No Reduced Power Lamp (RPL) - Amigo & Rodeo

WARNING: This page is about a different car, the 2000 Isuzu VehiCROSS, 2000 Isuzu Trooper, 2000 Isuzu Rodeo, 2000 Isuzu Amigo, and 2000 Honda Passport. However, it is still accessible from the selected car via links, so may be relevant.

Perform On-Board Diagnostic II (OBD-II) System Check. See ON-BOARD DIAGNOSTIC II (OBD-II) SYSTEM CHECK in SELF-DIAGNOSTICS - INTRODUCTION article. After performing OBD-II system check, go to next step.
Attempt to start engine. If engine starts, go to next step. If engine does not start, go to step 11.
Check MAIN (100-amp), B+1 (60-amp), B+2 (50-amp), METER (15-amp), ECM (15-amp) and ENGINE (15-amp) fuses. If any of them were blown, go to step 14. If none of the fuses were blown, go to next step.
Turn ignition off. Disconnect instrument cluster connector. Turn ignition on. Connect test light to ground and probe ignition feed circuit at instrument cluster harness connector. If test light is on, go to next step. If test light is not on, go to step 15.
Turn ignition off. Disconnect Multiplex Control Unit (MCU). Check for faulty lamp driver circuit between PCM and MCU. If a problem was found, go to step 16. If no problems were found, go to next step.
Reconnect instrument cluster connector. Disconnect MCU. Connect fused jumper wire between ground and RPL driver circuit at MCU harness connector. Turn ignition on. If RPL comes on, go to next step. If RPL does not come on, see appropriate INSTRUMENT PANELS article in ACCESSORIES & EQUIPMENT.
Turn ignition off. With test light connected to ground, probe ignition feed circuit at MCU harness connector. Turn ignition on. If test light illuminates, go to next step. If test light does not illuminate, go to step 17.
Turn ignition off. Disconnect PCM harness connectors. Check for faulty circuit between PCM and MCU harness connectors. If a problem was found, go to step 18. If no problems were found, go to next step.
Check MCU ground connection and circuit. If problem was found, go to step 19. If no problem was found, go to next step.
Check for damaged terminals at MCU. If problem was found, go to step 20. If no problem was found, go to next step.
Turn ignition on. With test light connected to ground, probe ignition feed circuit at PCM harness connector. If test light illuminates, go to next step. If test light did not illuminate, go to step 21.
Check PCM ground connection and circuit. If problem was found, go to step 23. If no problem was found, go to next step.
Check for damaged terminals at PCM. If problem was found, go to step 24. If no problem was found, go to next step.
Replace blown fuse. Retest system.
Locate and repair open circuit in battery feed to instrument cluster. Retest system.
Locate and repair open circuit between instrument cluster and MCU. Retest system.
Locate and repair open circuit in battery feed to MCU. Retest system.
Locate and repair open circuit between PCM and MCU. Retest system.
Locate and repair faulty ground circuit for MCU. Retest system.
Replace MCU. Retest system.
Substitute known-good relay for PCM main relay. Retest system. If problem is still present, go to next step.
Repair open ignition feed circuit. Retest system.
Locate and repair faulty ground circuit for PCM. Retest system.
Replace and reprogram PCM. See PROGRAMMING . Retest system.
Reconnect all harness connectors. Turn ignition on. Use scan tool to select RPL DASH LAMP CONTROL. Command RPL to turn ON. If RPL turned on, repairs are complete. If RPL did not turn on, go to next step.
Turn ignition off. Disconnect PCM harness connectors. Check for faulty circuit between PCM and DLC. If problem was found, go to next step. If no problem was found, go back to step 24.
Locate and repair problem in circuit between PCM and DLC. Go back to step 25.