNO
67LFAN relay (1993 only)NO
69ECTF sensor (1993 only)YES


This information and more at: