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16.RESISTANCE IN THE (K900) SENSOR GROUND CIRCUIT
Measure the resistance of the (K900) Sensor ground circuit from the
MAP Sensor harness connector to the appropriate terminal of special
tool #8815.
Is the resistance below 5.0 ohms?
Ye s>>
Go To 17
No>>
Repair the excessive resistance in the (K900) Sensor
ground circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to
9 - ENGINE - STANDARD PROCEDURE)
17.PCM
NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal
push out. Repair as necessary.
Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and
Ground circuits.
Were there any problems found?
Ye s>>
Repair as necessary.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Replace and program the Powertrain Control Module per Service Information.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
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When Monitored:
Ignition on and engine running with no MAP Sensor DTCs.
Set Condition:
A large vacuum leak has been detected or both of the TP Sensors have failed based on their position being
2.5 volts and the calculated MAP value is less than the Gas Flow Adaptation value is too high. One trip fault
the code will set within 5 seconds. ETC light will flash.
Possible Causes
VACUUM LEAK
RESISTANCE IN THE (F856) 5-VOLT SUPPLY CIRCUIT
(F856) 5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND
RESISTANCE IN THE (K1) MAP SIGNAL CIRCUIT
(K1) MAP SIGNAL CIRCUIT SHORTED TO GROUND
RESISTANCE IN (K900) SENSOR GROUND CIRCUIT
RESISTANCE IN THE (F855) 5-VOLT SUPPLY CIRCUIT
(F855) 5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND
RESISTANCE IN THE TP SENSOR SIGNAL CIRCUIT
TP SENSOR SIGNAL CIRCUIT SHORTED TO GROUND
RESISTANCE IN THE (K922) TP SENSOR RETURN CIRCUIT
MAP SENSOR
TP SENSOR
PCM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING).
Diagnostic Test
1.ACTIVE DTC
NOTE: The most likely cause of this DTC is a vacuum leak.
NOTE: Diagnose any 5-Volt Supply, TP Sensor, Oxygen Sensor, Fuel related,or MAP Sensor DTCs before
continuing.
NOTE: The throttle plate should be free from binding and carbon build up.
Ignition on, engine not running.
With a scan tool, read DTCs.
Is the DTC active at this time?
Ye s>>
Go To 2
No>>
Refer to the INTERMITTENT CONDITION Diagnostic Procedure.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
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2.VACUUM LEAK
NOTE: This code is enabled on engines with a plastic intake manifold and is intendedtolimitthemaximum
engine speed if a large crack occurs.
NOTE: A large vacuum leak is most likely the cause of this DTC.
Inspect the Intake Manifold and Throttle body for leaks and cracks.
Inspect the Power Brake Booster for any vacuum leaks.
Inspect the PCV system for proper operation or any vacuum leaks.
Inspect the MAP Sensor for proper installation.
Were any vacuum leaks found?
Ye s>>
Repair the vacuum leak as necessary.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 3
3.MAP SENSOR OPERATION
Start the engine.
With a scan tool, monitor the MAP Sensor voltage.
Snap the Accelerator pedal.
Does the MAP Sensor voltage vary from below 2.0 volts at idle to above 3.5 volts at Wide Open Throt-
tle?
Ye s>>
Go To 4
No>>
Go To 11
4.TP SENSOR OPERATION
Ignition on, engine not running.
With a scan tool, perform the Throttle Follower Test.
TP Sensor No.1 should start at approximately 0.8 of a volt and increase to 4.2volts.
TP Sensor No.2 should start at approximately 4.2 volts and decrease to 0.8 ofavolt.
Is the voltage transition smooth between the appropriate values?
Ye s>>
Refer to the INTERMITTENT CONDITION Diagnostic Procedure.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 5
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7.TP SENSOR
Connect the C2 PCM harness connector.
Ignition on, engine not running.
With a scan tool, monitor the TP Sensor voltage.
Connect a jumper wire between the (K22) TP Sensor No.1 Signal circuit
and the (K922) Sensor Return circuit in the Throttle Body harness con-
nector.
TP Sensor No.1 voltage should start at approximately 4.8 volts and
decrease to 0.2 of a volt.
Connect a jumper wire between the (K122) TP Sensor No.2 Signal cir-
cuit and the (F855) 5-volt Supply circuit in the Throttle Body harness
connector.
TP Sensor No.2 voltage should start at approximately 0 volts and
increase to 4.8 to 5.2 volts.
Does the TP Sensor voltage change to the appropriate voltage
with the jumper wire installed?
Ye s>>
Disconnect the Battery before replacing the Throttle Body
Assembly. Replace the ThrottleBody Assembly. After instal-
lation is complete, use a scan tool and select the ETC
RELEARN function
Perform the POWERTRAIN VERIFICATION TEST. (Refer to
9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 8
8.RESISTANCE IN THE TP SENSOR SIGNAL CIRCUIT
Turn the ignition off.
Disconnect the C2 PCM harness connector.
Measure the resistance of the (K22) and (K122) TP Signal circuits from
the Throttle Body harness connector to the appropriate terminals of spe-
cial tool #8815.
Is the resistance below 5.0 ohms for each circuit?
Ye s>>
Go To 9
No>>
Repair the excessive resistance in the (K22) or (K122) TP
Sensor Signal circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to
9 - ENGINE - STANDARD PROCEDURE)
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9.TP SENSOR SIGNAL CIRCUIT SHORTED TO GROUND
Measure the resistance between ground and the (K22) and (K122) TP
Signal circuits at the Throttle Body harness connector.
Is the resistance above 100k ohms for each circuit?
Ye s>>
Go To 10
No>>
Repair the short to ground in the (K22) or (K122) TP Sen-
sor Signal circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to
9 - ENGINE - STANDARD PROCEDURE)
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10.RESISTANCE IN THE (K922) SENSOR RETURN CIRCUIT
Measure the resistance of the (K922) Sensor Return circuit from the
Throttle Body harness connector to the appropriate terminal of special
tool #8815.
Is the resistance below 5.0 ohms?
Ye s>>
Go To 17
No>>
Repair the excessive resistance in the (K922) Sensor
Return circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to
9 - ENGINE - STANDARD PROCEDURE)
11 .RESISTANCE IN THE (F856) 5-VOLT SUPPLY CIRCUIT
Turn the ignition off.
Disconnect the MAP Sensor harness connector.
Disconnect the C1 PCM harness connector.
CAUTION: Do not probe the PCM harness connectors. Probing the
PCM harness connectors will damage the PCM terminals resulting
in poor terminal to pin connection. Install Miller Special Tool #8815
to perform diagnosis.
Measure the resistance of the (F856) 5-volt Supply circuit from the MAP
Sensor harness connector to the appropriate terminal of special tool
#8815.
Is the resistance below 5.0 ohms?
Ye s>>
Go To 12
No>>
Repair the excessive resistance in the (F856) 5-volt Supply
circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to
9 - ENGINE - STANDARD PROCEDURE)
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12.(F856) 5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND
Measure the resistance between ground and the (F856) 5-volt Supply
circuit in the MAP Sensor harness connector.
Is the resistance above 100k ohms?
Ye s>>
Go To 13
No>>
Repair the short to ground in the (F856) 5-volt Supply cir-
cuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to
9 - ENGINE - STANDARD PROCEDURE)
13.MAP SENSOR
Connect the C1 PCM harness connector.
Ignition on, engine not running.
With a scan tool, monitor the MAP Sensor voltage.
Connect a jumper wire between the (K1) MAP Signal circuit and the
(K900) Sensor ground circuit in the MAP Sensor harness connector.
Cycle the ignition switch from off to on.
With a scan tool, monitor the MAP Sensor voltage.
Does the scan tool display MAP voltage from approximately 4.9
volts to below 0.5 volt with the jumper wire installed?
Ye s>>
Replace the MAP Sensor.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to
9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 14
NOTE: Remove the jumper wire before continuing.
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14.RESISTANCE IN THE (K1) MAP SIGNAL CIRCUIT
Turn the ignition off.
Disconnect the C2 PCM harness connector.
Measure the resistance of the (K1) MAP Signal circuit from the MAP
Sensor harness connector to the appropriate terminal of special tool
#8815.
Is the resistance below 5.0 ohms?
Ye s>>
Go To 15
No>>
Repair the excessive resistance in the (K1) MAP Signal cir-
cuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to
9 - ENGINE - STANDARD PROCEDURE)
15.(K1) MAP SIGNAL CIRCUIT SHORTED TO GROUND
Measure the resistance between ground and the (K1) MAP Signal cir-
cuit at the MAP Sensor harness connector.
Is the resistance above 100k ohms?
Ye s>>
Go To 16
No>>
Repair the short to ground in the (K1) MAP Signal circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to
9 - ENGINE - STANDARD PROCEDURE)