DTC Troubleshooting: P0698 (181)
DTC P0698:
 Sensor Reference Voltage C Circuit Low Voltage
NOTE: Before you troubleshoot, record all freeze data and review the general troubleshooting information.
  1. Turn the ignition switch ON (II).
  1. Clear the DTC with the HDS.
  1. Check for Temporary DTCs or DTCs with the HDS.
Is DTC P0698 indicated?
YES -
Go to Step 4 .
NO -
Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the FRP sensor, the MAF sensor/IAT sensor 1, the MAP sensor/IAT sensor 2, and the ECM.■
  1. Turn the ignition switch OFF, and wait 2 minutes.
  1. Disconnect the connectors from these sensors:
    • FRP sensor
    • MAF sensor/IAT sensor 1
    • MAP sensor/IAT sensor 2
  1. Turn the ignition switch ON (II).
  1. Clear the DTC with the HDS.
  1. Reconnect the connector from each of these sensors, one at a time:
    • FRP sensor
    • MAF sensor/IAT sensor 1
    • MAP sensor/IAT sensor 2
  1. Check for Temporary DTCs or DTCs with the HDS.
Is DTC P0698 indicated?
YES -
Replace the sensor that indicated DTC when reconnected, then go to Step 13 .
NO -
Go to Step 10 .
  1. Turn the ignition switch OFF, and wait 2 minutes.
  1. Disconnect ECM connectors No. 1 (96P).
  1. Check for continuity between body ground and ECM connector No. 1 terminals No. 6, No. 7, No. 30 individually.
Is there continuity?
YES -
Repair short in the wire between the ECM connector terminals and these sensors, then go to Step 13 .
  • FRP sensor and ECM connector No. 1 terminal No. 7
  • MAF sensor/IAT sensor 1 and ECM connector No. 1 terminal No. 30
  • MAP sensor/IAT sensor 2 and ECM connector No. 1 terminal No. 6
NO -
Go to Step 17 .
  1. Reconnect all connectors.
  1. Turn the ignition switch ON (II).
  1. Reset the ECM with the HDS.
  1. Check for Temporary DTCs or DTCs with the HDS.
Is DTC P0698 indicated?
YES -
Check for poor connections or loose terminals at the FRP sensor, the MAF sensor/IAT sensor 1, the MAP sensor/IAT sensor 2, 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. Check for Temporary DTCs or DTCs with the HDS.
Is DTC P0698 indicated?
YES -
Check for poor connections or loose terminals at the FRP sensor, the MAF sensor/IAT sensor 1, the MAP sensor/IAT sensor 2, and the ECM. If the ECM was updated, substitute a known-good ECM, then recheck. 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.■