P0237

P0237-MAP SENSOR VOLTAGE TOO LOW





For complete wiring diagrams refer to Diagrams/Electrical.


- When Monitored:

With the ignition on and battery voltage greater than 10.4 volts.

- Set Condition:

The circuit voltage to the ECM falls below a calibrated threshold for a certain period of time.







Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.

Diagnostic Test


1. OTHER DTCS

Turn the ignition on.

With the scan tool, read the Engine DTC's.

Is there a 5-volt Supply DTC set?

Yes

- Refer to symptom list for problems related to the 5-volt Supply DTC.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

No

- Go To 2

2. HIGH VOLTAGE





Turn the ignition off.

Disconnect the Map sensor harness connector.

Check connectors - Clean/repair as necessary.

Turn the ignition on.

Measure the voltage between the (F855) 5-volt supply circuit and sensor (K916) return circuit of the Map sensor harness connector.

Is the voltage between 4.5 and 5.5 volts?

Yes

- Go To 3

No

- Go To 4

3. MAP SENSOR





While monitoring the scan tool, jumper the (F855) 5-volt supply circuit to the (K37) Map Signal circuit in the Map sensor harness connector.

Did the P0238-MAP SENSOR VOLTAGE TOO HIGH, DTC set?

Yes

- Replace the MAP sensor.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

No

- Go To 4

4. (K37) MAP SIGNAL CIRCUIT SHORTED TO (K916) SENSOR RETURN CIRCUIT





Turn the ignition off.

Disconnect the ECM harness 60 pin connector.


NOTE: Check connectors - Clean/repair as necessary.

Measure the resistance between the (K37) signal circuit and (K916) sensor return circuit in the MAP sensor harness connector.

Is the resistance greater than 100 K Ohms?

No

- Repair (K37) MAP Signal circuit shorted to (K916) sensor return circuit or replace harness.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

Yes

- Go To 5

5. (F855) 5-VOLT SUPPLY CIRCUIT SHORTED TO (K916) SENSOR RETURN CIRCUIT





Measure the resistance between the (F855) 5-volt supply circuit and (K916) Sensor Return circuit in the MAP sensor harness connector.

Is the resistance greater than 100 K Ohms?

No

- Repair (F855) 5-volt supply circuit shorted to (K916) Sensor Return circuit or replace harness.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

Yes

- Go To 6

6. (K37) MAP SIGNAL CIRCUIT OPEN





Measure the resistance of the (K37) MAP Signal circuit from the Map sensor harness connector to the ECM harness connector.

Is the resistance less than 10 Ohms?

Yes

- Go To 7

No

- Repair or replace the engine harness.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

7. (F855) 5-VOLT SUPPLY CIRCUIT OPEN





Measure the resistance of the (F855) 5-volt supply circuit from the Map sensor harness connector to the ECM harness connector.

Is the resistance less than 10 Ohms?

Yes

- Go To 8

No

- Repair or replace the engine harness.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

8. (K37) MAP SIGNAL CIRCUIT SHORTED TO GROUND





Measure the resistance between the (K37) MAP Signal circuit and the Battery negative terminal.

Is the resistance above 100k ohms?

Yes

- Go To9

No

- Repair the (K37) MAP Signal circuit for a short to ground.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

9. (F855) 5-VOLT SUPPLY CIRCUIT SHORTED TO (K916) RETURN CIRCUIT OR GROUND





Measure the resistance between the (F855) 5-volt Supply circuit in the sensor harness connector and battery negative.

Is the resistance above 100k ohms?

Yes

- Go To 10

No

- Repair the short to ground in the (F855) 5-volt Supply circuit.

10. ECM





Reconnect the ECM harness 60 pin connector.

While monitoring the scan tool, jumper the (F855) 5-volt supply circuit to the (K37) signal circuit in the MAP Sensor harness connector.

Did the P0238-MAP SENSOR VOLTAGE TOO HIGH, DTC set?

Yes

- Test Complete.

No

- Replace and program the ECM.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test