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Daniel Wilson
Daniel Wilson,
Category: Medium and Heavy Trucks
Satisfied Customers: 4390
Experience:  Owner at DJ Wilson
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I have a code 21 that comes on periodically I checked wires

Customer Question

I have a code 21 that comes on periodically
I checked for faulty wires and can't find any
Could it be a bad sensor or the actuator harness
Submitted: 9 months ago.
Category: Medium and Heavy Trucks
Expert:  Daniel Wilson replied 9 months ago.

Hi Kenneth my name is***** will be glad to help. That fault is for the 8 volt sensor supply below normal or above normal depending on the FMI

Expert:  Daniel Wilson replied 9 months ago.

41-03

21

8 Volt Supply Above Normal

41-04

21

8 Volt Supply Below Normal

Expert:  Daniel Wilson replied 9 months ago.

That is for the throttle pedal sensor. Check the supply voltage and harness to the throttle pedal sensor. the usual problem is a faulty ECM sending too much sensor or too little sensor signal voltage. If the harness and sensor check good then Try a test ECM for test purposes if available or replace the ECM and potentially the throttle sensor as well. Let me know

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