DTC Troubleshooting: P0670 (173)
DTC P0670:
 Lost Communication with Glow Plug Control Module (With DPF System)
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. Do the GLOW ON/OFF in the INSPECTION MENU with the HDS.
  1. Check for Temporary DTCs or DTCs with the HDS.
Is DTC P0670 indicated?
YES -
Go to Step 5 .
NO -
Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the glow plug control module and the ECM.■
  1. Turn the ignition switch OFF.
  1. Disconnect the glow plug control module 11P connector.
  1. Turn the ignition switch ON (II).
  1. Measure voltage between glow plug control module 11P connector terminal No. 6 and body ground.
Is there battery voltage?
YES -
Go to Step 9 .
NO -
Repair open in the wire between PGM-FI main relay 2 and the glow plug control module, then go to Step 24 .
  1. Turn the ignition switch OFF, and wait 2 minutes.
  1. Disconnect ECM connector No. 2 (58P).
  1. Check for continuity between glow plug control module 11P connector terminal No. 9 and body ground.
Is there continuity?
YES -
Repair short in the wire between the glow plug control module and ECM connector No. 2 terminal No. 46, then go to Step 24 .
NO -
Go to Step 12 .
  1. Connect glow plug control module 11P connector terminal No. 9 to body ground with a jumper wire.
  1. Check for continuity between ECM connector No. 2 terminal No. 46 and body ground.
Is there continuity?
YES -
Go to Step 14 .
NO -
Repair open in the wire between the glow plug control module and ECM connector No. 2 terminal No. 46, then go to Step 24 .
  1. Remove the jumper wire from the glow plug control module.
  1. Disconnect ECM connector No. 1 (96P).
  1. Check for continuity between glow plug control module 11P connector terminal No. 11 and body ground.
Is there continuity?
YES -
Repair short in the wire between the glow plug control module and ECM connector No. 1 terminal No. 75, then go to Step 24 .
NO -
Go to Step 17 .
  1. Connect glow plug control module 11P connector terminal No. 11 to body ground with a jumper wire.
  1. Check for continuity between ECM connector No. 1 terminal No. 75 and body ground.
Is there continuity?
YES -
Go to Step 19 .
NO -
Repair open in the wire between the glow plug control module and ECM connector No. 1 terminal No. 75, then go to Step 24 .
  1. Remove the jumper wire from the glow plug control module.
  1. Reconnect ECM connector No. 1 (96P) and ECM connector No. 2 (58P).
  1. Turn the ignition switch ON (ll).
  1. Measure voltage between glow plug control module 11P connector terminal No. 9 and body ground.
Is there battery voltage?
YES -
Go to Step 23 .
NO -
Go to Step 30 .
  1. Measure voltage between glow plug control module 11P connector terminal No. 11 and body ground.
Is there battery voltage?
YES -
NO -
Go to Step 30 .
  1. Turn the ignition switch OFF.
  1. Reconnect all connectors.
  1. Turn the ignition switch ON (II).
  1. Reset the ECM with the HDS.
  1. Do the GLOW ON/OFF in the INSPECTION MENU with the HDS.
  1. Check for Temporary DTCs or DTCs with the HDS.
Is DTC P0670 indicated?
YES -
Check for poor connections or loose terminals at the glow plug control module 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. Do the GLOW ON/OFF in the INSPECTION MENU with the HDS.
  1. Check for Temporary DTCs or DTCs with the HDS.
Is DTC P0670 indicated?
YES -
Check for poor connections or loose terminals at the glow plug control module and the ECM. If the ECM was updated, substitute a known-good ECM, then go to Step 32 . 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.■