03 Silverado Battery not charging message

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#1
Battery light "Red" started coming on and message display read battery not charging. Volt gauge on dash shows a hair over 14 volts, fluke shows 14.2. I have cleaned connections and am confused if I may have a alt going south. I checked the two wire connector at alt brown and grey, with key on grey wire has no voltage. I disconnected the C2 connector at PCM and checked pin 52 and 16 but dont know what i should have alldata sub does not indicate what voltage i should have at what wire. I did have a dtc of p1637.

Thanks for any clarification

-Paul
 
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#2
Is this the original battery ?

Ford_Dude
 
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#4
P1637"
CIRCUIT DESCRIPTION
The powertrain control module (PCM) uses the generator turn on signal circuit to control the generator. A high side driver within the PCM allows the PCM to turn the generator ON and OFF. When Generator operation is desired, the PCM sends a 5 volt signal to the voltage regulator via the generator turn on signal circuit. This causes the voltage regulator to begin controlling the generator field circuit. Once the Generator is enabled by the PCM, the voltage regulator controls generator output independently of the PCM. Under certain operating conditions, the PCM can turn Off the generator by turning Off the 5 volt signal on the generator turn on signal circuit. The PCM has fault detection circuitry which monitors the state of the generator turn on signal circuit. If the fault detection circuit senses a voltage other than what is expected, this DTC will set. The voltage regulator also contains fault detection circuitry. If the regulator detects a problem, the regulator will ground the generator turn on signal circuit, pulling the voltage low. This also causes the PCM to set the DTC.

CONDITIONS FOR RUNNING THE DTC


The ignition is on.
System voltage between 9.0 and 18.0 volts .
CONDITIONS FOR SETTING THE DTC


An improper voltage level has been detected on the generator L-terminal circuit.
The above conditions are present for at least 30 seconds .
ACTION TAKEN WHEN THE DTC SETS
The PCM stores conditions which were present when the DTC set as Failure Records only. This information will not be stored as Freeze Frame Records.

CONDITIONS FOR CLEARING THE MIL/DTC


The DTC becomes history when the conditions for setting the DTC are no longer present.
The history DTC clears after 40 malfunction free warm-up cycles.
The PCM receives a clear code command from the scan tool.

Ford_Dude
 
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#5
Thank you for your fast response Ford_Dude!!!!!!! I suspect there is something going on at the alt. will post a fix thread.
 

Gus

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#6
Condition
Some owners may comment that the Check Engine Light is illuminated and there is no driveability concern. Upon investigation, the technician may find codes P0120, P0220, P1516 or P1518. Also, technicians may note that low voltage codes P0562, P0563, P1637 or P1638 have been set.

Cause
The Tach module may set the code in error if it operates at a battery voltage of 4.5 to 5.0 volts.

Correction
If the vehicle has stored one of the low voltage codes, P0562, P0563, P1637 or P1638, follow the appropriate diagnostics for the low voltage code. In most cases, this will lead to correcting the concern without replacing any Electronic Throttle Control (ETC) components.

If codes P0120, P0220, P1516 or P1518 are present without any of the low voltage codes, the technician should observe the Engine RPM in the fault record.

• If the Engine RPM in the fault record is zero and the customer indicates that the vehicles has experienced a low voltage condition, the code should be cleared and the low voltage should be diagnosed and corrected.

• If the Engine RPM is zero and the customer indicates that there have been no low voltage conditions, then the P1516 diagnostic aids for intermittent concerns should be used to diagnose and correct the vehicle

• If the Engine RPM is greater than zero, then check for an obvious loose ground at G103 located next to the right cylinder head just below the head and mounted into the block. Also, check G104 located behind the left cylinder head. Then verify all electrical connections at the TAC module.