Вот описалово диагностики от олдаты.
DTC P0101: MAF SYSTEM PERFORMANCE (3.5L "W" BODY & 4.8L, 5.3L & 6.0L "C" & "K" SERIES)
NOTE: For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.
Circuit Description
Mass Airflow (MAF) sensor measures amount of air entering engine during a given time. PCM uses MAF sensor information for fuel delivery calculations. MAF sensor readings during acceleration are much higher than those during deceleration or idle.
PCM calculates what MAF sensor reading should be when received from sensor under certain conditions using engine speed (RPM), throttle position, and barometric pressure parameters. When certain test conditions are met, PCM will compare its calculated MAF value to actual value received from sensor. If difference is too great, DTC P0101 will set.
For duplication of DTC, ensure:
- Other DTCs are not set.
- Engine is running with EGR duty cycle and pintle position is at less than 50 percent.
- System voltage is 9-18 volts.
- Throttle angle is less than 50 percent.
- MAP and TP sensor values are steady.
These conditions must be present for a predetermined amount of time.
Diagnostic Procedures
1. Perform On-Board Diagnostic (OBD) system check. See ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
2. If DTC P0102, P0103, P0107, P0108, P0121, P0122, P0123 or P1635 is also set, diagnose these DTCs first. If specified DTCs are not set, go to next step.
3. Turn ignition off. Remove MAP sensor from intake manifold, leaving harness connected. Connect a hand-held vacuum pump to MAP sensor. Turn ignition on, with engine off. Observe MAP sensor display on scan tool while slowly applying 20 in. Hg of vacuum to MAP sensor. Each one in. Hg of vacuum should result in a smooth 3-4 kPa decrease in MAP sensor value. If MAP sensor value changes as specified, go to next step. If MAP sensor value does not change as specified, go to step 19.
4. Apply 20 in. Hg of vacuum to MAP sensor. If MAP sensor reading on scan tool is 34 kPa or less, go to next step. If MAP sensor value is not as specified, go to step 19.
5. Disconnect vacuum source from MAP sensor. If MAP sensor reading returns to original value, go to next step. If MAP sensor does not return to original value, go to step 19.
6. Turn ignition on, with engine off. Review FREEZE FRAME and/or FAILURE RECORDS data for DTC P0101 and observe parameters. Clear DTCs. Turn ignition off for 15 seconds. Start engine and operate under conditions required to duplicate DTC, and as close to conditions recorded in FREEZE FRAME/FAILURE RECORDS as possible. See CIRCUIT DESCRIPTION. Using scan tool, check for DTCs. If DTC P0101 is set, go to next step. If DTC P0101 is not set, see DIAGNOSTIC AIDS.
7. Check for restricted MAF sensor inlet. Check for intake manifold and throttle body vacuum leaks. Check PCV system operation. Check for leaks at EGR flange and pipes. Repair as necessary. After repairs, go to step 21. If no problems are found, go to next step.
8. Turn ignition off. Disconnect MAF sensor connector. Turn ignition on, with engine off. Using DVOM, measure voltage between battery ground and signal circuit at MAF sensor harness connector. If voltage is near 5 volts, go to next step. If voltage is not as specified, go to step 10.
9. Connect a test light between ignition feed circuit and ground circuit at MAF sensor harness connector. If test light illuminates, go to step 13. If test light does not illuminate, go to step 12.
10. If voltage is less than 4.5 volts, go to step 14. If voltage is not as specified, go to next step.
11. Turn ignition off. Disconnect PCM harness connectors. Turn ignition on, with engine off. Using DVOM, measure voltage between ground and signal circuit at MAF sensor harness connector. If voltage is near zero volts, go to step 20. If voltage is not as specified, go to step 17.
12. Using a test light connected to battery ground, probe ignition feed circuit at MAF sensor harness connector. If test light illuminates, go to step 15. If test light does not illuminate, go to step 16.
13. Check for poor connections and terminal tension at MAF sensor. Repair as necessary. After repairs, go to step 21. If no problems are found, go to step 18.
14. Check MAF sensor signal circuit for an open, short to ground, or short to MAF sensor ground circuit. Repair as necessary. After repairs, go to step 21. If no problems are found, go to step 20.
15. Locate and repair open in MAF sensor ground circuit. After repairs, go to step 21.
16. Locate and repair open in MAF sensor ignition feed circuit. After repairs, go to step 21.
17. Locate and repair short to voltage in MAF sensor signal circuit. After repairs, go to step 21.
18. Replace MAF sensor. After repairs, go to step 21.
19. Replace MAP sensor. After repairs, go to step 21.
20. Replace PCM. Perform PCM reprogramming procedures. After repairs, go to step 21.
21. Using scan tool, clear DTCs. Turn ignition off for 15 seconds. Start engine and operate under conditions required to duplicate DTC. See CIRCUIT DESCRIPTION. Using scan tool, check for DTCs. If DTC P0101 is set, go to step 2. If DTC P0101 is not set, go to next step.
22. Using scan tool, review CAPTURED INFO. If any DTCs are present that have not been diagnosed, go to appropriate DTC test. If no DTCs are present, system is okay.
Diagnostic Aids
For any test that requires probing PCM or component harness connectors, use Connector Test Adapter Kit (J-35616-A). This will prevent damage to harness connector terminals.
Check for skewed or stuck TP sensor. A faulty TP sensor or TP sensor circuit can cause PCM to incorrectly calculate predicted mass airflow value.
Check for sticking throttle plate or excessive deposits on throttle plate or throttle bore, TP sensor signal circuit for short to voltage or for poor connection or high resistance in TP sensor ground circuit.
Check for poor connections at PCM or at component. Inspect harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals and poor terminal-to-wire connections.
Check for misrouted wiring harness. Inspect harness to ensure that it is not routed too close to high voltage wires (spark plug wires) or too close to high current devices (generator, motors, solenoids).
Check for damaged wiring harness. If harness appears to be okay, observe scan tool while moving related connectors and wiring harnesses. A change in scan tool display may help to locate fault. If sensor signal is only affected when harness is moved at a component, and there is no problem with wiring harness or connections, component may be faulty.
Check for plugged intake air duct or dirty air filter. A wide open throttle acceleration from a stop should cause mass airflow displayed on scan tool to increase from about 4-7 gm/s at idle to 100 gm/s or greater at the time of 1-2 shift. If increase is not as specified, check for a restriction.
Check for water entering air intake system and contaminating MAF sensor. Water rapidly cools hot wires in sensor, causing a false indication of excessive airflow. Check air filter housing for evidence of water.
Тема: Ошибка P0101, ДМРВ (MAF), выбитые катализаторы, замена бензонасоса. Тах: GMT840 (Прочитано 35076 раз)