Caterpillar — Test Step 9. Check the Voltage at the ECM
Testing & diagnosis · Engine ECM connectors P1
From a Caterpillar service manual covering: 3500B Engine, PM3516, PM3516 Power Module. Check it applies to your exact model before use.
Applies to: Caterpillar 3500B engine
Procedure
- Turn the ECS to the OFF/RESET position.
- Turn the ECS to the ON position, engine OFF.
- Measure analog voltage between P1-36 (997-OR) and P1-30 (993-BR).
- Measure digital voltage between P1-35 (700-OR) and P1-29 (998-BR).
- Turn the ECS to the OFF/RESET position.
Tools required
- Signal reading probes Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Analog supply 5.0 ± 0.5 VDC
- Digital supply 8.0 ± 0.5 VDC
Source: Caterpillar service manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.