DTC P0656 Fuel Level Output Circuit
The PCM controls the
fuel gauge through the fuel gauge control circuit. The PCM supplies a pulse
width modulated (PWM) duty cycle signal to control the fuel gauge. The PCM
receives the fuel level information from the fuel level sensor.
The PCM controls the
gauge by grounding the control circuit via an internal switch called a driver.
The primary function of the driver is to supply the ground for the controlled
component. Each driver has a fault line which the PCM monitors. If the fault
detection circuit senses a voltage other than what the PCM expects, the fault
line status changes causing the DTC to set.
Conditions
for Running the DTC
- The engine speed is greater than 600
RPM.
- The ignition voltage is between 6.0
volts and 16.0 volts.
Conditions
for Setting the DTC
- The PCM detects that the commanded
state of the driver and the actual state of the control circuit do not
match.
- All the above conditions present for
a minimum of 10 seconds.
Action
Taken When the DTC Sets
- The PCM stores the DTC information
into memory when the diagnostic runs and fails.
- The malfunction indicator lamp (MIL)
will not illuminate.
- The PCM records the operating
conditions at the time the diagnostic fails. The PCM stores this
information in the Failure Records.
Conditions
for Clearing the DTC
- A last test failed, or current DTC,
clears when the diagnostic runs and does not fail.
- A history DTC will clear after
40 consecutive warm-up cycles, if no failures are reported by this or
any other non-emission related diagnostic.
- Use a scan tool in order to clear
the DTC.
- An open GAGE fuse causes DTC P0656
to set. The instrument cluster is inoperative with an open GAGE fuse.
- The C210 connector half with the
female terminals is the gauge side of the circuit. The connector half with
the male terminals is the PCM side of the harness.
- The following may cause an
intermittent:
- Poor connections: Test for adequate
terminal tension. Refer to Intermittents and Poor Connections Diagnosis in
Wiring Systems.
- Corrosion
- Mis-routed harness
- Rubbed through wire insulation
- Broken wire inside the insulation
- Using the Freeze Frame and/or
Failure Records data may aid in locating an intermittent condition. If you
cannot duplicate the DTC, the information included in the Freeze Frame
and/or Failure Records data can help determine how many miles since the
DTC set. The Fail Counter and Pass Counter can also help determine how
many ignition cycles the diagnostic reported a pass and/or a fail. Operate
the vehicle within the same freeze frame conditions (RPM, load, vehicle
speed, temperature etc.) that you observed. This will isolate when the DTC
failed. For an intermittent condition, refer to Symptoms
.
The numbers below refer
to the step numbers on the diagnostic table.
- The C210 connector
is located behind the right side (passenger side) kick panel. Connector
C210 contain circuits for the fuel tank pressure
sensor and the fuel level sensor. Disconnecting this connector causes
additional DTCs to set.
If the gauge displays empty, this indicates
the circuit between the C210 connector and the gauge is shorted to ground or
the gauge is malfunctioning.
|
Step |
Action |
Value(s) |
Yes |
No |
|
Did
you perform the Powertrain On-Board Diagnostic
(OBD) System Check? |
-- |
|||
Is
DTC P0461, P0462, or P0463 also set? |
-- |
Go to Applicable DTC |
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|
Is
the Gages fuse open? |
-- |
Go to Instrument
Cluster System Check Instrument Panel, Gauges and Console |
||
Does
the fuel gauge respond? |
-- |
Go to Diagnostic Aids |
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|
Important Additional DTCs set when
connector C210 is disconnected. Disconnect
the 8-way C210 connector located behind the passenger side kick panel. Refer
to Lower
Right Side of IP in Wiring Systems. Does the fuel gauge display empty? |
-- |
|||
Did
you find and correct the condition? |
-- |
Go to Instrument
Cluster System Check Instrument Panel, Gauges and Console |
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|
Jumper
the fuel gauge control circuit (gauge side of C210 connector) to ground. Does
the fuel gauge display empty? |
-- |
|||
Does
the test lamp brightness change with each command? |
-- |
|||
Is
continuity indicated? |
-- |
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Does
the test lamp illuminate? |
-- |
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Does
the test lamp illuminate? |
-- |
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Is
continuity indicated? |
-- |
|||
Did
you find and correct the condition? |
-- |
Go to Diagnostic Aids |
||
|
Repair
the open fuel gauge control circuit between the PCM and the C210 connector.
Refer to Wiring
Repairs in Wiring Systems. Is the action complete? |
-- |
-- |
||
|
Repair
the grounded fuel gauge control circuit between the PCM and the C210
connector. Refer to Wiring
Repairs in Wiring Systems. Is the action complete? |
-- |
-- |
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|
Repair
the fuel gauge control circuit for a short to voltage between the PCM and the
C210 connector. Refer to Wiring
Repairs in Wiring Systems. Is the action complete? |
-- |
-- |
||
|
Repair
the open fuel gauge control circuit between the cluster and the C210
connector. Refer to Wiring
Repairs in Wiring Systems. Is the action complete? |
-- |
-- |
||
|
Repair
the fuel gauge control circuit for a short to voltage between the cluster and
the C210 connector. Refer to Wiring
Repairs in Wiring Systems. Is the action complete? |
-- |
-- |
||
Did
you find and correct the condition? |
-- |
|||
|
Important Program the replacement
PCM. Refer to PCM
Replacement/Programming . Replace
the PCM. Is the action complete? |
-- |
-- |
||
Does
the scan tool indicate that this test ran and passed? |
-- |
|||
|
Select
the Capture Info option and the Review Info option using the scan tool. Does
the scan tool display any DTCs that you have not diagnosed? |
-- |
Go to the applicable
DTC table |
System OK |