Coolant Temperature Gauge Needle Does Not Move at ALL

Check for fuel and emissions related DTCs.
If you find any, repair the problem, and clear the DTC before continuing.
Turn the ignition switch OFF, and connect PCM 32P connector A No. 31 terminal to body ground with a jumper wire.

Fig 1: Connecting PCM 32P Connector A No. 31 Terminal To Body Ground With A Jumper Wire
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Turn the ignition switch ON (II).
After 60 seconds or more, does the temperature gauge needle move to the Hot side?
1. YES - Check connections, If OK, substitute a known-good PCM and recheck (see HOW TO SUBSTITUTE THE PCM FOR TESTING ). If the symptom/indication goes away, replace the original PCM.
2. NO - Go to step 4.
Turn the ignition switch OFF, and disconnect PCM 32P connector A.
Check for continuity between PCM 32P connector A No. 31 terminal and gauge assembly 30P connector A No. 29 terminal.

Fig 2: Checking For Continuity Between PCM 32P Connector A No. 31 Terminal & Gauge Assembly 30P Connector A No. 29 Terminal
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?
1. YES - Replace the gauge assembly.
2. NO - Repair open in the wire between PCM 32P connector A No. 31 terminal and gauge assembly 30P connector A No. 29 terminal.