MAP Sensor Error Codes

Mopar Icon Mopar's Notes
This cleaning procedure will not correct any error codes that are being produced by the MAP sensor (P0237 or P0238). If you got a fueling enhancement box of any type hooked to the MAP sensor lines it could be a internal fault of the boost fooler circuit causing the MAP sensor error code. If the truck is stock then the MAP sensor requires replacement.

DTC P0236: MAP SENSOR TOO HIGH TOO LONG

Description
Information for when Manifold Air Pressure (MAP) sensor is monitored and conditions required for DTC to be stored are not available from manufacturer. Possible causes are: improper boost pressure, DTC for MAP sensor voltage too high or too low exists, DTC for auxiliary 5-volt output exists, defective MAP sensor, defective Engine Control Module (ECM), or defective connectors or wiring.

Testing
1. Turn ignition on with engine off. Using scan tool, check for DTCs. If DTC P0237, P0238 or P1475 exists, perform DTC P0237: MAP SENSOR VOLTAGE TOO LOW , DTC P0238: MAP SENSOR VOLTAGE TOO HIGH , or DTC P1475: AUXILIARY 5 VOLT OUTPUT TOO HIGH test as required. If none of DTCs listed exist, go to next step.

2. Turn ignition off. Perform turbocharger boost pressure test.
If boost pressure is not within specification, repair as necessary. If boost pressure is within specification, go to next step.

3. Ensure ignition is off. Disconnect MAP sensor connector. MAP sensor is located on driver's side rear corner of cylinder head. Turn ignition on with engine off. Using DVOM, measure voltage between engine ground and terminal "A" (Orange wire) on MAP sensor connector.  If voltage is 4.75-5.25 volts, go to next step. If voltage is not 4.75-5.25 volts, repair Orange wire between MAP sensor and ECM. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector.

4. Ensure MAP sensor connector is still disconnected and ignition is on with engine off. Using DVOM, measure voltage between terminals "A" (Orange wire) and "B" (Black/Light Blue wire) on MAP sensor connector. If voltage is 4.75-5.25 volts, go to next step. If voltage is not 4.75-5.25 volts, repair open in Black/Light Blue wire between MAP sensor and ECM.

5. Ensure MAP sensor connector is still disconnected and ignition is on with engine off. Using scan tool, read MAP sensor voltage. If MAP sensor voltage is .42-.58 volt, go to next step. If MAP sensor voltage is not .42-.58 volt, replace MAP sensor.

6. Turn ignition off. Ensure MAP sensor connector is still disconnected. Disconnect ECM connector. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. Using DVOM, measure resistance between terminal "C" (Gray/Red wire) on MAP sensor connector and terminal No. 8 (Gray/Red wire) on ECM connector.  If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in Gray/Red wire between MAP sensor and ECM.

7. Using DVOM, measure resistance between ground and terminal "C" (Gray/Red wire) on MAP sensor connector. If resistance is 5 ohms or more, go to next step. If resistance is less than 5 ohms, repair short to ground in Gray/Red wire between MAP sensor and ECM.

8. Using DVOM, measure resistance between terminals "B" (Black/Light Blue wire) and "C" (Gray/Red wire) on MAP sensor connector. If resistance is 5 ohms or more, go to next step. If resistance is less than 5 ohms, repair Black/Light Blue wire and Gray/Red wire between ECM and MAP sensor as they are shorted together.

9. Using DVOM, measure resistance between terminals "A" (Orange wire) and "C" (Gray/Red wire) on MAP sensor connector. If resistance is 5 ohms or more, replace ECM. If resistance less than 5 ohms, repair Orange wire and Gray/Red wire between ECM and MAP sensor as they are shorted together

DTC P0237: MAP SENSOR VOLTAGE TOO LOW

Description
Manifold Air Pressure (MAP) sensor voltage is monitored when engine speed is more than 416 RPM but less than 3520 RPM and battery voltage is more than 10.4 volts. DTC may be stored if Engine Control Module (ECM) senses MAP sensor signal voltage is less than .1 volt for 2 seconds with engine running. Possible causes are: improper boost pressure, DTC for auxiliary 5-volt output exists, defective MAP sensor, defective ECM, or defective connectors or wiring.

Testing
1. Turn ignition on with engine off. Using scan tool, check for DTCs. If DTC P1488 does not exist, go to next step. If DTC P1488 exists, perform DTC P1488: AUXILIARY 5 VOLT OUTPUT TOO LOW test.

2. Start engine and allow engine to idle. Using scan tool, read MAP sensor voltage. If MAP sensor voltage is .2 volt or more, go to next step. If MAP sensor voltage is less than .2 volt, go to step 4 .

3. Shut engine off. Turn ignition on with engine off. Using scan tool, read MAP sensor voltage. If MAP sensor voltage is less than 2.35 volts, go to next step. If MAP sensor voltage is 2.35 volts or more, go to step 9 .

4. Turn ignition off. Perform turbocharger boost pressure test. If boost pressure is not within specification, repair as necessary. If boost pressure is within specification, go to next step.

5. Ensure ignition is off. Disconnect MAP sensor connector. MAP sensor is located on driver's side rear corner of cylinder head.  Turn ignition on with engine off. Using DVOM, measure voltage at terminal "A" (Orange wire) on MAP sensor connector. If voltage is more than 4.5 volts, go to next step. If voltage is 4.5 volts or less, repair open in Orange wire between ECM and MAP sensor. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector.

6. Turn ignition off. Ensure MAP sensor connector is still disconnected. Disconnect ECM connector. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. Using DVOM, measure resistance between ground and terminal "C" (Gray/Red wire) on MAP sensor connector. If resistance is 5 ohms or more, go to next step. If resistance is less than 5 ohms, repair short to ground in Gray/Red wire between MAP sensor and ECM.

7. Ensure ignition is off. Reinstall ECM electrical connector. Ensure MAP sensor connector is still disconnected. Turn ignition on with engine off. Using scan tool, read MAP sensor voltage. If MAP sensor voltage is 4.5 volts or less, go to next step. If MAP sensor voltage is more than 4.5 volts, replace MAP sensor.

8. Turn ignition off. Disconnect ECM connector. Using DVOM, measure resistance between terminals "B" (Black/Light Blue wire) and "C" (Gray/Red wire) on MAP sensor connector. If resistance is 5 ohms or more, replace ECM. If resistance is less than 5 ohms, repair Black/Light Blue wire and Gray/Red wire between ECM and MAP sensor as they are shorted together.

9. Ensure ignition is on with engine off. Using scan tool, read MAP sensor voltage while wiggling wiring harness and connectors between MAP sensor and ECM. MAP sensor is located on driver's side rear corner of cylinder head.  ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector.  If MAP sensor voltage does not change while wiggling wiring harness and connectors, go to next step. If MAP sensor voltage changes while wiggling wiring harness and connectors, repair wiring or connectors as necessary.

10. Turn ignition off. Inspect wiring and connectors between MAP sensor and ECM. If no problems exist, go to next step. If any problems exist, repair wiring or connectors as necessary.

11. Turn ignition on with engine off. Using scan tool, go to FREEZE FRAME data and ensure CAUSED BY DTC hex code is the same as DTC on DTC screen. It is assumed that an intermittent problem exists with wiring or connectors. Inspect MAP sensor connector and ECM connector for miswired, corroded, pushed out or damaged terminals. Inspect MAP sensor and ECM wiring for chafed, pierced or partially broken
wires. If terminals are not miswired, corroded, pushed out or damaged and wiring is okay, check for technical service bulletins that may apply. If terminals are miswired, corroded, pushed out or damaged, or wiring is damaged, repair as necessary.

DTC P0238: MAP SENSOR VOLTAGE TOO HIGH

Description
Manifold Air Pressure (MAP) sensor voltage is monitored when engine speed is more than 416 RPM but less than 3520 RPM and battery voltage is more than 10.4 volts. DTC may be stored if Engine Control Module (ECM) senses MAP sensor signal voltage is more than 4.88 volts at start or with engine running for 2 seconds. Possible causes are: improper boost pressure, DTC exists for high voltage on intake air temperature sensor, engine coolant temperature sensor or oil pressure sensor, defective MAP sensor, defective ECM, or defective connectors or wiring.

Testing
1. Turn ignition on with engine off. Using scan tool, check for DTCs. If DTC P0113 or P0118 exists, perform DTC P0113: INTAKE AIR TEMPERATURE SENSOR VOLTAGE TOO HIGH or DTC P0118: ENGINE COOLANT TEMPERATURE SENSOR VOLTAGE TOO HIGH test. If these DTC do not exist, go to next step.

2. Ensure ignition is on with engine off. Using scan tool, check for DTCs. If no sensor supply voltage too high DTCs are set, go to next step. If DTC P0523 exist, go to DTC P0523: OIL PRESSURE VOLTAGE TOO HIGH test. If any other sensor supply voltage too high DTCs exist, perform appropriate test for specified DTC. See DIAGNOSTIC TROUBLE CODE DEFINITIONS .

3. Ensure ignition is on with engine off. Using scan tool, read MAP sensor voltage. If MAP sensor voltage is less than 5.5 volts, go to next step. If MAP sensor voltage is 5.5 volts or more, go to step 7 .

4. Ensure ignition is on with engine off. Using scan tool, read MAP sensor voltage while wiggling wiring harness and connectors between MAP sensor and ECM. MAP sensor is located on driver's side rear corner of cylinder head.  ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector.  If MAP sensor voltage does not change while wiggling wiring harness and connectors, go to next step. If MAP sensor voltage changes while wiggling wiring harness and connectors, repair wiring or connectors as necessary.

5. Turn ignition off. Conditions required to set DTC are not present at this time. Inspect wiring and connectors between MAP sensor and ECM. If no problems exist, go to next step. If any problems exist, repair wiring or connectors as necessary.

6. Turn ignition on with engine off. Using scan tool, go to FREEZE FRAME data and ensure CAUSED BY DTC hex code is the same as DTC on DTC screen. It is assumed that an intermittent problem exists with wiring or connectors. Inspect MAP sensor connector and ECM connector for miswired, corroded, pushed out or damaged terminals. Inspect MAP sensor and ECM wiring for chafed, pierced or partially broken wires. If terminals are not miswired, corroded, pushed out or damaged and wiring is okay, check for technical service bulletins that may apply. If terminals are miswired, corroded, pushed out or damaged, or wiring is damaged, repair as necessary.

7. Turn ignition off. Perform turbocharger boost pressure test.
If boost pressure is not within specification, repair as necessary. If boost pressure is within specifications, go to next step.

8. Ensure ignition is off. Disconnect MAP sensor connector. MAP sensor is located on driver's side rear corner of cylinder head. Turn ignition on with engine off. Using DVOM, measure voltage at terminal "C" (Gray/Red wire) on MAP sensor connector.  If voltage is 5.5 volts or less, go to next step. If voltage is more than 5.5 volts, repair short to voltage on Gray/Red wire between MAP sensor and ECM. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector.

9. Turn ignition off. Ensure MAP sensor connector is still disconnected. Connect jumper wire between cylinder block and terminal "C" (Gray/Red wire) on MAP sensor connector. Turn ignition on with engine off. Using scan tool, read MAP sensor voltage. If MAP sensor voltage is one volt or more, remove jumper wire and go to next step. If MAP sensor voltage is less than one volt, remove jumper wire and repair open in Black/Light Blue wire between MAP sensor and ECM.

10. Turn ignition off. Ensure MAP sensor connector is still disconnected. Disconnect ECM connector. Using DVOM, measure resistance between terminal "C" (Gray/Red wire) on MAP sensor connector and terminal No. 8 (Gray/Red wire) on ECM connector.  If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in Gray/Red wire between MAP sensor and ECM.

11. Ensure ignition is off. Reinstall ECM connector. Ensure MAP sensor connector is still disconnected. Connect jumper wire between terminals "B" (Black/Light Blue wire) and "C" (Gray/Red wire) on MAP sensor connector. Using scan tool, read MAP sensor voltage. If MAP sensor voltage is less than one volt, remove jumper wire and replace MAP sensor.  If MAP sensor voltage is one volt or more, remove jumper wire and replace ECM

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