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DTC 444: Accelerometer Signal

  1. Check status message on Volvo Scan Tool (998-8686 ). If status message reads PERMANENT FAULT, SIGNAL TOO HIGH, go to next step. If status message reads PERMANENT FAULT, SIGNAL TOO LOW, go to step 10). If status message reads INTERMITTENT FAULT, SIGNAL TOO HIGH, go to step 11). If status message reads INTERMITTENT FAULT, SIGNAL TOO LOW, go to step 13).
  2. If PERMANENT FAULT, SIGNAL TOO HIGH is displayed on scan tool, turn ignition off. Disconnect accelerometer connector. Turn ignition on. Connect voltmeter between accelerometer connector terminal No. 1 and ground. If voltmeter reads 5 volts, go to next step. If voltmeter reads less than 5 volts, go to step 6). If voltmeter reads more than 5 volts, ensure accelerometer power lead is connected inside ECM to A/C pressure sensor power leads. A problem in one wire will affect both. Repair as necessary.
  3. Turn ignition off. Disconnect accelerometer connector. Connect an ohmmeter between accelerometer connector terminal No. 2 and ground. If ohmmeter reads zero ohms, go to next step. If ohmmeter does not read zero ohms, disconnect ECM connector. Check ECM connector for poor terminal contact. Repair as necessary. Repeat test. If ohmmeter now reads about zero ohms, problem was poor contact at ECM connector. If ohmmeter does not read about zero ohms, check wiring between accelerometer terminal No. 2 and ECM connector terminal B28 for an open circuit.
  4. Turn ignition on. Ensure accelerometer is disconnected. Connect voltmeter between accelerometer connector terminal No. 3 and ground. If voltmeter reads about 5 volts, go to next step. If voltmeter reads greater than 5 volts, check wiring between accelerometer connector terminal No. 3 and ECM connector terminal B32 for a short circuit to voltage. If voltmeter reads less than 5 volts, turn ignition off. Check ECM connector for poor terminal contact. Repeat test. If voltmeter now reads about 5 volts, problem was poor terminal contact. If voltmeter does not read about 5 volts, check wiring between accelerometer connector terminal No. 3 and ECM connector terminal B32 for an open circuit.
  5. Turn ignition on. Reconnect accelerometer. Erase DTC. Start and idle engine. If DTC reoccurs, replace accelerometer. If DTC does not reoccur, DTC was caused by poor terminal contact at accelerometer connector.
  6. Turn ignition off. Disconnect accelerometer connector. Wait 2 minutes. Connect an ohmmeter between accelerometer connector terminal No. 1 and ground. If ohmmeter reads about .2-1.5 k/ohms, DTC was caused by poor terminal contact at ECM. If ohmmeter reads less than .2-1.5 k/ohms, go to step 8). If ohmmeter reads greater than .2-1.5 k/ohms, go to next step.
  7. Check ECM connector for poor terminal contact. Repair as necessary. Connect ohmmeter between accelerometer connector terminal No. 1 and ground. If ohmmeter reads about .2-1.5 k/ohms, DTC was caused by poor ECM connection. If ohmmeter does not read .2-1.5 k/ohms, check wiring between accelerometer terminal No. 1 and ECM connector terminal B1 for an open circuit. Repair as necessary.
  8. Turn ignition off. Disconnect accelerometer connector. Disconnect A/C pressure sensor connector. Connect an ohmmeter between accelerometer connector terminal No. 1 and ground. If ohmmeter reads .2-1.5 k/ohms, replace A/C pressure sensor. If ohmmeter does not read .2-1.5 k/ohms, go to next step.
  9. Accelerometer power lead is connected inside ECM to A/C pressure sensor power lead. A problem with one lead will affect both. Check wiring between accelerometer terminal No. 1 and ECM connector terminal B1, A/C pressure sensor terminal No. 3 and ECM connector terminal B29. Repair as necessary.
  10. If fault is permanent and signal is too low, turn ignition off. Disconnect accelerometer. Turn ignition on. Connect voltmeter between accelerometer connector terminal No. 3 and ground. If voltmeter reads about 5 volts, retest using new accelerometer. If voltmeter does not read about 5 volts, check wiring between accelerometer connector terminal No. 3 and ECM connector terminal B32 for a short circuit to ground.
  11. If fault is intermittent and signal is too high, check accelerometer and ECM connectors for poor terminal contact. Repair as necessary. Check wiring between accelerometer connector terminal No. 1 and ECM connector terminal B1 for an intermittent open or short circuit to ground. Check wiring between accelerometer connector terminal No. 2 and ECM connector terminal B28 for an intermittent open circuit. Check wiring between accelerometer connector terminal No. 3 and ECM connector terminal B32 for an intermittent short circuit to voltage or intermittent open circuit.
  12. Also check for an intermittent short circuit to ground in wiring between accelerometer terminal No. 1 and ECM connector terminal B1, and between A/C pressure sensor terminal No. 3 and ECM connector terminal B29.
  13. If fault is intermittent and signal is too low, check wiring between accelerometer connector terminal No. 3 and ECM connector terminal B32 for an intermittent short circuit to ground.
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