Page 22 of 364

Symptom:
P-0622 GENERATOR FIELD NOT SWITCHING PROPERLY
When Monitored and Set Condition:
P-0622 GENERATOR FIELD NOT SWITCHING PROPERLY
When Monitored: With the ignition key on and the engine not running.
Set Condition: This trouble code sets when the PCM tries to regulate the generator field
with no result during monitoring.
POSSIBLE CAUSES
GENERATOR FIELD RESISTANCE > = 5.0 OHMS
ASD WIRING HARNESS INTERMITTENT DEFECT
ASD WIRING HARNESS OBSERVABLE DEFECT
GENERATOR FIELD DRIVE CIRCUIT SHORT TO GROUND
GENERATOR FIELD DRIVER CIRCUIT OPEN
PCM DEFECTIVE (GENERATOR)
ASD RELAY OUTPUT CIRCUIT OPEN
TEST ACTION APPLICABILITY
1 Ignition On, Engine Not Running.
With the DRB, actuate the Generator Field Driver Circuit.
Backprobe the ASD Relay Output Circuit at the back of the Generator.
Is the voltage above 10.0 volts?All
Ye s®Go To 2
No®Repair the open ASD Relay Output Circuit, Generator to Harness
Splice.
2 Engine Running
With the DRB, actuate the Generator Field Driver Circuit.
Backprobe the Generator Field Driver Circuit at the back of the Generator.
Does the voltage shift from low to high?All
Ye s®Go To 3
No®Go To 5
3 Ignition On, Engine Not Running.
With the DRB, actuate the Generator Field Driver Circuit.
With the DRB, read codes.
Wiggle Wiring Harness from the Generator to PCM.
Does the Generator Field Driver Circuit code return?All
Ye s®Repair as necessary where wiggling caused problem to appear.
Perform Powertrain Verification Test VER-3A.
No®Go To 4
16
CHARGING
ProCarManuals.com
Page 28 of 364

TEST ACTION APPLICABILITY
3 Ignition Off
Note: Battery must be fully charged.
Note: Generator Belt tension and condition must be checked before con-
tinuing.
Disconnect the Generator Field Connector.
Disconnect PCM connector.
Note: Check connectors - Clean/repair as necessary.
Using an Ohmmeter, measure the resistance of the ASD Output Circuit from PCM
Connector to Field Connector.
Is the resistance below 5.0 ohms?All
Ye s®Go To 4
No®Repair the ASD Relay Output Circuit, open circuit.
Perform Powertrain Verification Test VER-3A.
4 Ignition Off
Note: Battery must be fully charged.
Note: Generator belt tension and condition must be checked before continu-
ing.
Disconnect the Generator Field Connector.
Disconnect the PCM Connector.
Note: Check connectors - Clean/repair as necessary.
Using an Ohmmeter, measure the resistance of the Generator Field Driver Circuit
from PCM Connector to Generator Field Connector.
Is the resistance below 5.0 ohms?All
Ye s®Go To 5
No®Repair the open Driver Circuit.
Perform Powertrain Verification Test VER-3A.
5 If there are no potential causes remaining, the Generator is assumed to be defective.
View repair options.All
Repair
Repair or replace the Generator as necessary.
Perform Powertrain Verification Test VER-3A.
6 Ignition Off
Note: Battery must be fully charged.
Note: Generator Belt tension and condition must be checked before con-
tinuing.
Disconnect the Generator Field Connector.
Disconnect the PCM Connector.
Note: Check connectors - Clean/repair as necessary.
Using an Ohmmeter, measure the resistance of the ASD Output Circuit from PCM
Connector to Field Connector.
Is the resistance below 5.0 ohms?All
Ye s®Go To 7
No®Repair the ASD Relay Output Circuit, open circuit.
Perform Powertrain Verification Test VER-3A.
22
CHARGING
P-1682 CHARGING SYSTEM VOLTAGE TOO LOW ÐContinued
ProCarManuals.com
Page 29 of 364
TEST ACTION APPLICABILITY
7 Ignition Off
Note: Battery must be fully charged.
Note: Generator belt tension and condition must be checked before continu-
ing.
Disconnect the Generator Field Connector.
Disconnect the PCM Connector.
Note: Check connectors - Clean/repair as necessary.
Using an Ohmmeter, measure the resistance of the Generator Field Driver Circuit
from PCM Connector to Generator Field Connector.
Is the resistance below 5.0 ohms?All
Ye s®Go To 8
No®Repair the open Driver Circuit.
Perform Powertrain Verification Test VER-3A.
8 If there are no potential causes remaining, the Generator is assumed to be defective.
View repair options.All
Repair
Repair or replace the Generator as necessary.
Perform Powertrain Verification Test VER-3A.
23
CHARGING
P-1682 CHARGING SYSTEM VOLTAGE TOO LOW ÐContinued
ProCarManuals.com
Page 30 of 364

Symptom:
* CHECKING CHARGING SYSTEM OPERATION WITH NO DTC'S
POSSIBLE CAUSES
TROUBLE CODES PRESENT
VOLTAGE DIFFERENCE >= 1 VOLT
GENERATOR FIELD TERMINAL INTERMITTENT DEFECTIVE
GENERATOR GROUND CIRCUIT HIGH RESISTANCE
B+ CIRCUIT HIGH RESISTANCE (0.4 VOLT)
B+ CIRCUIT HIGH RESISTANCE (1 VOLT)
PCM DEFECTIVE (CHARGING SYSTEM NO CODE)
GENERATOR BELT VISIBLY DEFECTIVE
TROUBLE CODES PRESENT 1600 RPM
TEST ACTION APPLICABILITY
1Note: Battery condition must be verified prior to this test.
Inspect the Generator Belt tension and condition.
Is the Generator Belt in good condition?All
Ye s®Go To 2
No®Repair as necessary.
Perform Powertrain Verification Test VER-3A.
2 Engine Running
With the DRB, set engine speed to 1600 RPM for 30 seconds.
With the DRB, return the engine to idle speed and read codes.
Are there any Charging System trouble codes?All
Ye s®Refer to Symptom List for problems related to Charging.
Perform Powertrain Verification Test VER-3A.
No®Go To 3
3 Turn ignition on. (Engine off)
With the DRB, actuate the Generator field.
Using a Voltmeter, backprobe Generator Field Driver Terminal at the back of
Generator.
Note: The voltage should cycle from 7.2 volts to Battery voltage every 1.4
seconds, at both Terminals.
While monitoring the Voltmeter, wiggle the field Terminals back to the PCM and ASD
Relay.
Was there any interruption in the normal cycle between 7.2 volts and Battery
voltage?All
Ye s®Repair the Wire where wiggling interrupted the voltage cycle.
Perform Powertrain Verification Test VER-3A.
No®Go To 4
24
CHARGING
ProCarManuals.com
Page 33 of 364

Symptom:
P-0106 BAROMETRIC PRESSURE OUT OF RANGE
When Monitored and Set Condition:
P-0106 BAROMETRIC PRESSURE OUT OF RANGE
When Monitored: With the ignition key on at less than 350 milliseconds and engine speed
at less than 255 RPM.
Set Condition: The PCM senses the voltage from the MAP sensor to be less than 2.196
volts but above 0.019 volt for 300 milliseconds
POSSIBLE CAUSES
MAP SENSOR 5V SUPPLY CIRCUIT OPEN
MAP SENSOR 5V SUPPLY CIRCUIT SHORT TO GROUND
MAP SENSOR SIGNAL CIRCUIT OPEN
MAP SENSOR SIGNAL CIRCUIT PARTIAL SHORT TO GROUND
MAP SENSOR WIRING HARNESS INTERMITTENT DEFECT
MAP SENSOR WIRING HARNESS OBSERVABLE DEFECT
MAP SENSOR DEFECTIVE
PCM DEFECTIVE (VOLTAGE HIGH)
PCM DEFECTIVE (VOLTAGE LOW)
TEST ACTION APPLICABILITY
1 Ignition On, Engine Not Running
With the DRB, read the MAP Sensor voltage.
Is the voltage below 2.2 volts?All
Ye s®Go To 2
No®Go To 11
2 Ignition Off
Disconnect the MAP Sensor Electrical Connector.
Turn the ignition on, engine not running.
Note: Check connectors - Clean/repair as necessary.
Using a Voltmeter, measure voltage of the 5-Volt Supply Circuit at the Map Sensor
Connector.
Is the voltage above 4.5 volts?All
Ye s®Go To 3
No®Go To 7
27
DRIVEABILITY
ProCarManuals.com
Page 36 of 364

Symptom:
P-0107 MAP SENSOR VOLTAGE TOO LOW
When Monitored and Set Condition:
P-0107 MAP SENSOR VOLTAGE TOO LOW
When Monitored: With engine rpm above 400 but less than 1500 and the TP Sensor
voltage less than 1.0 volt.
Set Condition: The MAP Sensor Signal voltage is below 1.2 volts at start, or below .02 volt
for 1.76 seconds with engine running.
POSSIBLE CAUSES
MAP SENSOR CONN/WIRING HARNESS INTERMITTENT DEF
MAP SENSOR CONN/WIRING HARNESS OBSERVABLE DEFECT
MAP SENSOR SIGNAL CIRCUIT SHORTED TO GROUND
MANIFOLD ABSOLUTE PRESSURE SENSOR DEFECTIVE
POWERTRAIN CONTROL MODULE DEFECTIVE
MAP SENSOR SIGNAL CIRCUIT OPEN
MAP SENSOR SIGNAL CKT SHORTED TO SENSOR GROUND CKT
TEST ACTION APPLICABILITY
1 Ignition On, Engine Not Running
With the DRB, read the MAP Sensor voltage.
Is the MAP Sensor voltage below 1.2 volts?All
Ye s®Go To 2
No®Go To 6
2 Ignition Off
Disconnect the MAP Sensor Electrical Connector.
Ignition on, engine not running.
Note: Check connectors - Clean/repair as necessary.
Use the DRB to read MAP Sensor voltage.
Is the MAP Sensor voltage above 4.0 volts?All
Ye s®Replace the MAP Sensor.
Perform Powertrain Verification Test VER-5A.
No®Go To 3
30
DRIVEABILITY
ProCarManuals.com
Page 38 of 364

Symptom:
P-0108 MAP SENSOR VOLTAGE TOO HIGH
When Monitored and Set Condition:
P-0108 MAP SENSOR VOLTAGE TOO HIGH
When Monitored: With engine rpm above 400 but less than 1500 and closed throttle.
Set Condition: The MAP Sensor Signal voltage is greater than 4.6.
POSSIBLE CAUSES
MAP SENSOR GROUND CIRCUIT OPEN
MAP SENSOR SIGNAL CIRCUIT OPEN
MAP SENSOR DEFECTIVE
MAP SENSOR WIRING HARN AND CONN INTERMITTENT DEF
MAP SENSOR WIRING HARNESS AND CONN OBSERVABLE DEF
PCM DEFECTIVE (MAP SENSOR VOLTAGE TOO HIGH)
TEST ACTION APPLICABILITY
1 Start the engine.
With the DRB, read the MAP Sensor voltage.
Is the MAP Sensor voltage above 4.6 volts?All
Ye s®Go To 2
No®Go To 6
2 Ignition Off
Disconnect the MAP Sensor Electrical Connector.
Note: Check connectors - Clean/repair as necessary.
Connect a jumper wire between the Sensor Signal and Sensor Ground Circuits.
Turn ignition on, use the DRB to read the MAP Sensor voltage.
Is the voltage below 1.0 volt?All
Ye s®Replace the MAP Sensor.
Perform Powertrain Verification Test VER-5A.
No®Go To 3
3 Ignition Off
Disconnect the MAP Sensor Electrical Connector.
Note: Check connectors - Clean/repair as necessary.
Connect a jumper wire between the Sensor Signal Circuit and an engine ground.
Ignition On.
Read the MAP Sensor voltage.
Is the MAP Sensor voltage below 1.0 volt?All
Ye s®Repair the open MAP Sensor Ground Circuit.
Perform Powertrain Verification Test VER-5A.
No®Go To 4
32
DRIVEABILITY
ProCarManuals.com
Page 40 of 364

Symptom:
P-0112 INTAKE AIR TEMP SENSOR VOLTAGE LOW
When Monitored and Set Condition:
P-0112 INTAKE AIR TEMP SENSOR VOLTAGE LOW
When Monitored: With the ignition on and the engine running.
Set Condition: The intake air sensor circuit voltage at PCM cavity 37 goes below .51 volt.
POSSIBLE CAUSES
IAT SEN WIRING HARNESS INTERMITTENT DEFECT
IAT SEN WRING HARNESS OBSERVABLE DEFECT
SENSOR SIGNAL CIRCUIT SHORT TO GROUND
SENSOR SIGNAL CIRCUIT SHORT TO SENSOR GND CIRCUIT
IAT SENSOR VOLTAGE GREATER THAN 4.0 VOLTS
PCM DEFECTIVE (IAT SENSOR)
TEST ACTION APPLICABILITY
1 Ignition On, Engine Not Running
With the DRB, read the IAT Sensor voltage.
Is the IAT Sensor voltage below 0.5 volt?All
Ye s®Go To 2
No®Go To 6
2 Ignition Off
Disconnect the IAT Sensor Connector.
Note: Check connectors - Clean/repair as necessary.
Ignition On, Engine Not Running
With the DRB, read the IAT Sensor voltage.
Is the IAT Sensor voltage above 4.0 volts?All
Ye s®Replace the IAT Sensor.
Perform Powertrain Verification Test VER-5A.
No®Go To 3
3 Ignition Off
Disconnect the IAT Sensor Connector.
Note: Check connectors - Clean/repair as necessary.
Disconnect the PCM Connector.
Check connectors - Clean/repair as necessary.
Using an ohmmeter, measure the 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-5A.
No®Go To 4
34
DRIVEABILITY
ProCarManuals.com