P0106 Manifold Absolute Pressure/Barometric Pressure Circuit Range/Performance

OMPONENT LOCATION

GENERAL DESCRIPTION

In order to determine the correct amount of fuel, the ECM uses the MAP to help determing the amount of intake air flow. To measure the air flow in the intake manifold, the MAFS is used at idle and MAPS is required during accelerating. The MAPS(Manifold Absolute Pressure) calculates the amount of air indirectly as measuring the pressure inside of intake manifold. This system is called a Speed-Density type.

MAPS transfers analog output signal which is proportional to the change of intake manifold pressure, then, with this signal and RPM, ECM calculates the amount of intake air flow. The MAPS is mounted on the surge tank to measure the pressure inside of intake manifold, and it consists of a piezo electric element and a hybrid IC which amplifies the output signal from the element. A diaphragm with a piezo electric element is use to convert pressure into voltage. One side of the diaphragm has a chamber with a fixed (absolute) pressure while intake pressure is applied to the other side. As the intake manifold pressure changes, the diaphram moves which changes a voltage output.

DTC DESCRIPTION

If the signal output of MAP sensor is stuck under enable conditions or

If the acutal MAP value or lower than calculated(threshold) value for 2 min failure during tip in-out driving, or

If there is the signal change over 10% momently without the operation of accel pedal,

ECM determines that a fault exists and a DTC is stored.

DTC DETECTING CONDITION

Item

Detecting Condition

Possible cause

DTC Strategy

Case1

Monitor the MAP sensor’s signal

1.	Connecting condition

2.	Open or short to ground in power circuit

3.	Open or short to ground in signal circuit

4.	Faulty TPS

5.	Faulty MAPS

6.	Faulty ECM

Case2

The MAP reading is compared to expected MAP high and low limits based on engine speed & Throttle Position

Case3

This code detects a erratic signal change of the MAP

Enable Conditions

Case1

No Disabling Fault Present

Shutdown time > 20 minutes

Engine running

Case2

Engine Coolant Temperature ≥ 60°C (Fully Warmed up state)

600rpm < Engine Speed < 3000rpm

Case3

Engine running

l ΔAPS l < 5%

Engine Speed > 800rpm

Threshold value

Case1

The difference between the signal at key-on and the signal at engine start < 0.5 kPa

Case2

– Power Test

Altitude compensated MAP < Calculated min. MAP data

Altitude compensated MAP > Calculated max. MAP data

– Decelleration Test

Timing Counter > 80

Case3

MAP_stable –MAP_current| >10 %

Diagnosis Time

Case1

For 3 seconds out of 5 seconds

Case2

Continuous (within 5min.)

Case3

–

MIL On Condition

NO MIL ON(DTC only)

SPECIFICATION

Pressure(kPa)	Voltage(V)
20	0.79
46.66	1.84
101.32	4.0

DIAGNOSTIC CIRCUIT DIAGRAM

SIGNAL WAVEFORM & DATA

Fig.1) Normal data of MAPS at idle.

Fig.2) Normal waveform of MAPS & TPS with acceleration.

It is necessary that MAPS should be checked along with TPS. Because the MAP/TPS rationality diagnostic is comprised of two tests. A deceleration test is performed to provide a robust method for detection of an altitude compensated MAP value that is too high for the deceleration condition. The second test compares the altitude compensated MAP value to both high and low limits, dependent upon throttle position and engine speed. When the MAP value is out of the threshold range, the MAP/TPS system is determined to be failed.

MONITOR GDS DATA

1.	Connect GDS to Data Link Connector(DLC).

IG “ON”.

3.	Select “DTC” button, and then Press “DTC Status” to check DTC’s information from the DTCs menu.

4.	Read “DTC Status” parameter.

Is parameter displayed “Present fault”?

	▶ Go to “Terminal and Connector inspection” procedure.
	▶ Fault is intermittent caused by poor contact in the sensor’s and/or ECM’s connector or was repaired and ECM memory was not cleared. Thoroughly check connectors for looseness, poor connection, ending, corrosion, contamination, deterioration, or damage. Repair or replace as necessary and go to “Verification of Vehicle Repair” procedure.

TERMINAL AND CONNECTOR INSPECTION

1.	Many malfunctions in the electrical system are caused by poor harness and terminals. Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.

2.	Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.

Has a problem been found?

	▶ Repair as necessary and go to “Verification of Vehicle Repair” procedure .
	▶ Go to ” Power Circuit Inspection ” procedure.

POWER CIRCUIT INSPECTION

■ Check voltage

1.	IG “OFF” and Disconnect MAPS connector.

IG “ON”.

Measure voltage between power terminal of MAPS harness connector and chassis ground.

Approx. 5V

Is the measured voltage within specification ?

	▶ Go to “Signal Circuit Inspection” Procedure.
	▶ Repair open or short in harness and go to “Verification of Vehicle Repair” procedure.

■ Check short to ground in harness

IG “OFF”.

2.	Disconnect MAPS and ECM connector.

Measure the resistance between signal terminal of MAPS harness connector and ground.

Infinite

Is the measured resistance within specification ?

	▶ Go to “Check open in harness” as follows.
	▶ Repair short to ground in harness and go to “Verification of Vehicle Repair” procedure.

■ Check open in harness

1.	IG “OFF” and disconnect MAPS and ECM connector.

Measure resistance between signal terminal of MAPS harness connector and MAPS signal terminal of ECM harness connector.

Approx. below 1Ω.

Is the measured resistance within specification ?

	▶ Go to “Ground Inspection” procedure.
	▶ Repair open in harness and go to “Verification of Vehicle Repair” procedure.

GROUND CIRCUIT INSPECTION

■ Check voltage

1.	IG “OFF” and disconnect MAPS connector and then IG “ON”.

2.	Measure voltage between signal terminal of MAPS harness connector and chassis ground (Measurement “A”)

Measure voltage between signal and ground terminals of MAPS harness connector (Measurement “B”)

Voltage difference between Measurement “A” and “B” is below 200mV.

Is the measured voltage within specification ?

	▶ Go to “Component Circuit Inspection” procedure.
	▶ Repair contact resistance or open in harness

COMPONENT INSPECTION

■ Check MAPS Performance

1.	IG “OFF” and install a GDS

2.	Connect probe to MAPS and TPS to check signal waveform by using oscilloscope function.

ENG “ON” and monitor signal waveform during acceleration and deceleration.

Signal waveform will be displayed as follows.

Pressure(kPa)	Voltage(V)
20	0.79
46.66	1.84
101.32	4.0

Is the relationship between the MAP and the TPS correct?

▶ Substitute with a known – good ECM and check for proper operation. If the problem is corrected, replace ECM and go to “Verification of Vehicle Repair” procedure.

There is a memory reset function on GDS that can erase optional parts automaticallydetected and memorized by ECM. Before or after testing ECM on the vehicle, use this function to reuse the ECM on the others

▶ Substitute with a known – good MAPS and check for proper operation. If the problem is corrected, replace MAPS

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