Dodge Ram Truck 1500-2500-3500. Manual — part 1150

P0108–MAP SENSOR VOLTAGE TOO HIGH (CONTINUED)

For the Engine circuit diagram (Refer to 9 - ENGINE - SCHEMATICS AND DIAGRAMS).

For a complete wiring diagram Refer to Section 8W.

•

When Monitored:
With the engine RPM above 400, the TPS voltage less than 1.13 volts, and battery voltage greater than 10.4
volts

•

Set Condition:
With the engine RPM above 400, the TPS voltage less than 1.13 volts, and battery voltage greater than 10.4
volts

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. (Refer to 9 - ENGINE - DIAGNOSIS

AND TESTING)

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ENGINE - ELECTRICAL DIAGNOSTICS - SRT-10

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P0108–MAP SENSOR VOLTAGE TOO HIGH (CONTINUED)

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.

3.

(K1) MAP SIGNAL CIRCUIT SHORTED TO BATTERY VOLTAGE

Turn the ignition off.

Disconnect the C1 and C2 PCM harness connectors.

Ignition on, engine not running.

Measure the voltage on the (K1) MAP Signal circuit in the MAP Sen-
sor harness connector.

Is the voltage above 0 volts?

Yes

>> Repair the short to battery voltage in the (K1) MAP Signal

circuit.

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

No

>> Go To 4

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ENGINE - ELECTRICAL DIAGNOSTICS - SRT-10

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P0108–MAP SENSOR VOLTAGE TOO HIGH (CONTINUED)

4.

(K1) MAP SIGNAL CIRCUIT OPEN

Turn the ignition off.

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 (K1) MAP Signal 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 5

No

>> Repair the open in the (K1) MAP Signal circuit.

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

5.

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

Measure the resistance between the (K1) MAP Signal circuit and the
(F856) 5-volt Supply circuit in the MAP Sensor harness connector.

Is the resistance below 100 ohms?

Yes

>> Repair the short between the (F856) 5-volt Supply circuit

and the (K1) MAP Signal circuit.

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

No

>> Go To 6

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ENGINE - ELECTRICAL DIAGNOSTICS - SRT-10

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P0108–MAP SENSOR VOLTAGE TOO HIGH (CONTINUED)

6.

(K900) SENSOR GROUND CIRCUIT OPEN

Measure the resistance of the (K900) Sensor ground 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 (K900) Sensor ground circuit.

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

7.

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)

DR/DH

ENGINE - ELECTRICAL DIAGNOSTICS - SRT-10

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