Chrysler 300/300 Touring/300C, Dodge Magnum. Manual — part 1008

6.

(F856) 5-VOLT SUPPLY CIRCUIT OPEN

Turn the ignition off.

Disconnect the PCM harness connectors.

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?

Yes

>> Go To 7

No

>> Repair the open in the (F856) 5-volt Supply circuit.

Perform the POWERTRAIN VERIFICATION TEST. (Refer
to 9 - ENGINE - STANDARD PROCEDURE)

7.

(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 below 100 ohms?

Yes

>> Repair the short to ground in the (F856) 5-volt Supply cir-

cuit.

Perform the POWERTRAIN VERIFICATION TEST. (Refer
to 9 - ENGINE - STANDARD PROCEDURE)

No

>> Go To 8

9 - 56

ENGINE ELECTRICAL DIAGNOSTICS

LX

8.

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?

Yes

>> 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)

LX

ENGINE ELECTRICAL DIAGNOSTICS

9 - 57

P0108-MANIFOLD ABSOLUTE PRESSURE SENSOR CIRCUIT HIGH

For a complete wiring diagram Refer to Section 8W.

9 - 58

ENGINE ELECTRICAL DIAGNOSTICS

LX

•

When Monitored:
Engine speed between 600 to 3500 RPM. Battery voltage greater than 10.37 volts.

•

Set Condition:
The MAP sensor signal voltage is greater than 4.92 volts for 3.0 seconds. One trip fault. Three good trips to
turn off the MIL. (ETC light will flash).

Possible Causes

(K1) MAP SIGNAL CIRCUIT SHORTED TO BATTERY VOLTAGE

(K1) MAP SIGNAL CIRCUIT OPEN

(K1) MAP SIGNAL CIRCUIT SHORTED TO THE (F856) 5-VOLT SUPPLY CIRCUIT

(K900) SENSOR GROUND CIRCUIT OPEN

MAP SENSOR

PCM

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING).

Diagnostic Test

1.

MAP SENSOR VOLTAGE ABOVE 4.92 VOLTS

Start the engine.

With a scan tool, read the MAP Sensor voltage.

Is the voltage above 4.92 volts?

Yes

>> Go To 2

No

>> Refer to the INTERMITTENT CONDITION Diagnostic Procedure.

Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

2.

MAP SENSOR

Turn the ignition off.

Disconnect the MAP Sensor harness connector.

Connect a jumper wire between the (K1) MAP Signal circuit and the
(K900) Sensor ground circuit in the Sensor harness connector.

Ignition on, engine not running.

With a scan tool, monitor the MAP Sensor voltage.

Is the voltage below 1.0 volt with the jumper wire installed?

Yes

>> Replace the MAP Sensor.

Perform the POWERTRAIN VERIFICATION TEST. (Refer
to 9 - ENGINE - STANDARD PROCEDURE)

No

>> Go To 3

NOTE: Remove the jumper wire before continuing.

LX

ENGINE ELECTRICAL DIAGNOSTICS

9 - 59