DIAGNOSIS Required Special Tools: • MB991958: Scan Tool (MUT-III Sub Assembly) MB991824: V.C.I. MB991827: USB Cable MB991911: Main Harness B

STEP 1. Using scan tool MB991958, check data list item 95: Manifold Absolute Pressure Sensor.

To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958. (1) Connect scan tool MB991958 to the data link connector. (2) Turn the ignition switch to the "ON" position. (3) Set scan tool MB991958 to the data reading mode for item 32, Manifold Absolute 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, 16 - 36 kPa (4.7 - 10.6 in.Hg). • When the engine is suddenly revved, manifold absolute pressure increases. (5) Turn the ignition switch to the "LOCK" (OFF) position. Q: Is the sensor operating properly? YES: 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 . NO: Go to Step 2.

STEP 2. Measure the sensor supply voltage at manifold absolute pressure sensor connector B-119 by backprobing.

(1) Do not disconnect the connector B-119. (2) Turn the ignition switch to the "ON" position.

(3) Measure the voltage between terminal No. 3 and ground by backprobing. • Voltage should be between 4.8 and 5.2 volts. (4) Turn the ignition switch to the "LOCK" (OFF) position. Q: Is the measured voltage between 4.8 and 5.2 volts? YES: Go to Step 6. NO: Go to Step 3.

STEP 3. Measure the sensor supply voltage at ECM connector C-115 <M/T> or PCM connector C-118 <A/T> by backprobing.

(1) Do not disconnect the connector C-115 <M/T> or C-118 <A/T>. (2) Turn the ignition switch to the "ON" position.

(3) Measure the voltage between terminal No. 81 <M/T> or No. 46 <A/T> and ground by backprobing. • Voltage should be between 4.8 and 5.2 volts. (4) Turn the ignition switch to the "LOCK" (OFF) position. Q: Is the measured voltage between 4.8 and 5.2 volts? YES: Go to Step 4. NO: Go to Step 5.

STEP 4. Check harness connector B-119 at the manifold absolute pressure sensor and harness connector C-115 at ECM <M/T> or C-118 at PCM <A/T> for damage.

Q: Is the harness connector in good condition? YES: Repair harness wire between manifold absolute pressure sensor connector B-119 (terminal No. 3) and ECM connector C115 (terminal No. 81) <M/T> or PCM connector C-118 (terminal No. 46) <A/T> because of open circuit or harness damage. Then go to Step 12. NO: Repair or replace it. Refer to GROUP 00E, Harness Connector Inspection . Then go to Step 12.

STEP 5. Check harness connector B-119 at the manifold absolute pressure sensor and harness connector C-115 at ECM <M/T> or C-118 at PCM <A/T> for damage.

Q: Is the harness connector in good condition? YES: Replace the ECM or PCM. Then go to STEP 12. NO: Repair or replace it. Refer to GROUP 00E, Harness Connector Inspection . Then go to Step 12.

STEP 6. Measure the ground voltage at manifold absolute pressure sensor connector B-119 by backprobing.

(1) Do not disconnect the connector B-119. (2) Turn the ignition switch to the "ON" position.

(3) Measure the voltage between terminal No. 2 and ground by backprobing. • Voltage should be 0.5 volt or less. (4) Turn the ignition switch to the "LOCK" (OFF) position. Q: Is the measured voltage 0.5 volt or less? YES: Go to Step 9. NO: Go to Step 7.

STEP 7. Check harness connector B-119 at the manifold absolute pressure sensor and harness connector C-115 at ECM <M/T> or C-118 at PCM <A/T> for damage.

Q: Is the harness connector in good condition? YES: Go to Step 8. NO: Repair or replace it. Refer to GROUP 00E, Harness Connector Inspection . Then go to Step 12.

STEP 8. Check for harness damage between manifold absolute pressure sensor connector B-119 (terminal No. 2) and ECM connector C-115 (terminal No. 92) <M/T> or PCM connector C-118 (terminal No. 57) <A/T>.

Q: Is the harness wire in good condition? YES: Replace the ECM or PCM. Then go to Step 12. NO: Repair it. Then go to Step 12.

STEP 9. Check harness connector B-119 at manifold absolute pressure sensor for damage.

Q: Is the harness connector in good condition? YES: Go to Step 10. NO: Repair or replace it. Refer to GROUP 00E, Harness Connector Inspection . Then go to Step 12.

STEP 10. Check harness connector C-115 at ECM <M/T> or C-116 at PCM <A/T> for damage.

Q: Is the harness connector in good condition? YES: Go to Step 11. NO: Repair or replace it. Refer to GROUP 00E, Harness Connector Inspection . Then go to Step 12.

STEP 11. Check for short circuit to ground and harness damage between manifold absolute pressure sensor connector B-119 (terminal No. 1) and ECM connector C-115 (terminal No. 73) <M/T> or PCM connector C-116 (terminal No. 91) <A/T>.

Q: Is the harness wire in good condition? YES: Replace the manifold absolute pressure sensor. Then go to Step 12. NO: Repair it. Then go to Step 12.