alternator, the positive post may be labelled "POS" "B+" or "+". Record the voltage.

NOTE: Ground may be on a post, not the body, for some Leece Neville alternators.
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 fuse is located in the Powernet
Distribution Box (PNDB) on EPA10 vehicles (see Fig. 15), and in the Powertrain PowerNet Distribution Module
(PTPDM) on EPA07 vehicles (see 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.

Freightliner Service Bulletin, 8/31/2017

Page 13

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
> New Cascadia

07/16/2013

f151199

Fig. 15, EPA10 vehicles: 5 amp remote sense fuse,
location D in the Powernet Distribution Box (PNDB).
02/17/2017

f151198

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

07/16/2013

f151200

Fig. 16, EPA07 vehicles: 20 amp remote sense fuse,
location F7 in the Powernet Distribution Module
(PTPDM).

If the remote sense fuse and circuit are fine, but the alternator is still overcharging, replace the alternator.

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

Check 12 – Alternator Pulley, Belt, and Mounting

Page 14

Freightliner Service Bulletin, 8/31/2017

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

54-278
Freightliner
Service Bulletin

> Business Class M2
> Cascadia
> 108SD/114SD
> New Cascadia

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 the vehicle workshop manual Group 01 – Engine for more information on drive belt and pulley inspection.

07/15/2013

f151148a

Fig. 17, Types of Belt Damage Requiring Belt Replacement

01/19/2010

f151149

Fig. 18, Pulley Damage Requiring Pulley Replacement

Freightliner Service Bulletin, 8/31/2017

Page 15

54-278

Powernet Troubleshooting Guide: Batteries, Path, Alternator,
and Starter

Freightliner
Service Bulletin

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
> New Cascadia

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 mag switch using a DMM (positive probe on the IMS input signal, negative probe on a known good
ground) while cranking:
• If less than 9 V, FAIL:
− For Cascadia, use DiagnosticLink to check the Starter Relay Output signal. If the signal is present,
check SAM Cab connector X19 pin 3 for continuity.
− For Business Class M2, use ServiceLink to check the Starter Relay Output signal. If the signal is
present, check bulkhead module connector B4 pin B for continuity.
− For all other models, troubleshoot the circuit and check all of the applicable starter interlocks and
control systems. Find more information using PartsPro and EZwiring.
• 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.

Page 16

Freightliner Service Bulletin, 8/31/2017

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

54-278
Freightliner
Service Bulletin

> Business Class M2
> Cascadia
> 108SD/114SD
> New Cascadia

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.

OK

6

OK

7
5
4
3

2

1
f151145a

08/28/2013

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.

PowerNet Assessment Worksheet - Do Entire Worksheet in Order
(Checks 1 to 12)
IMPORTANT: Record the initial value of each check on the worksheet before performing repairs.
BATTERIES CHECK
1.
2.
3.

DMM (Digital Multimeter):
POS and NEG batt pack.

Check battery pack voltage to determine state of charge.
Charge pack to 100%. If unable, go to 3, "Break pack."
Remove surface charge: HVAC blower, lights on, 5 min.
Break pack into individual batteries and test each with an approved battery tester.
(Remove NEG cables first!)
Replace batteries if instructed by the tester.

Freightliner Service Bulletin, 8/31/2017

Rec
Value

Accept
Value
12.8V AGM
12.6V Flood

Batt 1: PASS or FAIL
Batt 2: PASS or FAIL
Batt 3: PASS or FAIL

Page 17

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
> New Cascadia

All batteries must pass the battery tester evaluation before troubleshooting continues.

Batt 4: PASS or FAIL

PATH CHECK - CABLE VOLTAGE DROP TEST
Alternator Path Check
Carbon Pile:
DMM:
4a. POS alternator, GND alternator. Load at alternator-rated amps. POS alternator, POS batt pack
4b. POS alternator, GND alternator. Load at alternator-rated amps. NEG alternator, NEG batt pack
Combine the voltage from the positive and negative cable drop tests.

Rec
Value

Accept
Value

+
+
=

Total less
than 0.7 V

IMPORTANT: EPA10/EPA04 and EPA07 vehicles require different starter path checks because of
differences in cable routing.
IMPORTANT: If the positive alternator cable is smaller than 2/0 AWG, use "Starter Path Check - EPA07."
NOTE: EPA07 vehicles with jump start posts connected to the starter can be tested using the EPA10/EPA04
check by placing the carbon pile clamps on the jump start posts instead of the alternator in 5a and 5b.
Starter Path Check — EPA10, EPA04 Engines
Rec
Value
Carbon Pile:
DMM:
5a. POS alternator, GND alternator. Load at 500 amps.
POS starter, POS batt pack
+
5b. POS alternator, GND alternator. Load at 500 amps.
NEG starter, NEG batt pack +
Combine the voltage from the positive and negative cable voltage drop tests.
=
6. Check all cable connections for corrosion and torque. Repair or replace if needed, then test again.

Starter Path Check — EPA07 Engines
Rec
Value
Amp Clamp and DMM Location:
Engine:
5a. Amp clamp around POS starter cable for starter draw.
Crank engine, under 30 sec.
5b. DMM on POS battery pack cable and POS starter post.
Crank engine, under 30 sec. +
5c. DMM on NEG battery pack cable and NEG starter post.
Crank engine, under 30 sec. +
Combine the voltage from the positive and negative cable voltage drop tests.
=
6. Check all cable connections for corrosion and torque. Repair or replace if needed, then test again.

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

Accept
Value
Total less
than 0.7 V

Accept
Value
N/A
Less than
max V drop
in Table 5.

Max. Acceptable Combined V Drop
0.6
0.7
0.8
0.9
1.0
1.1
1.2
1.3

Table 5, for Check 5, Max. Acceptable Combined V Drop by Amperage

Page 18

Freightliner Service Bulletin, 8/31/2017

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

54-278
Freightliner
Service Bulletin

> Business Class M2
> Cascadia
> 108SD/114SD
> New Cascadia

ADDITIONAL BATTERY LOADS CHECK
Key-off Loads
7. Key off, Load Disconnect Switch set to "Off" (if equipped). Wait 10 minutes for all loads to
stop.
Set amp clamp to a lower range setting. Zero amp clamp away from the vehicle.
For each POS cable leaving batt pack, clamp the cable and record the amperage.
If more than 1.0 amp, find sources of drain and remedy as needed.
Key-on Loads
8. Amp clamp on POS alt cable. ENG at IDLE, turn on driver’s normal use loads.
If load is more than 80% rated amps, find sources of draw and/or upgrade alternator.
Retest after remedying.

CHARGING SYSTEM CHECK - ALTERNATOR

Engine
Throttle
9a. DMM on POS and NEG of batt pack. (Undercharge check) IDLE
9b. DMM on POS and NEG of batt pack. (Overcharge check) PARTIAL
9c. DMM on POS and NEG of batt pack. (Overcharge check) WIDE OPEN
Carbon Pile:
DMM:

Key
Position
KEY ON
KEY ON
KEY ON

Rec
Value
+
+
+
=

Carbon
Rec
Pile
Value
NO LOAD
NO LOAD
NO LOAD

70% of alt
KEY ON rated
70% of alt
10b.POS and NEG of batt pack.
POS and NEG of batt pack. WIDE OPEN KEY ON rated
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
NO LOAD
OFF
KEY
11b.DMM on POS of alternator, NEG on alt GND.
ENG OFF
OFF
NO LOAD
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.

10a.POS and NEG of batt pack.

Freightliner Service Bulletin, 8/31/2017

POS and NEG of batt pack. PARTIAL

Accept
Value
Add amps.
Total must
be less than
1 amp.

Total less
than 80%
rated amps.

Accept
Value
13.2-14.8 V
13.2-14.8 V
13.2-14.8 V
Within .2 V
of Check 9
Within .2 V
of Check 9

Less than
.05 V diff

Page 19