13A-DTC P0237: Boost Pressure Circuit Low Input

DTC P0237: Boost Pressure Circuit Low Input

CIRCUIT OPERATION

A 5-volts voltage is supplied to the boost pressure sensor power terminal from the ECM terminal UPS5. The ground terminal is grounded with ECM terminal E.
A voltage that is proportional to the intake charge pressure is sent to the ECM terminal UPS from the boost pressure sensor output terminal.

TECHNICAL DESCRIPTION

The boost pressure sensor outputs a voltage which corresponds to the intake charge pressure.
The ECM checks whether this voltage is within a specified range.

DESCRIPTIONS OF MONITOR METHODS

Boost pressure sensor output voltage is out of specified range.

MONITOR EXECUTION

Continuous

MONITOR EXECUTION CONDITIONS (Other monitor and Sensor)

Other Monitor (There is no temporary DTC set in memory for the item monitored below)

Not applicable

Sensor (The sensor below is determined to be normal)

Not applicable

DTC SET CONDITIONS

Logic Flow Chart

Check Conditions

8 minutes or more have passed since the engine starting sequence was completed.

Engine coolant temperature is more than 0°C (32°F).

Judgment Criterion

Boost pressure sensor output voltage is less than 0.2 volt for 2 seconds.

FAIL-SAFE AND BACKUP FUNCTION

Intake charge pressure is restricted.

OBD-II DRIVE CYCLE PATTERN

Refer to Diagnostic Function - OBD-II Drive Cycle - Pattern 1 .

TROUBLESHOOTING HINTS (The most likely causes for this code to be set are:)

Boost pressure sensor failed.
Open or shorted boost pressure sensor circuit, harness damage or connector damage.
ECM failed.

DIAGNOSIS

Required Special Tool:

MB991709: Test Harness

STEP 1. Using scan tool (M.U.T.-IIISE), check data list item 125: Boost Pressure Sensor.

caution

To prevent damage to scan tool (M.U.T.-IIISE), always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool (M.U.T.-IIISE).

(1) Connect scan tool (M.U.T.-IIISE). Refer to HOW TO CONNECT THE SCAN TOOL (M.U.T.-IIISE)

(2) Turn the ignition switch to the "ON" position.

(3) Set scan tool (M.U.T.-IIISE) to the data reading mode for item 125, Boost Pressure Sensor.

When altitude is 0 m (0 foot), 101 kPa (29.8 in.Hg).
When altitude is 600 m (1,969 feet), 95 kPa (28.1 in.Hg).
When altitude is 1,200 m (3,937 feet), 88 kPa (26.0 in.Hg).
When altitude is 1,800 m (5,906 feet), 81 kPa (23.9 in.Hg).

(4) Start the engine.

When the engine is idling, 70 - 110 kPa (20.7 - 32.4 in.Hg) (Near the atmospheric).
When the engine is suddenly revved, intake charge pressure varies.

(5) Turn the ignition switch to the "LOCK" (OFF) position.

Is the sensor operating properly?

It can be assumed that this malfunction is intermittent. Refer to GROUP 00, How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions

Go to Step 2

STEP 2. Measure the sensor supply voltage at boost pressure sensor connector.

(1) Disconnect the connector and measure at the harness side.

(2) Turn the ignition switch to the "ON" position.

(3) Measure the voltage between terminal UPS5 line and ground.

Voltage should be between 4.9 and 5.1 volts.

(4) Turn the ignition switch to the "LOCK" (OFF) position.

Is the measured voltage between 4.9 and 5.1 volts?

Go to Step 5

Go to Step 3

STEP 3. Check of open circuit and short circuit in UPS5 line between boost pressure sensor connector and ECM connector.

Is the harness wire in good condition?

Go to Step 4

Repair the connector(s) or wiring harness. Then go to Step 9

STEP 4. Using scan tool (M.U.T.-IIISE), check data list item 125: Boost Pressure Sensor.

(1) Turn the ignition switch to the "ON" position.

(2) Set scan tool (M.U.T.-IIISE) to the data reading mode for item 125, Boost Pressure Sensor.

When altitude is 0 m (0 foot), 101 kPa (29.8 in.Hg).
When altitude is 600 m (1,969 feet), 95 kPa (28.1 in.Hg).
When altitude is 1,200 m (3,937 feet), 88 kPa (26.0 in.Hg).
When altitude is 1,800 m (5,906 feet), 81 kPa (23.9 in.Hg).

(3) Start the engine.

When the engine is idling, 70 - 110 kPa (20.7 - 32.4 in.Hg) (Near the atmospheric).
When the engine is suddenly revved, intake charge pressure varies.

(4) Turn the ignition switch to the "LOCK" (OFF) position.

Is the sensor operating properly?

It can be assumed that this malfunction is intermittent. Refer to GROUP 00, How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions

Replace the ECM (Refer to Removal and Installation

). Then go to Step 9

STEP 5. Check of harness damage in UPS5 line between boost pressure sensor connector and ECM connector.

Is the harness wire in good condition?

Go to Step 6

Repair the connector(s) or wiring harness. Then go to Step 9

STEP 6. Measure the sensor output voltage at boost pressure sensor connector.

(1) Using test harness special tool MB991709 to connect connector, and measure at pick-up harness.

(2) Turn the ignition switch to the "ON" position.

(3) Measure the voltage between terminal UPS and ground.

When altitude is 0 m (0 foot), voltage should be between 1.4 and 1.6 volts.
When altitude is 600 m (1,969 feet), voltage should be between 1.3 and 1.5 volts.
When altitude is 1,200 m (3,937 feet), voltage should be between 1.2 and 1.4 volts.
When altitude is 1,800 m (5,906 feet), voltage should be between 1.1 and 1.3 volts.

(4) Turn the ignition switch to the "LOCK" (OFF) position.

Is the measured voltage normal?

Go to Step 8

Go to Step 7

STEP 7. Check of short circuit to ground in UPS line between boost pressure sensor connector and ECM connector.

Is the harness wire in good condition?

Replace the boost pressure sensor. Then go to Step 9

Repair the connector(s) or wiring harness. Then go to Step 9

STEP 8. Check of open circuit and harness damage in UPS line between boost pressure sensor connector and ECM connector.

Is the harness wire in good condition?

Go to Step 4

Repair the connector(s) or wiring harness. Then go to Step 9

STEP 9. Test the OBD-II drive cycle.

(1) Carry out a test drive with the drive cycle pattern. Refer to Diagnostic Function - OBD-II Drive Cycle - Pattern 1

(2) Check the diagnostic trouble code (DTC).

Is DTC P0237 set?

Retry the troubleshooting.

The inspection is complete.