Table 4, Target Carbon Pile Amp Draw by Alternator
Rating

Freightliner Service Bulletin, February 2014

Powernet Troubleshooting Guide: Batteries, Path, Alternator,
and Starter
FLA COE
FLB COE
FLD Conventional
Business Class
FLC 112 Conventional

> Century Class Conventional
> Argosy COE
Cargo
> Columbia

> 122SD and Coronado
> Business Class M2
> Cascadia
> 108SD/114SD

Remote Sense Check
11a DMM on POS and NEG of batt pack. (Undercharge check)
11b.DMM on POS and NEG of batt pack. (Overcharge check)

Key
Engine
Position
ENG OFF KEY OFF
ENG OFF KEY OFF

54-278
Freightliner
Service Bulletin

Carbon
Rec
Pile
Value
NO LOAD
NO LOAD

Accept
Value
less than
.05 V diff

Remote Sense
The remote sense circuit allows the alternator to directly
measure battery voltage, in addition to the measurement it
takes from the large cables. With these two voltage measurements, the alternator calculates the amount of voltage
drop over the large cables and adjusts its output to provide
the at-battery regulated voltage.
Freightliner vehicles come equipped with either Delco Remy
or Leece-Neville alternators, most of which have remote
sense.
Checks 11a and 11b – Remote Sense Check
11.1 With the key off, place the DMM probes at alternator
ground and remote sense post/terminal. See Fig. 14. Record the voltage.

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f151198

Fig. 14, Clip the DMM positive to the remote sense post
and the DMM negative to the alternator body.

11.2 Place the DMM probes at the alternator body and the
positive post of the alternator. Depending on the alternator,
the positive post may be labelled "POS" "B+" or "+". Record
the voltage.
The values should be within .05 V. If voltage is out of specification, then the remote sense circuit may be shorted or
open. First, check the remote sense fuse. The remote sense
07/16/2013
f151199
fuse is located in the Powernet Distribution Box (PNDB) on
EPA10 vehicles (see Fig. 15), and in the Powertrain Power
Distribution Module (PTPDM) on some EPA07 vehicles (see Fig. 15, EPA10 vehicles: 5 amp remote sense fuse, location D in the Powernet Distribution Box (PNDB).
Fig. 16). Refer to the applicable Workshop or Service
Manual or EZ wiring for the remote sense fuse location on
EPA07 or older vehicles. If the fuse is fine, look for opens or
shorts in the remote sense circuit.
If the remote sense fuse and circuit are fine, but the alternator is still overcharging, replace the alternator.

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Fig. 16, EPA07 Cascadia and Business Class M2 vehicles:
20 amp remote sense fuse, location F7 in the Powertrain
Power Distribution Module (PTPDM).

Freightliner Service Bulletin, February 2014

Page 11

54-278
Freightliner
Service Bulletin

Powernet Troubleshooting Guide: Batteries, Path, Alternator,
and Starter
FLA COE
FLB COE
FLD Conventional
Business Class
FLC 112 Conventional

> Century Class Conventional
> Argosy COE
Cargo
> Columbia

> 122SD and Coronado
> Business Class M2
> Cascadia
> 108SD/114SD

12 Check alternator mounting, pulley, and belt for proper condition and operation.

Check 12 – Alternator Pulley, Belt, and Mounting
Check the alternator drive belt for glazing, cracking, and
wear. See Fig. 18. Check the belt tensioner for proper
operation. Check that the alternator is securely fastened to
the engine and that the pulley is in proper alignment with the
drive belt system. Check for pulley damage. See Fig. 17.
Repair or replace as necessary.
See Group 01 – Engine in the applicable Workshop Manual
for more information on drive belt and pulley inspection.

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Fig. 17, Pulley Damage Requiring Pulley Replacement

07/15/2013

f151148a

Fig. 18, Types of Belt Damage Requiring Belt Replacement

Page 12

Freightliner Service Bulletin, February 2014

Powernet Troubleshooting Guide: Batteries, Path, Alternator,
and Starter
FLA COE
FLB COE
FLD Conventional
Business Class
FLC 112 Conventional

> Century Class Conventional
> Argosy COE
Cargo
> Columbia

> 122SD and Coronado
> Business Class M2
> Cascadia
> 108SD/114SD

54-278
Freightliner
Service Bulletin

Troubleshooting the Starting System
Before using the Starting System Troubleshooting, complete the Powernet Troubleshooting Worksheet. Batteries, cables, and the alternator must be checked for correct function before troubleshooting the starter. This
troubleshooting should not be performed until the Powernet Troubleshooting Worksheet has been completed.
Crank the engine with no loads (headlights, blower, etc.). Identify the symptom.
Symptom: Grinding Noise
Remove the starter and check the pinion and ring gear for damage. See Fig. 19.
• If damage is found, replace damaged parts as needed.
• If no damage is found, replace the starter.
Symptom: No Crank or Intermittent Crank

NOTE: Uncleared abutments should not happen more frequently than approximately 1 out of 100
starts.
Test the IMS input signal at the mag switch (see Fig. 20):
• If less than 9 V, FAIL; for Cascadia and Business Class M2 vehicles, use ServiceLink to check the Starter
Relay Output signal. For all other vehicles, use EZ Wiring to determine the source of the Starter Relay
Output signal. If the signal is present, check the circuit back to the signal output. Depending on the model
of vehicle, the output signal may originate from a module such as SAM Cab or directly from the ignition
switch. For Cascadia vehicles, check SAM Cab connector X19 pin 3 for continuity.
• If greater than or equal to 9 V, PASS; with the key off, rotate the engine 90 degrees using a barring tool.
Remove the tool, and try to crank the engine again:
− If the engine was hard to turn over and still does not crank, consult the engine manufacturer.
− If the engine cranks, shut down the engine, remove the starter, and inspect the starter pinion and
ring gear. See Inspecting the Ring Gear. Replace damaged parts if found. If no damage is found,
replace the starter
Symptom: Slow Turnover
If the ambient temperature is less than 32°F (0°C), slow turnover is normal.
If the ambient temperature is greater than 32°F (0°C), check the engine for faults and check the condition of the
engine oil. If fault codes are found, or the engine oil indicates an issue, consult the engine manufacturer. If there
are no fault codes, and the engine oil passes inspection, replace the starter.

Freightliner Service Bulletin, February 2014

Page 13

54-278
Freightliner
Service Bulletin

OK

Powernet Troubleshooting Guide: Batteries, Path, Alternator,
and Starter
FLA COE
FLB COE
FLD Conventional
Business Class
FLC 112 Conventional

> Century Class Conventional
> Argosy COE
Cargo
> Columbia

> 122SD and Coronado
> Business Class M2
> Cascadia
> 108SD/114SD

6

OK

7
5
4
3

2

1
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06/13/2013

f151163a

Fig. 19, Acceptable and Unacceptable Ring Gear Wear

1. Over Crank
Protection (OCP)
2. Insulated Ground
Terminal
3. Battery Terminal

4.
5.
6.
7.

Ground Terminal
Solenoid Switch
IMS Input Signal
Magnetic Switch
(IMS)

Fig. 20, Starter Components and Terminals

Warranty
This is an informational bulletin only. Warranty does not apply.

Page 14

Freightliner Service Bulletin, February 2014

PowerNet Assessment Worksheet − Perform Entire Worksheet in Order
Recorded Acceptable
BATTERIES CHECK
DMM (Digital Multimeter): Value
Value
1 Check battery pack voltage to determine state of charge. POS and NEG batt pack.
12.8V AGM
Charge pack to 100%. If unable, go to 3, "Break pack"
12.6V Flood
2 Remove surface charge: HVAC blower, lights on, 5 min.
3 Break pack into individual batteries and test each with an approved battery tester.
Batt 1: PASS or FAIL
(Remove NEG cables first!)
Batt 2: PASS or FAIL
Replace batteries, if instructed by the tester.
Batt 3: PASS or FAIL
All batteries must pass the battery tester evaluation before troubleshooting continues. Batt 4: PASS or FAIL
Continue to Path Check (For EPA07, see EPA07 Path Check Worksheet)
PATH CHECK − CABLE VOLTAGE DROP TEST (EPA10, EPA04 ONLY)
EPA10/EPA04: Alternator routes through starter post. Carbon pile on alternator will test alternator and starter cables.

Alternator Path Check
Carbon Pile:
4a POS alt, GND alt. Load at alternator−rated amps.
4b POS alt, GND alt. Load at alternator−rated amps.
Starter Path Check − EPA10, EPA04 Engines ONLY
Carbon Pile:
5a POS alt, GND alt. Load at 500 amps.
5b POS alt, GND alt. Load at 500 amps.
6

Recorded Acceptable
DMM:
Value
Value
POS alternator, POS batt pack +
Total less
NEG alternator, NEG batt pack +
than 0.7 V
=
DMM:
POS starter, POS batt pack
Total less
+
NEG starter, NEG batt pack
than 0.7 V
+
=
Check all cable connections for corrosion and torque. Repair if needed, then test again, until cables pass.
Continue to Loads Check

ADDITIONAL BATTERY LOADS CHECK
Recorded Acceptable
Key−off Loads
Value
Value
+
7 Key off, Load Disconnect Switch set to "Off." Wait 3 minutes for all loads to stop.
Add amps.
+
Set amp clamp to a lower range setting. Zero amp clamp away from the vehicle.
Total must
+
For each POS cable leaving batt pack, clamp the cable and record the amperage.
be less
If more than 1.0 amp, find sources of draw and remedy as needed.
than 1 amp.
=
Key−on Loads
8 Amp clamp on POS alt cable. ENG at IDLE, turn on driver’s normal use loads.
Total less
If load is more than 80% rated amps, find sources of draw and/or upgrade alternator.
than 80%
rated amps
Retest after remedying.
Continue to Charging Check
CHARGING SYSTEM CHECK − ALTERNATOR
Key
Carbon Recorded Acceptable
Engine Position Pile
Value
Value
9a DMM on POS and NEG of batt pack. (Undercharge check)
IDLE
KEY ON NO LOAD
13−15 V
9b DMM on POS and NEG of batt pack. (Overcharge check)
2000 RPM KEY ON NO LOAD
13−15 V
Carbon pile:
DMM:
70% of
within 1 V
10 POS and NEG of batt pack.
POS and NEG of batt pack. 2000 RPM KEY ON alt rated
of above
If value is outside acceptable range, replace alternator and retest system.
Remote Sense Check
11a DMM on Rem Sense post, NEG on alt GND.
ENG OFF KEY OFF NO LOAD
less than
11b DMM on POS of alternator, NEG on alt GND.
ENG OFF KEY OFF NO LOAD
.05 V diff
If remote sense voltage is outside range, but the remote sense fuse and circuit are ok, replace alternator.
12 Check alternator mounting, pulley, and belt for proper condition and operation.
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f020182

EPA07 Path Check Worksheet
Make sure to complete the Batteries Check portion of the PowerNet Assessment Worksheet before performing
this check.
On vehicles with EPA07 engines, the alternator and starter route to battery pack separately.
NOTE: This EPA07−specific worksheet is not necessary for EPA07 vehicles with jump start posts
connected to the starter. These vehicles can be tested using the Path Check in the Powernet
Assessment Worksheet by placing the carbon pile clamps on the jump start posts instead of the
alternator. Using the jump start posts will include them and their cables to the starter in the drop test.

EPA07 PATH CHECK WORKSHEET − CABLE VOLTAGE DROP TEST
EPA07 Engines: Alternator and starter route to battery pack separately.

Alternator Path Check
Carbon Pile:
4a POS alt, GND alt. Load at alternator−rated amps.
4b POS alt, GND alt. Load at alternator−rated amps.

DMM:
POS alternator, POS batt pack
NEG alternator, NEG batt pack

Recorded
Value
+
+
=

Acceptable
Value
Total less
than 0.7 V

Recorded Acceptable
Starter Path Check − EPA07 Engines ONLY
Value
Value
Amp Clamp and DMM location:
Engine:
5a Amp clamp around POS start cable for starter draw.
Crank engine, under 30 sec.
N/A
5b DMM on POS battery pack cable and POS starter post. Crank engine, under 30 sec. +
Less than
5c DMM on NEG battery pack cable and NEG starter post. Crank engine, under 30 sec. +
max V drop
Combine the voltage from the positive and negative cable drop tests.
in table.
=
Look up the crank amperage using the table below: the total of the recorded voltage drop values should not
exceed the value given as "Max Combined v Drop" in the table.
6 Check all cable connections for corrosion and torque. Repair if needed, then test again, until cables pass.
Continue to Loads Check on Powernet Assessment Worksheet

Amps
375−449
450−549
550−624
625−724
725−799
800−874
875−974
975−1025

Max. Acceptable
Combined V Drop

0.6
0.7
0.8
0.9
1.0
1.1
1.2
1.3

Max. Acceptable Combined V Drop by Amperage

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f020184