DTC Troubleshooting: P0102 (50)
DTC P0102:
 MAF Sensor Circuit Low Input
NOTE: Before you troubleshoot, record all freeze data and review the general troubleshooting information.
  1. Turn the ignition switch ON (II).
  1. Check the MAF SENSOR in the DATA LIST with the HDS.
Is about 0 gm/s or 0.29 V or less indicated?
YES -
Go to Step 3 .
NO -
Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the MAF sensor/IAT sensor 1 and the ECM.■
  1. Check the No. 3 ALTERNATOR (10 A) fuse in the under-dash fuse/relay box.
Is the fuse OK?
YES -
Go to Step 4 .
NO -
Repair short in the wire between the MAF sensor/IAT sensor 1 and the No. 3 ALTERNATOR (10 A) fuse, replace the fuse, then go to Step 23 .
  1. Turn the ignition switch OFF.
  1. Disconnect the MAF sensor/IAT sensor 1 5P connector.
  1. Turn the ignition switch ON (II).
  1. Measure voltage between MAF sensor/IAT sensor 1 5P connector terminal No. 3 and body ground.
Is there battery voltage?
YES -
Go to Step 8 .
NO -
Repair open in the wire between the No. 3 ALTERNATOR (10 A) fuse and the MAF sensor/IAT sensor 1, then go to Step 23 .
  1. Measure voltage between MAF sensor/IAT sensor 1 5P connector terminals No. 2 and No. 4.
Is there about 5 V?
YES -
Go to Step 9 .
NO -
Go to Step 14 .
  1. Turn the ignition switch OFF, and wait 2 minutes.
  1. Disconnect ECM connector No. 1 (96P).
  1. Check for continuity between MAF sensor/IAT sensor 1 5P connector terminal No. 5 and body ground.
Is there continuity?
YES -
Repair short in the wire between the MAF sensor/IAT sensor 1 and ECM connector No. 1 terminal No. 90, then go to Step 23 .
NO -
Go to Step 12 .
  1. Connect MAF sensor/IAT sensor 1 5P connector terminal No. 5 to body ground with a jumper wire.
  1. Check for continuity between ECM connector No. 1 terminal No. 90 and body ground.
Is there continuity?
YES -
Go to Step 18 .
NO -
Repair open in the wire between the MAF sensor/IAT sensor 1 and ECM connector No. 1 terminal No. 90, then go to Step 23 .
  1. Turn the ignition switch OFF, and wait 2 minutes.
  1. Disconnect ECM connector No. 1 (96P).
  1. Connect MAF sensor/IAT sensor 1 5P connector terminal No. 2 to body ground with a jumper wire.
  1. Check for continuity between ECM connector No. 1 terminal No. 30 and body ground.
Is there continuity?
YES -
Go to Step 23 .
NO -
Repair open in the wire between the MAF sensor/IAT sensor 1 and ECM connector No. 1 terminal No. 30, then go to Step 23 .
  1. Reconnect ECM connector No. 1 (96P).
  1. Connect MAF sensor/IAT sensor 1 5P connector terminals No. 2 and No. 5 with a jumper wire.
  1. Turn the ignition switch ON (II).
  1. Check the MAF SENSOR in the DATA LIST with the HDS.
Is about 0 gm/s or 0.29 V or less indicated?
YES -
Go to Step 28 .
NO -
Go to Step 22 .
  1. Reconnect all connectors.
  1. Turn the ignition switch ON (II).
  1. Reset the ECM with the HDS.
  1. Start the engine.
  1. Check for Temporary DTCs or DTCs with the HDS.
Is DTC P0102 indicated?
YES -
Check for poor connections or loose terminals at the MAF sensor/IAT sensor 1 and the ECM, then go to Step 1 .
NO -
Troubleshooting is complete. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.■
  1. Reconnect all connectors.
  1. Start the engine.
  1. Check for Temporary DTCs or DTCs with the HDS.
Is DTC P0102 indicated?
YES -
Check for poor connections or loose terminals at the MAF sensor/IAT sensor 1 and the ECM. If the ECM was updated, substitute a known-good ECM, then go to Step 30 . If the ECM was substituted, go to Step 1 .
NO -
If the ECM was updated, troubleshooting is complete. If the ECM was substituted, replace the original ECM. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.■