Chrysler 300/300 Touring/300C, Dodge Magnum. Manual — part 1152

7.

(B29) BRAKE SWITCH NO.1 SIGNAL CIRCUIT OPEN

Measure the resistance of the (B29) Brake Switch No.1 Signal circuit
from the Stop Lamp Switch harness connector to the appropriate ter-
minal of special tool #8815.

Is the resistance below 5.0 ohms?

Yes

>> Go To 8

No

>> Repair the open in the (B29) Brake Switch No.1 Signal cir-

cuit.

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

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)

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ENGINE ELECTRICAL DIAGNOSTICS

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P0850-PARK/NEUTRAL SWITCH PERFORMANCE

For a complete wiring diagram Refer to Section 8W.

•

When Monitored:
Continuously with the transmission in Park, Neutral, or Drive and NOT in Limp-in mode.

•

Set Condition:
This code will set if the PCM detects an incorrect Park/Neutral switch state for a given mode of vehicle oper-
ation. One trip fault. Three good trips to turn off the MIL.

Possible Causes

TCM COMMUNICATION

PCM

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

Diagnostic Test

1.

P/N & D/R NOT IN CORRECT POSITION

NOTE: Before continuing, ensure communication can be established with the TCM. If the scan tool is unable
to communicate with the TCM or if there are related communication DTCs present refer to the Communi-
cation Category and perform the appropriate symptom.
Ignition on, engine not running.

With the scan tool, read DTCs.

Is the DTC active at this time?

Yes

>> Go To 2

No

>> Refer to the INTERMITTENT CONDITION Diagnostic Procedure.

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

2.

CHECKING TCM DTC(S)

Turn the ignition off.

With the scan tool, read TCM DTCs.

Is there any there Transmission DTC(s) present?

Yes

>> Refer to the appropriate Transmission symptom in the Transmission category.

No

>> Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal push

out. Repair as necessary. Replace and program the Powertrain Module in accordance with the Service
Information.

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

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ENGINE ELECTRICAL DIAGNOSTICS

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P1115-GENERAL TEMPERATURE RATIONALITY

For a complete wiring diagram Refer to Section 8W.

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ENGINE ELECTRICAL DIAGNOSTICS

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•

When Monitored:
Ignition on and battery voltage greater than 10 volts.

•

Set Condition:
Ambient Air, Engine Coolant, and Intake Air Temp sensor inputs are compared under cold start conditions.
After start up the temp readings are monitored. If two of the three readings agree and the third doesn’t, a DTC
is stored. Two Trip Fault. Three good trips to turn off the MIL.

Possible Causes

EXCESSIVE RESISTANCE IN THE SENSOR SIGNAL CIRCUIT

EXCESSIVE RESISTANCE IN THE (K900) SENSOR GROUND CIRCUIT

TEMPERATURE SENSOR

PCM

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

Diagnostic Test

1.

ACTIVE DTC

Ignition on, engine not running.

With a scan tool, read the DTCs.

NOTE: All ECT, Intake Air, and Ambient Air Temperature Sensor codes must be diagnosed and repaired
before continuing.

NOTE: In cold weather, this DTC could be set by a non-OEM approved block heater and no repair would be
required.

Is the DTC active at this time?

Yes

>> Go To 2

No

>> Refer to the INTERMITTENT CONDITION Diagnostic Procedure.

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

2.

TEMPERATURE SENSOR CIRCUIT

With a scan tool, read the ECT, Ambient Air Temp, and Intake Air Temp Sensor temp values.

Start the engine.

Allow the engine to reach normal operating temperature while monitoring the three Sensor temperature values.

Is the temperature for each of the Sensors increasing properly?

Yes

>> Refer to the INTERMITTENT CONDITION Diagnostic Procedure.

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

No

>> Go To 3

3.

TEMPERATURE SENSOR

Ignition on, engine not running.

Disconnect the suspected faulty sensor.

Connect a jumper wire between the Sensor Signal circuit and the (K900) Sensor ground circuit.

With the scan tool, read the voltage of the suspected Sensor.

NOTE: Remove the jumper wire before continuing.

Did the voltage reading start at 4.8 to 5.0 volts and decrease to 0 volts when the jumper wire was
installed?

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ENGINE ELECTRICAL DIAGNOSTICS

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