2006 MERCEDES-BENZ SPRINTER ignition

Symptom:
TRANS TEMP SENSOR ERRATIC
When Monitored and Set Condition:
TRANS TEMP SENSOR ERRATIC
When Monitored: When transmission temperature is below 170É C (338É F)
Set Condition: When there is a 10É C (18É F) variation between each transmission
temperature sensor read. If the DTC is reset (after an ignition cycle), the DTC will be set
to Stored (Intermittent) status.
POSSIBLE CAUSES
TRANSMISSION TEMP SENSOR WIRING
TCM - TRANS TEMP SENSOR ERRATIC
TEST ACTION APPLICABILITY
1NOTE: Low fluid level can be the cause of many transmission problems. If
the fluid level is low locate and repair the leak then check and adjust the
fluid level per the service information.
NOTE: Always perform diagnostics with a fully charged battery to avoid
false symptoms.
With the DRBIIIt, read the engine DTCs. Check and repair all engine DTCs prior to
performing transmission symptom diagnostics.
With the DRBIIIt, read and record all Transmission DTCs.
NOTE: Check connectors - Clean/repair as necessary. Poor pin to terminal
connections can set DTCs.
Using the wiring diagram/schematic as a guide, inspect the wiring and connectors.
Repair as necessary.
Most DTCs set on start up but some must be set by driving the vehicle such that all
diagnostic monitors have run.
Note: Verify flash level of transmission controller. Some problems are
corrected by software upgrades to the transmission controller.
NOTE: Check for any Technical Service Bulletins that may apply.
Perform this procedure prior to Symptom diagnosis.All
Continue
Go To 2
2 Ignition on, engine not running.
With the DRBIIIt, monitor the Transmission Temperature.
With the brakes firmly applied, place the gear selector in Drive.
While monitoring the DRBIIIt, wiggle the wires and connectors from the TCM to the
Transmission Solenoid Assembly.
Did the Transmission Temperature fluctuate while wiggling the wires?All
Ye s!Repair the wiring and/or connectors as necessary.
Perform NAG1 TRANSMISSION VERIFICATION TEST - VER 1.
No!Go To 3
120
TRANSMISSION - NAG1

TEST ACTION APPLICABILITY
3 Turn the ignition off to the lock position.
Disconnect the TCM C2 harness connector.
Place the gear selector to Drive (D).
Measure the resistance of the Transmission Temperature Sensor between the Temp
Sensor - P/N Switch circuit and the Sensor Ground circuit in the TCM C2 harness
connector.
Is the resistance between 500 ohms and 2500 ohms.All
Ye s!Go To 4
No!Check for a poor terminal to pin connections at the Solenoid
Assembly harness connector and repair as necessary. If no prob-
lems are found in the connector, replace the Transmission Tem-
perature Sensor - P/N Switch Assembly per the Service Informa-
tion.
Perform NAG1 TRANSMISSION VERIFICATION TEST - VER 1.
4 If there are no possible causes remaining, view repair. All
Repair
Replace the Transmission Control Module.
Perform NAG1 TRANSMISSION VERIFICATION TEST - VER 1.
5 Turn the ignition off to the lock position.
Disconnect the Transmission Solenoid harness connector.
NOTE: This procedure may set several DTCs in both the ECM and TCM.
Disregard and erase DTCs after this procedure.
With the gear selector in park, attempt to start the vehicle.
Does the vehicle start?All
Ye s!Replace the Transmission Temperature Sensor - P/N Switch
Assembly per the Service Information.
Perform NAG1 TRANSMISSION VERIFICATION TEST - VER 1.
No!Go To 6
6 Turn the ignition off to the lock position.
Disconnect the TCM C2 harness connector.
Disconnect the Transmission Solenoid Assembly harness connector.
Measure the resistance between ground and the Temp Sensor - P/N Switch circuit.
Is the resistance below 5.0 ohms?All
Ye s!Repair the Temp Sensor - P/N Switch circuit for a short to ground.
Perform NAG1 TRANSMISSION VERIFICATION TEST - VER 1.
No!Go To 7
7 Turn the ignition off to the lock position.
Disconnect the Transmission Solenoid Assembly harness connector.
Note: Check connectors - Clean/repair as necessary.
Disconnect the TCM C1 and C2 harness connectors.
Measure the resistance of the Temp Sensor - P/N Switch circuit to all other circuits
in the TCM C1 and C2 harness connectors.
Is the resistance below 5.0 ohms between any other circuit?All
Ye s!Repair the Temp Sensor - P/N Switch circuit for a short to other
circuits.
Perform NAG1 TRANSMISSION VERIFICATION TEST - VER 1.
No!Go To 8
123
TRANSMISSION - NAG1
TRANS TEMP SENSOR SHORTED ÐContinued

9.0 CONNECTOR PINOUTS
ELECTROHYDRAULIC CONTROL UNIT - BLACKCAV CIRCUIT FUNCTION
1 20BL/DG N3 INPUT SPEED SENSOR
2 16BR/GY MODULATION PRESSURE SOLENOID CONTROL
3 20BL/GY N2 INPUT SPEED SENSOR
4 20GY/BL TEMPERATURE SENSOR-P/N SWITCH
5- -
6 16BK SOLENOID SUPPLY VOLTAGE
7 20BK/BL SENSOR SUPPLY VOLTAGE
8 16WT/BL 2-3 SOLENOID CONTROL
9 16YL 3-4 SOLENOID CONTROL
10 16BK/RD SHIFT PRESSURE SOLENOID CONTROL
11 16YL/BL TCC SOLENOID CONTROL
12 20PK SENSOR GROUND
13 16WT 1-2/4-5 SOLENOID CONTROL
SHIFTER ASSEMBLY - BLACKCAV CIRCUIT FUNCTION
1- -
2 20GY/DG/RD LAMP DRIVER
3 20BL/DG K-ABS/SHIFTER ASSEMBLY
4 18BR GROUND
5 20BK/BL/RD BRAKE LAMP SWITCH
6 20DG/WT CAN C BUS (+)
7 20DG CAN C BUS (-)
8 18BK/DG TRANSMISSION RELAY OUTPUT
9 16WT/BL/RD FUSED IGNITION SWITCH OUTPUT (RUN-START)
10 16WT/RD BACK-UP LAMP
TRANSMISSION CONTROL MODULE C1 - BLACKCAV CIRCUIT FUNCTION
1 20BL K-TCM/RADIO
2- -
3- -
4- -
5- -
6- -
7- -
8- -
9- -
10 - -
23 - -
24 - -
25 - -
26 - -
27 - -
28 - -
29 16BK/DG TRANSMISSION RELAY OUTPUT
30 18BR GROUND
C
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N
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131
CONNECTOR PINOUTS

TRANSMISSION RELAY (RELAY BLOCK)CAV CIRCUIT FUNCTION
30 16BK/DG TRANSMISSION RELAY OUTPUT
85 16BR GROUND
86 16BK/YL FUSED IGNITION SWITCH OUTPUT (RUN-START)
87 16RD FUSED B(+)
87A - -
C
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133
CONNECTOR PINOUTS