2000 CHRYSLER VOYAGER turn signal

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
214
DRIVEABILITY
ProCarManuals.com

TEST ACTION APPLICABILITY
5 Ignition Off
Disconnect the Upstream or Downstream O2 Sensor Connector that the voltage is
below 0.10 volts.
Note: Check connectors - Clean/repair as necessary.
Disconnect the Powertrain Control Module.
Note: Check connectors - Clean/repair as necessary.
Using an Ohmmeter, measure the resistance between the O2 Sensor Signal Circuit
and a good ground.
Is the resistance below 5.0 ohms?All
Ye s®Repair the O2 Sensor Signal Circuit for a short to ground.
Perform Powertrain Verification Test VER-2A.
No®Go To 6
6 If there are no potential causes remaining, the Upstream or Downstream O2 Sensor
is assumed to be defective.
View repair options.All
Repair
Replace the Upstream or Downstream O2 Sensor that was below
0.10 volts.
Perform Powertrain Verification Test VER-2A.
7 Engine Running
Allow the Engine to idle.
Inspect the Engine for any abnormal vacuum conditions.
Are there any abnormal vacuum conditions?All
Ye s®Repair abnormal Engine Vacuum condition as required.
Perform Powertrain Verification Test VER-2A.
No®Go To 8
8 Engine Running
With the DRB, reset the Adaptive Fuel Memory.
Note: The engine must be running and at normal operating temperature.
Note: The Downstream O2 Sensor should switch slower than the Upstream
O2 Sensor.
With the DRB, read the O2 Sensor voltages for 10 seconds or more.
Are the O2 Sensor voltages switching normally?All
Ye s®Test Complete.
No®Refer to symptom * CHECKING THE ENGINE MECHANICAL
SYSTEMS in the DRIVEABILITY category.
9 Ignition Off
Install a Fuel Pressure Gauge to the Fuel Line. Use special tools if necessary.
Turn ignition on.
With the DRB, actuate the ASD Fuel System Test.
Allow Fuel Pressure to stabilize.
With the DRB, stop Fuel System Test. Monitor the Pressure Gauge for 1 minute.
Is the Fuel Pressure below 10 psi?All
Ye s®If Fuel Pump and Lines are OK, replace leaking Injector(s) as
necessary.
Perform Powertrain Verification Test VER-2A.
No®Go To 10
235
DRIVEABILITY
* CHECKING FOR OXYGEN SENSOR SWITCHING ÐContinued
ProCarManuals.com

Symptom:
* CHECKING THE A/C PRESSURE SENSOR SIGNAL
POSSIBLE CAUSES
A/C PRESSURE SENSOR 5-VOLT SUPPLY CIRCUIT OPEN
HIGH RESISTANCE IN THE A/C PRESSURE SENSOR SIGNAL CKT
TEST ACTION APPLICABILITY
1 Turn the ignition on.
Using the DRB, read the trouble codes.
Are any A/C Pressure sensor trouble codes set?All
Ye s®Go to the A/C Pressure sensor trouble code.
No®Go To 2
2 Turn the ignition off.
Disconnect the A/C Pressure Sensor harness connector.
Turn the ignition on.
Using a voltmeter, measure the A/C Pressure Sensor 5±volt supply circuit.
Is the voltage above 4.8 volts?All
Ye s®Go To 3
No®Repair the open in the A/C Pressure Sensor 5±volt supply circuit.
Perform Powertrain Verification Test VER-2A.
3 Turn the ignition on.
Using the DRB, monitor the A/C Pressure voltage.
Disconnect the A/C Pressure Sensor harness connector.
Is the voltage above 4.8 volts?All
Ye s®Test Complete.
No®Repair the high resistance in the A/C Pressure Sensor Signal
circuit.
Perform Powertrain Verification Test VER-2A.
255
DRIVEABILITY
ProCarManuals.com