OK. Here's how to diagnose the P1298 error. DTC P1298: ELD Circuit High Voltage
1. Reset the ECM/PCM (see HOW TO RESET THE ECM/PCM ).
2. Start the engine
3. Turn on the headlights. Is DTC P1298 indicated?
YES - Go to step 4.
NO - Intermittent failure, system is OK at this time. Check for poor
connections or loose terminals at the ELD and at the ECM/PCM.
4. Turn the ignition switch and headlights OFF.
5. Disconnect the ELD 3P connector.
6. Turn the ignition switch ON (II).
7. Measure voltage between body ground and ELD 3P connector terminal No. 1.
Is there battery voltage?
YES - Go to step 8.
NO - Check the No. 4 ACG (10A) fuse in the under-dash fuse/relay box.
If the fuse is OK, repair open in the wire between the No. 4 ACG (10A)
fuse and the ELD.
8. Turn the ignition switch OFF.
9. Connect ELD 3P connector terminal No. 3 to body ground with a jumper wire.
10. Disconnect ECM/PCM connector E (31P).
11. Check for continuity between body ground and ECM/PCM connector terminal E15.Is there continuity?
YES - Go to step 12.
NO - Repair open in the wire between the ECM/PCM (E15) and the ELD.
12. Check for continuity between ELD 3P connector terminal No. 2 and body ground. Is there continuity?
YES - Go to step 13.
NO - Repair open in the wire between ELD and G201.
13. Reconnect the ELD 3P connector and ECM/PCM connector E (31P).
14. Start the engine and let it idle.
15. While measuring voltage between ECM/PCM connector terminals A24 and E15, turn the headlights on (high).Does the voltage drop?
YES - Update the ECM/PCM if it does not have the latest software, or
substitute a known-good ECM/PCM, then recheck. If the
symptom/indication goes away with a known-good ECM/PCM, replace the
NO - Replace the ELD.