Trip Computer - Inaccurate

90ford05

TRIP COMPUTER - DISPLAYS INACCURATE AVERAGE FUEL ECONOMY AND DISTANCE TO EMPTY READINGS - 3.0L LX MODELS BUILT BEFORE 1/12/90

Article No. 90-5-5

FORD: 1990 PROBE


ISSUE: The trip computer may display inaccurate average fuel economy and distance to empty information. The calculations may be about 50-75% higher than actual. This occurs because the trip computer misinterprets the signal from the engine.

ACTION: Modify the computer circuitry by removing a resistor. Refer to the following procedure for service details.

1. Remove the trip computer display assembly. Refer to the 1990 Probe Shop Manual, Page 33-61-13 for the removal procedure.

2. Position the display assembly on a clean work area.

3. Remove the four (4) screws holding the metal cover. Carefully remove the cover and put the screws in it for use later.

4. Place the display window face down on the work table surface.

Figure 1:

5. Locate the first resistor # R212 located to the right of the divider block, Figure 1. The number R212 is printed to the top of the resistor. It is color coded YELLOW, PURPLE, RED and GOLD.

6. Use a felt tip marker on the resistor to identify it for removal.

7. Use a small X-Acto type knife to remove the resistor from the circuit board.

Figure 2:

NOTE: CAREFULLY CUT THROUGH THE R212 SOLDER/WIRE CONNECTION, ONE SIDE AT A TIME, FIGURE 2. THROW AWAY THE RESISTOR AFTER REMOVAL.

8. Position the metal cover over the display assembly.

NOTE: BE SURE TO PROPERLY POSITION THE RUBBER WIRE GROMMET INTO THE COVER CUT-OUT, THEN INSTALL THE SCREWS.

9. After the display is assembled, write the I.D. code KA-38 on the top of the metal cover with a felt tip marker.

10. Install the display assembly in the instrument panel. Refer to the 1990 Probe Shop Manual, Page 33-61-13 for the installation procedure.

11. Turn the ignition to the ON position. Check the display for illumination and display of DTE, AVG ECON, etc.

OTHER APPLICABLE ARTICLES: None
WARRANTY STATUS: Eligible Under Basic Warranty Coverage
OPERATION DESCRIPTION TIME
900505A Remove Resistor 0.9 Hr.
DEALER CODING
BASIC PART NO. CONDITION CODE
10D929 09
OASIS CODES: 2300, 2400