Page 265 of 5267

3.(B222) VEHICLE SPEED NO.2 SIGNAL CIRCUIT SHORTED TO VOLTAGE
Turn the ignition off.
Disconnect the ABS Module 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.
Ignition on, engine not running.
Measure the voltage of the (B222) Vehicle Speed No.2 Signal circuit at
the appropriate terminals of special tool #8815.
Is the voltage above 6.0 volts?
Ye s>>
Repair the short to voltage in the (B222) Vehicle Speed
No.2 Signal circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to
9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 4
4.(B222) VEHICLE SPEED NO.2 SIGNAL CIRCUIT OPEN
Turn the ignition off.
Measure the resistance of the (B222) Vehicle Speed No.2 Signal circuit
from the ABS Module harness connector to the appropriate terminal
special tool #8815.
Is the resistance below 5.0 ohms?
Ye s>>
Go To 5
No>>
Repair the open in the (B222) Vehicle Speed No.2 Signal
circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to
9 - ENGINE - STANDARD PROCEDURE)
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5.(B222) VEHICLE SPEED NO.2 SIGNAL CIRCUIT SHORTED TO GROUND
Measure the resistance between ground and the (B222) Vehicle Speed
No.2 Signal circuit at the appropriate terminals of special tool #8815.
Istheresistancebelow100ohms?
Ye s>>
Repair the short to ground in the (B222) Vehicle Speed
No.2 Signal circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to
9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 6
6.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)
Page 267 of 5267

P2166-ACCELERATOR PEDAL POSITION SENSOR 1 MAXIMUM STOP
PERFORMANCE
For a complete wiring diagramRefer to Section 8W.
When Monitored:
Ignition on. During in plant mode the APP Sensors need to be checked to make sure that idle and full pedal
travelcanbereachedonbothsensors.
Set Condition:
APPS No.1 has failed to achieve the required maximum value during In Plant testing. One trip fault and the
code will set within 5 seconds. Engine will only idle.
Possible Causes
IN PLANT TEST FAILURE
APPS RELEARN
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING).
Diagnostic Test
1.IN PLANT TEST FAILURE
Ignition on, engine not running.
NOTE: This DTC is set when the APP Sensors are learned in plant but do not reach the Minimum or Max-
imum voltage range.
With a scan tool read DTCs.
With the scan tool, erase DTCs.
Start the engine.
With the 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)
2.APPS RELEARN
With a scan tool select the ETC RELEARN function.
Next, erase DTCs.
Start the engine.
Does the DTC return?
Ye s>>
Replace the APPS Assembly per Service Information. After installation iscomplete, use a scan tool and
select the ETC RELEARN function.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Te s t C o m p l e t e .
Page 268 of 5267

P2167-ACCELERATOR PEDAL POSITION SENSOR 2 MAXIMUM STOP
PERFORMANCE
For a complete wiring diagramRefer to Section 8W.
When Monitored:
Ignition on. During in plant mode the APP Sensors need to be checked to make sure that idle and full pedal
travelcanbereachedonbothsensors.
Set Condition:
APPS No.2 has failed to achieve the required maximum value during In Plant testing. One trip fault and the
code will set within 5 seconds. Engine will only idle.
Possible Causes
IN PLANT TEST FAILURE
APPS RELEARN
Diagnostic Test
1.IN PLANT TEST FAILURE
Ignition on, engine not running.
NOTE: This DTC is set when the APP Sensors are learned in plant but do not reach the Minimum or Max-
imum voltage range.
With a scan tool read DTCs.
With the scan tool, erase DTCs.
Start the engine.
With the 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)
2.APPS RELEARN
With a scan tool select the ETC RELEARN function.
Next, erase DTCs.
Start the engine.
Does the DTC return?
Ye s>>
Replace the APPS Assembly per Service Information. After installation iscomplete, use a scan tool and
select the ETC RELEARN function.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Te s t C o m p l e t e .
Page 269 of 5267
P2172-HIGH AIRFLOW/VACUUM LEAK DETECTED (INSTANTANEOUS
ACCUMULATION)
Page 270 of 5267

For a complete wiring diagramRefer to Section 8W.
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 actual MAP minus an Offsetvalue.Onetripfaultand
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, Fuel System Lean or Rich, or MAP Sensor DTCs before con-
tinuing.
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)
Page 271 of 5267

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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5.RESISTANCE IN THE (F855) 5-VOLT SUPPLY CIRCUIT
Turn the ignition off.
Disconnect the Throttle Body harness connector.
Disconnect the C2 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 (F855) 5-volt Supply circuit from the
Throttle Body harness connector to the appropriate terminal of special
tool #8815.
Is the resistance above 100 ohms?
Ye s>>
Go To 6
No>>
Repair the excessive resistance in the (F855) 5-volt Supply
circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to
9 - ENGINE - STANDARD PROCEDURE)
6.(F855) 5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND
Measure the resistance between ground and (F855) 5-volt Supply circuit
at the Throttle Body harness connector.
Is the resistance above 100 ohms?
Ye s>>
Go To 7
No>>
Repair the short to ground in the (F855) 5-volt Supply cir-
cuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to
9 - ENGINE - STANDARD PROCEDURE)