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TEST ACTION APPLICABILITY
8 Ignition Off
Disconnect the PCM.
Note: Check connectors - Clean/repair as necessary.
Key on.
With a Voltmeter, measure voltage of the LDP Solenoid Control Circuit at the PCM
Connector.
Is the voltage above 10.0 volts?All
Ye s®Go To 9
No®Replace the LDP.
Perform Powertrain Verification Test VER-6A.
9 If there are no potential causes remaining, the PCM is assumed to be defective.
View repair options.All
Repair
Replace the PCM.
Perform Powertrain Verification Test VER-6A.
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P-1495 LEAK DETECTION PUMP SOLENOID CIRCUIT ÐContinued
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Symptom:
P-1496 5 VOLT SUPPLY OUTPUT TOO LOW
When Monitored and Set Condition:
P-1496 5 VOLT SUPPLY OUTPUT TOO LOW
When Monitored: With the ignition on.
Set Condition: The 5-volt supply to the sensors is below 3.5 volts for 4 seconds.
POSSIBLE CAUSES
5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND
5-VOLT SUPPLY WIRING HARNESS INTER DEF
A/C PRESSURE SENSOR DEFECTIVE
MAP SENSOR DEFECTIVE
THROTTLE POSITION SENSOR DEFECTIVE
PCM DEF (5 VOLT SUPPLY CIRCUIT)
TEST ACTION APPLICABILITY
1 Ignition On, Engine Not Running
Disconnect the Throttle Position Sensor Connector.
Note: Check connectors - Clean/repair as necessary
With a voltmeter, probe the 5-Volt Supply Ckt at the TP Sensor harness connector.
Note: Reconnect TPS Connector after measurement.
Is the voltage reading below 4.5 volts?All
Ye s®Go To 2
No®Go To 6
2 Ignition On, Engine Not Running.
Disconnect the Throttle Position Sensor Connector.
Disconnect the A/C Pressure Sensor.
Note: Check connectors - Clean/repair as necessary.
With a voltmeter, probe the TP Sensor 5-Volt Supply Circuit to the TP Sensor.
Is the 5-Volt Supply Circuit voltage above 4.0 volts?All
Ye s®Replace the A/C Pressure Sensor.
Perform Powertrain Verificaton Test VER-2A.
No®Go To 3
3 Ignition On, Engine Not Running
Disconnect the Throttle Position Sensor Connector.
Disconnect the MAP Sensor Electrical Connector.
Note: Check connectors - Clean/repair as necessary.
With the voltmeter, probe the TP Sensor 5-Volt Supply Circuit to the TP Sensor.
Is the 5-Volt Supply Circuit voltage above 4.0 volts?All
Ye s®Replace the Map Sensor.
Perform Powertrain Verification Test VER-2A.
No®Go To 4
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TEST ACTION APPLICABILITY
4 Ignition Off
Disconnect the Throttle Position Sensor Connector.
Disconnect the MAP Sensor Electrical Connector.
Disconnect the A/C Sensor Connector.
Disconnect the Powertrain Control Module Connector.
Note: Check connectors - Clean/repair as necessary.
With the ohmmeter, probe the 5-volt supply circuit at the TPS Connector.
Is the resistance below 5.0 ohms?All
Ye s®Repair the 5-volt Supply Circuit for a short to ground.
Perform Powertrain Verification Test VER-2A.
No®Go To 5
5 If there are no potential causes remaining, the Powertrain Control Module is
assumed to be defective.
View repair options.All
Repair
Replace the PCM.
Perform Powertrain Verification Test VER-2A.
6 Ignition On, Engine Not Running
Disconnect the MAP Sensor Connector.
Note: Check connectors - Clean/repair as necessary.
With the voltmeter, probe the 5-Volt Supply Ckt at the MAP Sensor Connector.
Is the voltage reading below 4.5 volts?All
Ye s®Replace the TPS.
Perform Powertrain Verification Test VER-2A.
No®Test Complete.
7 Ignition On, Engine Not Running
Disconnect the MAP Sensor Connector.
Note: Check connectors - Clean/repair as necessary.
With the DRB in voltmeter mode, probe the 5-volt supply circuit voltage at the MAP
Sensor Connector.
Wiggle all connectors and wiring to all sensors (MAP, A/C PRESS, TPS).
While you wiggle the connectors and wiring to all sensors monitor the 5.0 volt supply
circuit voltage.
Was there any voltage change?All
Ye s®Repair the harness or connector that caused the voltage change.
Perform Powertrain Verification Test VER-2A.
No®Test Complete.
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P-1496 5 VOLT SUPPLY OUTPUT TOO LOW ÐContinued
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Symptom:
P-1598 A/C PRESSURE SENSOR VOLTS TOO HIGH
When Monitored and Set Condition:
P-1598 A/C PRESSURE SENSOR VOLTS TOO HIGH
When Monitored: With the ignition on, the engine running, and the A/C relay energized.
Set Condition: The A/C pressure sensor signal at PCM cavity 42 goes above 4.9 volts.
POSSIBLE CAUSES
AIR CONDITIONING PRESSURE SENSOR GROUND CIRCUIT OPEN
AIR CONDITIONING PRESSURE SENSOR DEFECTIVE
A/C PRESS SENSOR CONN AND WIRING HARN INTER DAMAGE
A/C PRESSURE SENSOR CONNECTOR AND HARNESS OBSERVABLE DEFECT
A/C PRESSURE SENSOR SIGNAL CIRCUIT OPEN
A/C PRESSURE SENSOR SIGNAL SHORT TO VOLTAGE
PCM DEFECTIVE
TEST ACTION APPLICABILITY
1 Ignition On, Engine Not Running
With the DRB, read the A/C Pressure Sensor voltage.
Is the A/C Pressure Sensor voltage above 4.6 volts?All
Ye s®Go To 2
No®Go To 7
2 Ignition Off
Disconnect the A/C Pressure Sensor.
Note: Check connectors - Clean/repair as necessary.
Turn ignition on.
Using a Voltmeter, measure voltage of the A/C Pressure Signal Circuit to ground.
Is the voltage above 6.0 volts?All
Ye s®Repair A/C Pressure Sensor Signal shorted to voltage.
Perform Powertrain Verification Test VER-2A.
No®Go To 3
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TEST ACTION APPLICABILITY
3 Ignition Off
Disconnect the A/C Pressure Sensor.
Note: Check connectors - Clean/repair as necessary.
Connect a Jumper Wire between the A/C Pressure Sensor Signal Circuit and Sensor
Ground Circuit.
Ignition on with engine not running.
With the DRB, read the A/C Pressure Sensor voltage.
Is the voltage below 1.0 volt?All
Ye s®Replace the A/C Pressure Sensor.
Perform Powertrain Verification Test VER-2A.
No®Go To 4
4 Ignition Off
Disconnect the A/C Sensor Electrical Connector.
Note: Check connectors - Clean/repair as necessary.
Connect a Jumper Wire between the A/C Pressure Sensor Signal Circuit and Engine
Ground.
Ignition on, engine not running.
With the the DRB, read the A/C Pressure Sensor voltage.
Is the voltage below 1.0 volt?All
Ye s®Repair the open Sensor Ground Circuit.
Perform Powertrain Verification Test VER-2A.
No®Go To 5
5 Ignition Off.
Disconnect the A/C Pressure Sensor.
Note: Check connectors - Clean/repair as necessary.
Disconnect the PCM.
Using an Ohmmeter, measure the A/C Pressure Sensor Signal Circuit from the PCM
to the Sensor.
Is the resistance below 5.0 ohms?All
Ye s®Go To 6
No®Repair the open A/C Presure Sensor Circuit.
Perform Powertrain Verification Test VER-2A.
6 If there are no potential causes remaining, the PCM is assumed to be defective.
View repair options.All
Repair
Replace the PCM.
Perform Powertrain Verification Test VER-2A.
7 Ignition On, Engine Not Running.
With the DRB, read the A/C Pressure Sensor voltage.
Using the schematic as a guide, wiggle the A/C Pressure Sensor Connector and
Harness.
Monitor the DRB display.
Was there any A/C Pressure Sensor voltage change?All
Ye s®Repair the Harness or Connector that caused the voltage to
change.
Perform Powertrain Verification Test VER-2A.
No®Go To 8
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P-1598 A/C PRESSURE SENSOR VOLTS TOO HIGH ÐContinued
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TEST ACTION APPLICABILITY
8 Ignition Off
Using the schematic as a guide, inspect the Wiring and Connectors.
Were any problems found?All
Ye s®Repair as necessary.
Perform Powertrain Verification Test VER-2A.
No®Test Complete.
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DRIVEABILITY
P-1598 A/C PRESSURE SENSOR VOLTS TOO HIGH ÐContinued
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Symptom:
P-1599 A/C PRESSURE SENSOR VOLTS TOO LOW
When Monitored and Set Condition:
P-1599 A/C PRESSURE SENSOR VOLTS TOO LOW
When Monitored: With the ignition switch on, the engine running , and the A/C relay
energized.
Set Condition: The A/C pressure sensor signal voltage at PCM cavity 42 goes below 0.5
volt, or the voltage is below .059 volt.
POSSIBLE CAUSES
A/C PRESSURE SENSOR 5-VOLT SUPPLY CKT OPEN
A/C PRESS SEN CONN AND WIRING HARN OBSERVABLE DEF
A/C PRESSURE SEN SIG CKT SHORTED TO SEN GND CKT
A/C PRESSURE SENSOR CONN AND WIRING HARN INTER DEF
A/C PRESSURE SENSOR SIGNAL CKT SHORTED TO GND
A/C PRESSURE SENSOR DEFECTIVE
PCM DEF (A/C PRESSURE SEN)
TEST ACTION APPLICABILITY
1 Ignition On, Engine Not Running
With the DRB, read the A/C Pressure Sensor voltage.
Is the A/C Pressure Sensor voltage below 0.2 volt?All
Ye s®Go To 2
No®Go To 7
2 Ignition Off
Disconnect the A/C Pressure Sensor Connector.
Note: Check connectors - Clean/repair as necessary.
Ignition on with engine not running.
Using a Voltmeter, measure the 5-Volt Supply Circuit.
Is the A/C Pressure Sensor 5-volt Supply Circuit above 4.9 volts?All
Ye s®Go To 3
No®Repair the open 5-Volt Supply Circuit.
Perform Powertrain Verification Test VER-2A.
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TEST ACTION APPLICABILITY
3 Ignition Off
Disconnect the A/C Pressure Sensor Connector.
Note: Check connectors - Clean/repair as necessary.
Ignition on with engine not running.
With the DRB , read the A/C Pressure Sensor voltage.
Is the A/C Pressure Sensor voltage above 4.5 volts?All
Ye s®Replace the A/C Pressure Sensor.
Perform Powertrain Verification Test VER-2A.
No®Go To 4
4 Ignition Off
Disconnect the Powertrain Control Module.
Disconnect the A/C Pressure Sensor Connector.
Note: Check connectors - Clean/repair as necessary.
Using an Ohmmeter ,test the resistance between the A/C Pressure Sensor Signal
Circuit and Sensor Ground Circuit.
Is the resistance below 5.0 ohms?All
Ye s®Repair the Sensor Signal Circuit shorted to the Sensor Ground
Circuit.
Perform Powertrain Verification Test VER-2A.
No®Go To 5
5 Ignition Off
Disconnect the Powertrain Control Module.
Disconnect the A/C Pressure Sensor Connector.
Note: Check connectors - Clean/repair as necessary.
Using an Ohmmeter, measure the A/C Pressure Sensor Signal Circuit to ground.
Is the resistance below 5.0 ohms?All
Ye s®Repair the Sensor Signal Circuit for a short to ground.
Perform Powertrain Verification Test VER-2A.
No®Go To 6
6 Ignition off.
If there are no potential causes remaining, the PCM is assumed to be defective.
View repair options.All
Repair
Replace the Powertrain Control Module.
Perform Powertrain Verification Test VER-2A.
7 Ignition Off
Using the schematic as a guide, inspect the wiring and connectors.
Were any problems found?All
Ye s®Repair as necessary.
Perform Powertrain Verification Test VER-2A.
No®Go To 8
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P-1599 A/C PRESSURE SENSOR VOLTS TOO LOW ÐContinued
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