P0238
P0238-MAP SENSOR VOLTAGE TOO HIGHP0238 - Map Sensor Voltage Too High:
WHEN MONITORED
With the ignition on and battery voltage greater than 10.4 volts.
SET CONDITION
The circuit voltage to the ECM is above a calibrated threshold for a certain period of time.
POSSIBLE CAUSES
- Other DTC's
- (K37) Signal circuit shorted to battery
- (F855) 5-Volt supply circuit shorted to battery
- MAP sensor
- (K37) Signal circuit short to supply
- (F855) 5-Volt supply circuit short to battery
- Intermittent
- ECM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.
Diagnostic Test
1. OTHER DTC'S
Turn the ignition on.
With the scan tool, read the Engine DTC's.
Q: Is there a 5-volt Supply DTC set?
YES: Refer to symptom list for problems related to the 5-volt Supply DTC. Perform the POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Powertrain Verification Test - Ver 1
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 (K916) sensor return circuit of the Map sensor harness connector.
Q: Is the voltage between 4.5 and 5.5 volts?
YES: Go To 3
NO: Go To 4
3. MAP SENSOR
While monitoring scan tool, use a jumper wire to connect the (K916) return circuit with the (K37) signal circuit at the sensor connector.
Q: Did the P0237-MAP SENSOR VOLTAGE TOO LOW, DTC set?
YES: Go To 4
NO: Replace the MAP sensor. Perform the POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Powertrain Verification Test - Ver 1
4. (K37) SIGNAL CIRCUIT SHORTED TO BATTERY
Disconnect the ECM harness connectors.
Check connectors - Clean/repair as necessary.
Measure the voltage between the (K37) signal circuit at the MAP sensor harness connector and Battery Negative.
Q: Is the voltage greater than 1 volt?
YES: Repair (K37) signal circuit shorted to Battery or replace harness. Perform the POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Powertrain Verification Test - Ver 1
NO: Go To 5
5. (F855) 5-VOLT SUPPLY CIRCUIT SHORTED TO BATTERY
Measure the voltage between the (F855) 5-volt supply circuit at the MAP sensor harness connector and Battery negative.
Q: Is the voltage greater than 1 volt?
YES: Repair (F855) 5-volt supply circuit shorted to Battery or replace harness. Perform the POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Powertrain Verification Test - Ver 1
NO: Go To 6
6. (K37) SIGNAL CIRCUIT SHORT TO 5-VOLT SUPPLY
Turn the ignition off.
Disconnect the ECM harness connectors.
Measure the resistance between the (K37) signal circuit of the sensor harness connector and the (F855) 5-volt supply circuit of the sensor harness connector.
Q: Is the resistance less than 10 Ohms?
NO: Go To 7
YES: Repair or replace the engine harness. Perform the POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Powertrain Verification Test - Ver 1
7. (F855) SENSOR RETURN CIRCUIT OPEN
Measure the resistance between the (K916) sensor return circuit in the Map sensor harness connector with the (K916) sensor return circuit in the ECM harness connector.
Q: Is the resistance less than 10 Ohms?
YES: Go To 8
NO: Repair or replace the engine harness. Perform the POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Powertrain Verification Test - Ver 1
8. INTERMITTENT CONDITION
Reconnect the ECM harness connector.
Turn the ignition on.
While monitoring scan tool, connect a jumper wire between the (K37) signal circuit of the sensor harness connector and the (K916) return circuit of the sensor harness connector.
Q: Does the scan tool show P0237-Map Sensor Voltage Too Low DTC?
YES: Refer to the INTERMITTENT CONDITION Symptom (Diagnostic Procedure).
NO: Replace and program the ECM in accordance with the Service Information. Perform the POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Powertrain Verification Test - Ver 1