Pinpoint Test B: Incorrect Fuel Gauge Indication - Ford Mustang 2005 Workshop Manual

2005 Mustang Workshop Manual
P0463 — Fuel Level Sensor A Circuit High (LH
Side)
P2065 — Fuel Level Sensor B Circuit (RH
Side)
P2066 — Fuel Level Sensor B Circuit
Range/Performance (RH Side)
P2067 — Fuel Level Sensor B Circuit Low (RH
Side)
P2068 — Fuel Level Sensor B Circuit High
(RH Side)
Possible Causes
circuit 29 (YE/WH) short to circuit 1357 (LB/YE)
circuit 29 (YE/WH) open, short to ground or voltage
circuit 1356 (LG/VT) open, short to ground or voltage
circuit 1356 (LG/VT) short to circuit 1357 (LB/YE)
circuit 1357 (LB/YE) open or short to voltage
fuel pump module (LH side)
fuel level sensor (RH side)
fuel level sender (float and card)
SJB
fuel tank
instrument cluster

PINPOINT TEST B: INCORRECT FUEL GAUGE INDICATION

NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
NOTE: Once the repairs are complete, clear the instrument cluster DTCs.
B1 CARRY OUT THE COMMUNICATION NETWORK TEST
Ignition ON.
Enter the following diagnostic mode on the scan tool: Network Test.
Carry out the network test.
Does the SJB pass the network test?
B2 CARRY OUT THE INSTRUMENT CLUSTER FUEL GAUGE ACTIVE COMMAND USING THE SCAN
TOOL
Ignition ON.
Enter the following diagnostic mode on the scan tool: Instrument Cluster Active Command.
Select the instrument cluster fuel level control active command and scroll the fuel level at: 0%, 50%,
and 100%.
Does the fuel gauge needle start at empty (E), move to half at 50%, and full (F) at 100%?
B3 RETRIEVE THE RECORDED DTCs FROM THE CONTINUOUS MEMORY INSTRUMENT CLUSTER
SELF-TEST
NOTE: The instrument cluster DTCs are all set in continuous memory only. For all diagnostics, use
only the instrument cluster DTCs.
Check for recorded continuous memory instrument cluster DTCs from the self-test.
Are any instrument cluster DTCs recorded?
B4 CHECK THE FUEL SENDER FOR A SHORT TO GROUND
NOTE: The fuel pump module may also be called the fuel tank unit.
NOTE: The fuel level sensor may also be called the fuel sender.
Disconnect: Fuel Pump Module C433 (DTC B1204) (LH Side) or Fuel Level Sensor C434 (DTC
B2628) (RH Side).
Ignition ON.
Wait one minute.
Enter the following diagnostic mode on the scan tool: Instrument Cluster Self-Test.
NOTE: Make sure to use only the instrument cluster DTCs for this step. Once the repairs are
complete, clear the instrument cluster DTCs.
NOTE: It is normal for DTC B1204 or B2628 to be present during this step and should be ignored.
Clear the instrument cluster DTCs. Repeat the instrument cluster self-test.
Is DTC B1202 or B2627 retrieved?
B5 CHECK CIRCUITS 29 (YE/WH) OR 1356 (LG/VT) FOR A SHORT TO GROUND
Ignition OFF.
Disconnect: SJB C2280c.
For DTC B2628, measure the resistance between the SJB C2280c-43, circuit 29 (YE/WH) (DTC
B2628), harness side and ground
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Sets in the PCM when the PCM detects an open or short to voltage on the fuel pump module signal circuit based on the
messaged input received from the instrument cluster.
Sets when the PCM determines the value of the fuel level sensor input signal is stuck, that the fuel level input signal does not
change or does not correspond with the calculated fuel usage.
Sets when the PCM determines the fuel level sensor input signal repeatedly moves in and out of range, exceeding the minimum
or maximum allowable calibrated parameters for a specified fuel fill percentage in the fuel tank.
Sets in the PCM when the PCM detects a short to ground on the fuel level sensor signal circuit based on the messaged input
received from the instrument cluster.
Sets in the PCM when the PCM detects an open or a short to voltage on the fuel level sensor signal circuit based on the
messaged input received from the instrument cluster.
Test Step Result / Action to Take
Yes
GO to B2.
No
REFER to Section 418-00.
Yes
GO to B3.
No
GO to B23.
Yes
For DTC B1204 or DTC B2628, GO to B4.
For DTC B1202, GO to B8.
For DTC B2627, GO to B13.
For DTC B2879, GO to B18.
No
GO to B18.
Yes
To continue DTC B1204 diagnostics, GO to B21.
To continue DTC B2628 diagnostics, INSTALL a new fuel level
sensor. REFER to Section 310-01. CLEAR the DTCs. REPEAT
the self-test.
No
GO to B5.
Yes
For DTC B1204, GO to B6.
For DTC B2628, GO to B7.
No
REPAIR the circuit in question. CLEAR the DTCs. REPEAT the
self-test.
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11/14/2009