DTC P0102 (19-21 9-Speed A/T)
DTC P0102 : Mass Air Flow (MAF) Sensor Circuit Low Voltage
Before you troubleshoot, review the general troubleshooting information - Refer to: How to Troubleshoot the Fuel and Emissions Systems .
| DTC Description | Confirmed DTC | Pending DTC |
|---|---|---|
| P0102 Mass Air Flow (MAF) Sensor Circuit Low Voltage |
DTC (PGM-FI)
- Problem verification
-1. Turn the vehicle to the ON mode, and wait 2 seconds.
- 2. Check the parameter (s) below with the HDS.
Signal Threshold Current conditions Values Unit Values Unit MAF SENSOR Less than 0.1 V Do the current condition (s) match the threshold?
YES
The failure is duplicated. Go to step 2.
NO
Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the MAF sensor/IAT sensor and the PCM. If the on-board snapshot of this DTC is recorded, try to reproduce the failure under the same conditions with the on-board snapshot - Refer to: How to Troubleshoot the Fuel and Emissions Systems .
- Open wire check (IG1 ACG line)
-1. Turn the vehicle to the OFF (LOCK) mode.
- 2. Disconnect the following connector.
MAF sensor/IAT sensor 5P connector - 3. Turn the vehicle to the ON mode.
- 4. Measure the voltage between test points 1 and 2.
Test condition
Vehicle ON mode MAF sensor/IAT sensor 5P connector: disconnected Test point 1 MAF sensor/IAT sensor 5P connector (female terminals) No. 1: Test point 2 Body ground Is there battery voltage?
YES
The IG1 ACG wire is OK. Go to step 3.
NO
Repair an open in the IG1 ACG wire between the MAF sensor/IAT sensor and the under dash fuse/relay box. If the wire is OK, do the PCM power and ground circuit troubleshooting - Refer to: PCM Power and Ground Circuit Troubleshooting (9-Speed A/T 2019 2020 2021) .
- Determine possible failure area (VGP line, others)
-1. Turn the vehicle to the OFF (LOCK) mode.
- 2. Measure the resistance between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode MAF sensor/IAT sensor 5P connector: disconnected Test point 1 MAF sensor/IAT sensor 5P connector (female terminals) No. 3: Test point 2 Body ground Is there 190-210 kΩ?
YES
Go to step 6.
NO
Go to step 4.
- Shorted wire check (VGP line)
-1. Jump the SCS line with the HDS, and wait more than 1 minute.
- 2. Disconnect the following connector.
PCM connector A (50P) - 3. Check for continuity between test points 1 and 2.
Test condition Vehicle OFF (LOCK) mode
MAF sensor/IAT sensor 5P connector: disconnected PCM connector A (50P): disconnected Test point 1 MAF sensor/IAT sensor 5P connector (female terminals) No. 3: Test point 2 Body ground Is there continuity?
YES
Repair a short in the VGP wire between the PCM (A20) and the MAF sensor/IAT sensor.
NO
The VGP wire is not shorted. Go to step 5.
- Open wire check (VGP line)
-1. Check for continuity between test points 1 and 2.
Test condition Vehicle OFF (LOCK) mode
MAF sensor/IAT sensor 5P connector: disconnected PCM connector A (50P): disconnected Test point 1 MAF sensor/IAT sensor 5P connector (female terminals) No. 3: Test point 2 PCM connector A (50P) No. 20 - Refer to:
PCM Connector for Inputs and Outputs (9-Speed A/T) (2019 2020 2021), orIs there continuity?
YES
The VGP wire is OK. Check for any authorized service information related to the DTCs or symptoms you are troubleshooting, or substitute a known-good PCM - Refer to: PCM Removal and Installation (9-Speed A/T 2019 2020 2021) , then recheck. If DTC P0102 goes away and the PCM was substituted, replace the original PCM - Refer to: PCM Removal and Installation (9-Speed A/T 2019 2020 2021) .
NO
Repair an open in the VGP wire between the PCM (A20) and the MAF sensor/IAT sensor.
- MAF sensor/IAT sensor check (substitution)
-1. Substitute a known-good MAF sensor/IAT sensor.
- 2. Reconnect all connectors.
- 3. Turn the vehicle to the ON mode.
- 4. Clear the DTC with the HDS.
- 5. Turn the vehicle to the OFF (LOCK) mode.
- 6. Start the engine.
- 7. Hold the engine speed at 2, 000 rpm without load (in P or N).
- 8. Check for Pending or Confirmed DTCs with the HDS.
DTC Description Confirmed DTC Pending DTC P0102 Mass Air Flow (MAF) Sensor Circuit Low Voltage Is DTC P0102 indicated?
YES
The MAF sensor/IAT sensor is OK. Check for any authorized service information related to the DTCs or symptoms you are troubleshooting, or substitute a known-good PCM - Refer to: PCM Removal and Installation (9-Speed A/T 2019 2020 2021), , then recheck. If DTC P0102 goes away and the PCM was substituted, replace the original PCM - Refer to: PCM Removal and Installation (9-Speed A/T 2019 2020 2021) .
NO