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Miscellaneous Troubleshooting
Test Measurement
Stop Lamp Switch to Ground 9 to 17 VDC
For all tests below, take all measurements at ECU
harness connector pins in order to check wire harness
and sensor. Probe the connector carefully so that the
terminals are not damaged.
Dynamometer Test Mode (ATC Indicator Lamp
Continuously Illuminated)
1. Clear the dynamometer test mode by depressing and
releasing the blink code switch three times (or use an
off-board diagnostic tool).
2. Apply and release service brake, does lamp extinguish?
3. Verify brake lamp switch is connected to ECU via hard
wire or J1939.
4. With service brake released, check for presence of stop
lamp bulb.
Stop Lamp Switch Test
1. With the service brake applied, measure the system
voltage (9 to 17 VDC) stop lamp switch input to ECU.
ABS Indicator Lamp
1. Verify diagnostic blink code switch is open when not
activated.
PMV Commons
1. Measure resistance between any common (PMV, TCV,
and Diff.) and voltage or ground.
Test Measurement
Any PMV, TCV, or Diff. Open Circuit (no continuity)
Common to Voltage
or Ground
Retarder Relay
1. Measure resistance between retarder disable output of
EC-60
™
controller and voltage / ground.
Test Measurement
Retarder disable to Voltage Open Circuit (no continuity)
or Ground
2. Verify vehicle has retarder relay.
3. Verify proper wiring from ECU to retarder relay.
Differential Lock Solenoid
1. Measure resistance between Diff lock solenoid and
voltage or ground.
Test Measurement
Diff. Lock Solenoid to Voltage Open Circuit (no continuity)
or Ground
Cab-mount ECU: Looking into
wire harness connector
Connector Pin PMV Location
X1 10 Retarder
18 Way 12 ABS WL
5 Stop Lamp Switch
X2 13 PMV Left Steer Axle Common
18 Way 14 PMV Right Steer Axle Common
15 PMV Left Drive Axle Common
16 PMV Right Drive Axle Common
8 Diff. Lock Solenoid
X3 13 TCV Common
15 Way 14 Diff. Lock Solenoid Common
15 PMV Left Additional Axle Common
16 PMV Right Additional Axle Common
Frame-mount ECU: Looking into
wire harness connector
Connector Pin PMV Location
4 TCV Common
X1 9 Stop Lamp Switch
18 Way 12 ABS WL Ground
15 ABS WL Interlock
17 Retarder
18 ABS WL
3 PMV Left Steer Axle Common
X2 6 PMV Right Steer Axle Common
18 Way 9 PMV Right Drive Axle Common
12 PMV Left Drive Axle Common
2 Diff Lock Solenoid
X3 3 Diff Lock Solenoid Common
15 Way 6 PMV Left Additional Axle Common
9 PMV Right Additional Axle Common