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Home >> Ford >> 1996 >> Crown Victoria V8-4.6L CNG SOHC VIN 9 >> Repair and Diagnosis >> Instrument Panel, Gauges and Warning Indicators >> Instrument Cluster / Carrier >> Testing and Inspection >> Pinpoint Tests >> C: Fuel Level Reads Inaccurately

C: Fuel Level Reads Inaccurately

Pinpoint Test C - Fuel Level Reads Inaccurately

NOTE: Ford DOES NOT provide a procedure to perform the following pinpoint test without the Rotunda Breakout Box 014-00322 and Rotunda Instrument Gauge Tester 014-R1063 or equivalents.

C1 - Check For Damaged Connector Or Terminals

- Turn ignition switch to OFF.
- Disconnect fuel indication module, inspect terminals and connector for damaged or pushed out pins.

Are any pins or terminals pushed out or damaged?

YES SERVICE as required. RESTORE vehicle. RETEST system.
NO GO to C2.

C2 - Check B+ Supply To Fuel Indication Module (FIM)

- Ignition switch OFF.
- Disconnect fuel indication module.
- Install Rotunda Breakout Box 014-00322 or equivalent to fuel indication module harness. Leave fuel indication module disconnected.
- Turn ignition switch to RUN.
- Using a voltmeter, measure the voltage between breakout box pin 37 or 57 and 40 or 60.

Is voltage greater than 10.5 volts?

YES GO to C4.
NO GO to C3.

C3 - Check Fuel Indication Module Ground

- Using an ohmmeter connected to a known good chassis ground, connect the second lead to breakout box Pin 40 or 60.

Is the resistance less than 5 ohms?

YES SERVICE circuit 361 (R) for open. RESTORE vehicle. RETEST system.
NO SERVICE circuit 570 (BK/W) for open. RESTORE vehicle. RETEST system.

C4 - Check Instrument Cluster Ground

- Turn ignition switch to OFF.
- Connect fuel indication module to harness and breakout box connection.
- Using an ohmmeter, measure the resistance between breakout box pin 31 and pin 40 or 60.

Is resistance less than 5 ohms?

YES GO to C5.
NO REPLACE fuel indication module. RESTORE vehicle. RETEST system.

C5 - Check B+ Supply To Instrument Cluster

- Turn ignition switch OFF.
- Disconnect instrument cluster connectors C1 and C2.

- Turn ignition switch to RUN.
- Using a voltmeter, measure the voltage between breakout box pin 12 and 40 or 60.

Is voltage greater than 10.5 volts?

YES GO to C6.
NO GO to C7.

C6 - Check For Voltage At Instrument Cluster Connectors

- Using a voltmeter connected to a known good ground, measure the voltage on circuit 231 (BK/Y) at instrument cluster connector pins C1-3 and C2-6.

Is the voltage greater than 10.5 volts?

YES GO to C8.
NO SERVICE open in circuit 231 (BK/Y). RESTORE vehicle. RETEST system.

C7 - Check Circuit 231 (BK/Y) For Short To Ground

- Turn ignition switch OFF.
- Using an ohmmeter, measure the resistance between breakout box pin 12 and pin 40 or 60.

Is the resistance greater than 10,000 ohms?

YES REPLACE fuel indication module. RESTORE vehicle. RETEST system.
NO SERVICE circuit 231 (BK/Y) for short to ground. RESTORE vehicle. RETEST system.

C8 - Check Circuit 570 (BK/W)

- Turn ignition switch to OFF.
- Using an ohmmeter, measure the resistance of circuit 570 (BK/W) between instrument cluster connector pin C1-2 and breakout box pin 31.

Is the resistance less than 5 ohms?

YES GO to C9.
NO SERVICE open in circuit 570 (BK/W). RESTORE vehicle. RETEST system.

C9 - Check Circuit 29 (Y/W)

- Using an ohmmeter, check resistance of circuit 29 (Y/W) between breakout box pin 38 and instrument cluster connector pin C1-1.

Is resistance less than 5 ohms?

YES GO to C10.
NO SERVICE open in circuit 29 (Y/W). RESTORE vehicle. RETEST system.

C10 - Check Circuit 29 (Y/W) For Short To B+

- Ignition switch OFF.
- Instrument cluster connectors disconnected.
- Using a voltmeter, measure the voltage between breakout box pin 38 and pin 40 or 60.

Is the voltage less than 0.5 volt?

YES GO to C11.
NO SERVICE circuit 29 (Y/W) for a short to B+. RESTORE vehicle. RETEST system.

C11 - Check Circuit 29 (Y/W) For Short To Ground

- Disconnect fuel indication module.
- Using an ohmmeter connected to a known good ground, connect the second lead to pin C1-1, circuit 29 (Y/W) of instrument cluster connector and check resistance to ground.

Is resistance greater than 10K ohms?

YES GO to C12.
NO SERVICE circuit 29 (Y/W) for short to ground. RESTORE vehicle. RETEST system.

C12 - Check Gauge Low Reading

- Turn ignition switch to OFF.
- Disconnect fuel indication module, leave breakout box connected to fuel indication module harness.
- Install a jumper between breakout box pins 37 and 12, also between 31 and 40.
- Connect one lead of Rotunda Instrument Gauge Tester 014-R1063 or equivalent to breakout box pin 38 and connect the second lead to pin 60.
- Set gauge tester to 22 ohms.
- Turn ignition switch to RUN, wait 60 seconds and read the fuel gauge.

Does fuel gauge read empty?

YES GO to C14.
NO GO to C13.

C13 - Recheck Low Test Results

- Turn ignition switch to OFF.
- Turn ignition switch to RUN.
- Tap lightly on instrument cluster, wait 60 seconds and read fuel gauge.

Does fuel gauge read EMPTY?

YES GO to C15.
NO REPLACE fuel gauge. RESTORE vehicle. RETEST system.

C14 - Check Gauge High Reading

- Turn ignition switch to OFF.
- Disconnect fuel indication module, leave breakout box connected to fuel indication module harness.
- Install ajumper between breakout box pins 37 and 12, then between 31 and 40.
- Connect one lead of Rotunda Instrument Gauge Tester 014-R1063 or equivalent to breakout box pin 38 and connect the second lead to pin 60.
- Set gauge tester to 145 ohms.
- Turn ignition switch to RUN, wait 60 seconds and read the fuel gauge.

Does fuel gauge read FULL?

YES GO to C15.
NO REPLACE fuel gauge. RESTORE vehicle. RETEST system.

C15 - Check Anti-Slosh Module

- Turn ignition switch to OFF.
- Disconnect fuel indication module, leave breakout box connected to fuel indication module harness.
- Install a jumper between breakout box pins 37 and 12, then between 31 and 40.
- Connect one lead of Rotunda Instrument Gauge Tester 014-R1063 or equivalent to breakout box pin 38 and connect the second lead to pin 60.
- Set gauge tester to 56 ohms.
- Turn ignition switch to RUN, wait 60 seconds and read the fuel gauge.

Is low fuel indicator ON?

YES REPLACE anti-slosh module. RESTORE vehicle. RETEST system.
NO GO to C16.

C16 - Check Gauge And Indicator

- Turn ignition switch to OFF.
- Reset tester to 33 ohms. Turn ignition switch to RUN. Wait 60 seconds and read fuel gauge.

Is indicator ON and gauge showing 118 of a tank?

YES Anti-slosh module operating properly. RESTORE vehicle. RETEST system.
NO GO to C17.

C17 - Check Indicator Circuitry

- With ignition switch in the RUN position, ground indicator circuit 29 (Y/W) between indicator and anti- slosh module.

Is low fuel indicator ON?

YES REPLACE anti-slosh module. RESTORE vehicle. RETEST system.
NO GO to C18.

C18 - Check Low Fuel Indicator Bulb

- Turn ignition switch to OFF.
- Remove instrument cluster as outlined.
- Remove low fuel indicator bulb and check bulb for continuity using an ohmmeter.

Does bulb test OK?

YES GO to C19.
NO REPLACE damaged bulb. RESTORE vehicle. RETEST system.

C19 - Check Circuit 29 (Y/W) For Open

- Using an ohmmeter, measure the resistance of circuit 29 (Y/W) from breakout box pin 38 to instrument cluster connector pin C1-1.

Is the resistance 5 ohms or less?

YES SERVICE circuit 29 (Y/W) for open. RESTORE vehicle. RETEST system.
NO REPLACE instrument cluster flex circuit. RETEST system.
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